Unlike similar tools, Eclipse SDK provides complete support for developing server side applications and, with the help of the very popular Web Tools Platform you can simplify the development of Web and Java EE apps. As an added advantage, the Eclipse SDK can even be used to easily develop packages for the popular Mathematica software. Eclipse IDE for Java EE Developers. 304 MB; 1,652,972 DOWNLOADS; Tools for Java developers creating Java EE and Web applications, including a Java IDE, tools for Java EE, JPA, JSF, Mylyn, EGit and others. Windows 32-bit x8664 Linux x8664. Eclipse IDE for Java Developers. Download Package Eclipse IDE for Java EE Developers Note: Eclipse IDE depends on JDK/JRE so make sure that you have JDK/JRE installed on your computer. And configure the JAVAHOME and PATH environment variables properly (See: How to set environment variables for Java using command line ).
Eclipse (@ www.eclipse.org) is an open-source Integrated Development Environment (IDE) supported by IBM. Eclipse is popular for Java application development (Java SE and Java EE) and Android apps. It also supports C/C++, PHP, Python, Perl, and other web project developments via extensible plug-ins. Eclipse is cross-platform and runs under Windows, Linux and macOS. Eclipse Versions
The various versions are:
Eclipse 1.0 (November 7, 2001): based on an earlier Java IDE called VisualAge from IBM.
Eclipse 2.0 (June 28, 2002)
Eclipse 2.1 (March 28, 2003)
Eclipse 3.0 (June 25, 2004)
Eclipse 3.1 (June 28, 2005)
Eclipse 3.2 (June 30, 2006) (Callisto - named after one of the Jupiter's Galilean moons): started annual simultaneous release of all the related Eclipse projects.
Eclipse 3.3 (June 25, 2007) (Europa - named after another Jupiter's Galilean moons)
Eclipse 3.4 (June 19, 2008) (Ganymede - named after yet another Jupiter's Galilean moons)
Eclipse 3.5 (June 12, 2009) (Galileo - named after the great 17th century scientist and astronomer Galileo Galilei)
Eclipse 3.6 (June 23, 2010) (Helios - named after god of the sun in Greek Mythology)
Eclipse 3.7 (June 23, 2011) (Indigo)
Eclipse 4.2 (June 27, 2012) (Juno)
Eclipse 4.3 (June 2013) (Kepler)
Eclipse 4.4 (June 2014) (Luna)
Eclipse 4.5 (June 2015) (Mars)
Eclipse 4.6 (June 2016) (Neon)
Eclipse 4.7 (June 2017) (Oxygen)
Eclipse 4.8 (June 2018) (Photon)
Eclipse 2018-09 (4.9)
Eclipse 2018-12 (4.10)
Eclipse 2019-03 (4.11)
Eclipse 2019-06 (4.12)
Eclipse 2019-09 (4.13)
Eclipse 2019-12 (4.14) How to Install Eclipse IDE 2019-12 for Java Developers How to Install Eclipse on Windows Step 0: Install JDK
To use Eclipse for Java programming, you need to first install Java Development Kit (JDK). Read 'How to Install JDK for Windows'. Step 1: Download
Download Eclipse from https://www.eclipse.org/downloads. Under 'Get Eclipse IDE 2019-12' Click 'Download Packages'. For beginners, choose the ' Eclipse IDE for Java Developers ' and ' Windows 64-bit ' (e.g., ' eclipse-java-2019-12-R-win32-x86_64.zip ' - about 201MB) Download. Step 2: Unzip
To install Eclipse, simply unzip the downloaded file into a directory of your choice (e.g., ' c:myProject ').
I prefer the zip version, because there is no need to run any installer. Moreover, you can simply delete the entire Eclipse directory when it is no longer needed (without running any un-installer). You are free to move or rename the directory. You can install (unzip) multiple copies of Eclipse in the same machine. How to Install Eclipse on macOS
To use Eclipse for Java programming, you need to first install JDK. Read 'How to install JDK for macOS'.
To install Eclipse:
Goto http://www.eclipse.org/downloads/. Under 'Get Eclipse IDE 2019-12' Click 'Download Packages'. For beginners, select ' Eclipse IDE for Java Developers ' and ' Mac Cocoa 64-bit '. You will receive a DMG file (e.g., ' eclipse-java-2019-12-R-macosx-cocoa-x86_64.dmg ').
Double-click the downloaded Disk Image (DMG) file. Follow the screen instructions to install Eclipse. Eclipse will be installed under ' /Applications/eclipse '. (To confirm!) How to Install Eclipse on Ubuntu Linux
Eclipse comes with many flavors (See 'Eclipse Packages' @ https://www.eclipse.org/downloads/compare.php):
To use Eclipse for Java programming, choose 'Eclipse IDE for Java Developers' (JavaSE) or 'Eclipse IDE for Java EE Developers' (JavaEE). You need to first install JDK. Read 'How to install JDK on Ubuntu'.
To use Eclipse for PHP programming, choose 'Eclipse IDE for PHP Developers'.
To use Eclipse for C/C++ programming, choose 'Eclipse IDE for C/C++ Developers'.
Nonetheless, you can install any package, and then add more features when needed.
To install Eclipse (e.g, for Java Programming):
Download Eclipse from http://www.eclipse.org/downloads/. Under 'Get Eclipse IDE 2019-12' Click 'Download Packages'. Choose 'Eclipse IDE for Java Developers' for Java SE program development; or 'Eclipse IDE for Java EE Developers' for developing webapps Linux 64-bit. You will receive a tarball (e.g., ' eclipse-java-2019-12-R-linux-gtk-x86_64.tar.gz ') in the ' /Downloads ' folder.
We shall install Eclipse under /usr/local .
To run Eclipse, open the ' /usr/local/eclipse ' folder and click on the 'Eclipse' icon; or start a 'Terminal', enter 'eclipse'. Lock Eclipse on Launcher
Simply start Eclipse. Right-click the Eclipse icon Lock to Launcher.
(For older version - If the above don't work) Create a /usr/share/applications/eclipse.desktop file with the following contents:
Start Eclipse, right-click on the Eclipse icon on launcher lock to launcher. Writing your First Java Program in Eclipse Step 0: Launch Eclipse
Launch Eclipse by running ' eclipse.exe ' from the Eclipse installed directory.
Choose an appropriate directory for your workspace , i.e., where you would like to save your files (e.g., c:myProjecteclipse for Windows) Launch.
If the 'Welcome' screen shows up, close it by clicking the 'close' button next to the 'Welcome' title. Step 1: Create a new Java Project For each Java application, you need to create a project to keep all the source files, classes and relevant resources.
To create a new Java project:
Choose 'File' menu 'New' 'Java project' (or 'File' 'New' 'Project' 'Java project').
The 'New Java Project' dialog pops up.
In 'Project name', enter ' FirstProject '.
Check 'Use default location'.
In 'JRE', select 'Use default JRE (currently 'JDK11.0.x')'. But make sure that your JDK is 1.8 and above.
In 'Project Layout', check 'Use project folder as root for sources and class files'. Push ' Finish ' button.
In 'Create module-info.java' dialog, Click 'Don't Create' . (Note: For easier version of Eclipse, you need to use the 'Next' Button in the previous step, and uncheck 'Create module-info.java file'). Step 2: Write a Hello-world Java Program
In the 'Package Explorer' (left pane) Right-click on ' FirstProject ' (or use the 'File' menu) New Class.
The 'New Java Class' dialog pops up.
In 'Source folder', keep the 'FirstProject'.
In 'Package', delete the content if it is not empty.
In 'Name', enter ' Hello '.
Check ' public static void main(String[] args) '.
Don't change the rest. Push 'Finish' button.
The source file ' Hello.java ' opens on the editor panel (the center pane). Enter the following codes: Step 3: Compile Execute the Java Program
There is no need to compile the Java source file in Eclipse explicitly. It is because Eclipse performs the so-called incremental compilation , i.e., the Java statement is compiled as and when it is entered.
To run the program, right-click anywhere on the source file ' Hello.java ' (or choose 'Run' menu) Run As Java Application.
The output 'Hello, world!' appears on the Console panel (the bottom pane). NOTES:
You should create a NEW Java project for EACH of your Java application.
Nonetheless, Eclipse allows you to keep more than one programs in a project, which is handy for writing toy programs (such as your tutorial exercises). To run a particular program, open and right-click on the source file Run As Java Application.
Clicking the 'Run' button (with a 'Play' icon) runs the recently-run program (based on the previous configuration). Try clicking on the 'down-arrow' besides the 'Run' button. Correcting Syntax Errors
Eclipse performs incremented compilation, as and when a source 'line' is entered. It marked a source line having syntax error with a RED CROSS. Place your cursor at the RED CROSS to view the error message.
You CANNOT RUN the program if there is any syntax error (marked by a RED CROSS before the filename). Correct all the syntax errors; and RUN the program.
HINTS: In some cases, Eclipse shows a ORANGE LIGHT-BULB (for HINTS) next to the ERROR RED-CROSS (Line 5 in the above diagram). You can click on the LIGHT-BULB to get a list of HINTS to resolve this particular error, which may or may not work!
SYNTAX WARNING: marked by a orange triangular exclaimation sign. Unlike errors, warnings may or may not cause problems. Try to fix these warnings as well. But you can RUN your program with warnings. Read the Eclipse Documentation
At a minimum, you SHOULD browse through Eclipse's ' Workbench User Guide ' and ' Java Development User Guide ' - accessible via the Eclipse's 'Welcome' page or 'Help' menu. This will save you many agonizing hours trying to figure out how to do somethings later. Debugging Programs in Eclipse
Able to use a graphics debugger to debug program is crucial in programming. It could save you countless hours guessing on what went wrong. Step 0: Write a Java Program
The following program computes and prints the factorial of n ( =1*2*3*...* n ). The program, however, has a logical error and produce a wrong answer for n =20 (' The Factorial of 20 is -2102132736 ' - a negative number?!).
Let's use the graphic debugger to debug the program. Step 1: Set an Initial Breakpoint
A breakpoint suspends program execution for you to examine the internal states (e.g., value of variables) of the program. Before starting the debugger, you need to set at least one breakpoint to suspend the execution inside the program. Set a breakpoint at main() method by double-clicking on the left-margin of the line containing main() . A blue circle appears in the left-margin indicating a breakpoint is set at that line. Step 2: Start Debugger
Right click anywhere on the source code (or from the 'Run' menu) 'Debug As' 'Java Application' choose 'Yes' to switch into 'Debug' perspective (A perspective is a particular arrangement of panels to suits a certain development task such as editing or debugging). The program begins execution but suspends its operation at the breakpoint, i.e., the main() method.
As illustrated in the following diagram, the highlighted line (also pointed to by a blue arrow) indicates the statement to be executed in the next step. Step 3: Step-Over and Watch the Variables and Outputs
Click the 'Step Over' button (or select 'Step Over' from 'Run' menu) to single-step thru your program. At each of the step, examine the value of the variables (in the 'Variable' panel) and the outputs produced by your program (in the 'Console' Panel), if any. You can also place your cursor at any variable to inspect the content of the variable.
Single-stepping thru the program and watching the values of internal variables and the outputs produced is the ultimate mean in debugging programs - because it is exactly how the computer runs your program! Step 4: Breakpoint, Run-To-Line, Resume and Terminate
As mentioned, a breakpoint suspends program execution and let you examine the internal states of the program. To set a breakpoint on a particular statement, double-click the left-margin of that line (or select 'Toggle Breakpoint' from 'Run' menu).
'Resume' continues the program execution, up to the next breakpoint, or till the end of the program.
'Single-step' thru a loop with a large count is time-consuming. You could set a breakpoint at the statement immediately outside the loop (e.g., Line 11 of the above program), and issue 'Resume' to complete the loop.
Alternatively, you can place the cursor on a particular statement, and issue 'Run-To-Line' from the 'Run' menu to continue execution up to the line.
'Terminate' ends the debugging session. Always terminate your current debugging session using 'Terminate' or 'Resume' till the end of the program. Step 5: Switching Back to Java perspective
Click the 'Java' perspective icon on the upper-right corner to switch back to the 'Java' perspective for further programming (or 'Window' menu Open Perspective Java).
Important: I can's stress more that mastering the use of debugger is crucial in programming. Explore the features provided by the debuggers. Other Debugger's Features
Step-Into and Step-Return: To debug a method , you need to use 'Step-Into' to step into the first statement of the method. ('Step-Over' runs the function in a single step without stepping through the statements within the function.) You could use 'Step-Return' to return back to the caller, anywhere within the method. Alternatively, you could set a breakpoint inside a method.
Modify the Value of a Variable: You can modify the value of a variable by entering a new value in the 'Variable' panel. This is handy for temporarily modifying the behavior of a program, without changing the source code. Tips Tricks General Usages (for all Programming Tasks)
These are the features that I find to be most useful in Eclipse:
Maximizing Window (Double-Clicking): You can double-click on the 'header' of any panel to maximize that particular panel, and double-click again to restore it back. This feature is particularly useful for writing source code in full panel.
Shorthand Templates (sysout, for,...): You can type ' sysout ' followed by a ctrl+space (or alt-/) as a shorthand for typing ' System.out.println() '.
The default shortcut key (ctrl-space or alt-/) depends on the system. Check your system's shortcut key setting in 'Edit' 'Content Assist' 'Default'. Take note that many of you use ctrl+space to switch between input languages. You need to reconfigure either your language switching hot-key or Eclipse.
Similarly, you can type 'for' followed by ctrl-space (or alt-/) to get a for-loop.
You can create your own shorthand in 'Window' menu 'Preferences' 'Java' 'Editor' 'Templates'. (Alternatively, in 'Window' 'Preferences' type 'template' as filter text and choose 'Java' 'Editor' 'Templates'.)
You can change your key settings in 'Window' menu 'Preferences' 'General' 'Key' choose 'Command', 'Content Assist'. (Alternatively, in 'Window' 'Preferences' type 'key' as filter text and choose 'General' 'Key'.)
Intelli-Sense (ctrl-space): You can use ctrl-space to activate the 'intelli-sense' (or content assist). That is, Eclipse will offer you the choices, while you are typing.
Source Formatting (ctrl-shift-f): Right-click on the source. Choose 'Source' 'Format' to let Eclipse to layout your source codes with the proper indentation.
Source Toggle Comment (ctrl-/): To comment/uncomment a block of codes, choose 'Source' 'Toggle Comment'.
Hints for Correcting Syntax Error: If there is a syntax error on a statement, a red mark will show up on the left-margin on that statement. You could click on the 'light bulb' to display the error message, and also select from the available hints for correcting that syntax error.
Refactor (or Rename) (alt-shift-r): You can rename a variable, method, class, package or even the project easily in Eclipse. Select and right-click on the entity to be renamed 'Refactor' 'Rename'. Eclipse can rename all the occurrences of the entity.
Line Numbers: To show the line numbers, choose 'Window' menu 'Preferences' 'General' 'Editors' 'Text Editors' Check the 'Show Line Numbers' Box. You can also configure many editor options, such as the number of spaces for tab. Alternatively, you can right-click on the left-margin, and check 'Show Line Numbers'.
Error Message Hyperlink: Click on an error message will hyperlink to the corresponding source statement.
Changing Font Type and Size: From 'Window' menu 'Preferences' 'General' 'Appearance' 'Colors and Fonts' expand 'Java' 'Java Editor Text Font' 'Edit'. (Alternatively, in 'Window' 'Preferences' type 'font' as filter text and choose the appropriate entry.)
Unicode Support: To enable Unicode support, select 'Window' menu Preferences General Workspace Text file encoding UTF-8. This sets the default character set used for file encoding, similar to VM's command-line option -Dfile.encoding=UTF-8 . Commonly used charsets for Unicode are UTF-8, UTF-16 (with BOM), UTF-16BE, UTF-16LE. Other charsets are US-ASCII, ISO-8859-1.
Mouse Hover-over: In debug mode, you could configure to show the variable's value when the mouse hovers over the variable. Select 'Window' menu 'Preferences' 'Java' 'Editor' 'Hover'.
Comparing Two Files: In 'Package Explorer', select two files (hold the control key) Right-click Compare with.
Useful Eclipse Shortcut Keys:
F3: Goto the declaration of the highlighted variable/method.
Ctrl-Shift-G: Search for ALL references of the highlighted variable/method in workspace.
Ctrl-G: Search for the Declaration of a variable/method in workspace.
Don't use Find (Ctrl-F), but use the above context-sensitive search.
Ctrl-Shift-F: Format the source code.
Ctrl-Shift-O: Organize imports.
Alt-Shift-R: Rename. (Don't use Find/Replace.)
Ctrl-Space: auto-complete.
Package Explorer vs. Navigator: We usually use 'Package Explorer' in programming, but it will not show you all the folders and files under the project. On the other hand, 'Navigator' is a file manager that shows the exact file structure of the project (similar to Windows Explorer). You can enable the Navigator by 'Window' Show view Navigator.
Spell Check: To enable spell check, select Window Preferences type 'spell' in the filter General Editors Text Editors Spelling Check 'Enable spell checking'. Also provide a 'User defined dictionary' (with an initially empty text file).
To correct mis-spell words, right-click and press ctrl-1 (or Edit menu Quick Fix).
Eclipse's Log File: Goto Help about Eclipse Installation details Configuration View Error Log.
Viewing two files in split screen: Simply click and hold on the title of one file and drag it to the lower side of the screen. [To view the same file on split screen, create a new editor window by selecting Window New Editor; and drag one window to the lower side of the screen.]
Block Select (Column Select): Push Alt-Shift-A to toggle between block-select mode and normal mode.
Snippets:
To view the snippet window: choose 'Window' Show View Snippets.
To create a new snippet category: Right-click Customize New.
To create a new snippet item: Copy the desired text Select the snippet category paste as snippet.
To insert a snippet: place the cursor on the desired location at the editor panel click the snippet item.
Word Wrap (Line Wrap): Word-wrap (or line-wrap) is essential for editing long HTML documents without the horizontal scroll bar. However, the Eclipse's HTML Editor and Text Editor do not support word-wrap.
You could install a plug-in called 'Word Wrap' from http://ahtik.com/eclipse-update/.
Choose 'Help' Install New Software in 'Work with' Enter 'http://ahtik.com/eclipse-update/'.
To activate word wrap, right-click on the editor panel select 'Word Wrap'.
Creating 'link folder' in project : You do not have to place all the folders under the project base directory, instead, you can use so-called 'link folders' to link to folder outside the project base directory.
To create a link folder in a project, right-click on the project File New Folder Advanced Check Link to alternate Location (Linked Folder).
Running Eclipse in 'clean' mode: You can run eclipse in so-called ' clean ' mode, which wipes all the cached data and re-initialize the cache, by running eclipse from command-line with '-clean' argument (i.e., ' eclipse -clean '). It is useful if something is not working proper, especially if you install a new copy of Eclipse.
Show the Right Margin: Window Preferences General Editors Text Editors Show Print Margin and set the column number.
Let me know if you have more tips to be included here. Update Eclipse and Install new Software
Install New Software: Select 'Help' menu Install New Software In 'Work With', pull down the select menu and choose a software site.
Update: Select 'Help' menu Check for Updates . For Java Application Development Only
Small Toy Java Programs: You can keep many small programs (with main() ) in one Java project instead of create a new project for each toy program. To run the desired program, right-click on the source file 'Run as' 'Java Application'.
Scanner/printf() and JDK 1.5: If you encounter syntax error in using printf() or Scanner (which are available from JDK 1.5), you need to check your compiler settings. Select 'Window' menu Preferences open the 'Java' node select 'Compiler' in 'Compiler compliance level' select the latest release, which should be '1.5' or above.
Command-Line Arguments: To provide command-line arguments to your Java program in Eclipse, right-click on the source file 'Run Configurations' Under the 'Main' panel, check that 'Project' name and 'Main Class' are appropriate Select the 'Argument' tab type your command-line arguments inside the 'Program Arguments' box 'Run'.
Resolving Import (Ctrl-Shift-o) : To ask Eclipse to insert the import statements for classes. Useful when you copy a large chunk of codes without the corresponding import statements.
Including Another Project: To include another project in the same work space, right-click on the project Build Path Configure Build Path... Select 'Projects' tab 'Add...' to select project in the existing work space OK.
Exporting a Project to a JAR file: Right-click on the project Export... Java, JAR File Next Select the files to be exported Next Next In 'JAR Manifest Specification' dialog, enter the main class (if you wish to run the JAR file directly) Finish.
Unit Testing: If you keep your test in another project, you need to include the project under test in your Build Path (see above).
To create a test case: Right-click on the project New JUnit Test Case the 'New JUnit Test Case' dialog appears. Select 'New JUnit 4 Test'. In 'Name', enter your class name. In 'Class under test', browse and select the class to be tested.
To run the test: Right-click 'Run As' 'JUnit Test'. The results are displayed in a special 'JUnit console'.
Adding External JAR files Native Libraries (' .dll ', ' .lib ', ' .a ', ' .so '): Many external Java packages (such as JOGL, Java3D, JAMA, etc) are available to extend the functions of JDK. These packages typically provide a ' lib ' directory containing JAR files (' .jar ') (Java Archive - a single-file package of Java classes) and native libraries (' .dll ', ' .lib ' for windows, ' .a ', ' .so ' for Linux and macOS).
To include these external packages into an Eclipse's project, right-click on the project Build Path Add External Archives Navigate to select the JAR files (' .jar ') to be included.
In 'Package Explorer', right-click on the JAR file added Properties:
To include native libraries (' .dll ', ' .lib ', ' .a ', ' .so '), select 'Native Library' 'Location Path' 'External Folder'.
To include the javadoc, select 'JavaDoc Location' 'JavaDoc URL' You can specify a local file or a remote link.
To include source file (for debugging), select 'Java Source Attachment'. All the above options are also accessible via project's property 'Build Path'.
Notes: The JAR files must be included in the CLASSPATH . The native library directories must be included in JRE's property ' java.library.path ', which normally but not necessarily includes all the paths from the PATH environment variable. Read 'External JAR files and Native Libraries'.
Creating a User Library: You can also create a Eclipse's user library to include a set of JAR files and native libraries, that can then be added into subsequent Eclipse projects.
For example, I created a user library for 'JOGL' as follows:
From 'Window' menu Preferences Java Build Path User Libraries New In 'User library name', enter ' jogl '. The 'User Library' dialog appears.
In 'User Library' dialog Select ' jogl ' Add JAR... Navigate to JOGL_HOME/lib , and select ' gluegen-rt.jar ' and ' jogl.jar '.
Expand the ' jogl.jar ' node Select 'Native library location: (none)' Edit... External Folder... select JOGL_HOME/lib .
Expand the ' jogl.jar ' node Select 'Javadoc location: (none) ' Edit... Javadoc in archive In 'Archive Path', 'Browse' and select the downloaded JOGL API documentation zip-file In 'Path within archive', 'Browse' and expand the zip-file to select the top-level path (if any) Validate. Alternatively, you can provide the path to the un-zipped javadocs. This is needed for Eclipse to display javadoc information about classes, fields, and methods.
You may provide the source files by editing 'Source attachment: (none)'. Source is needed only if you are interested to debug into the JOGL source codes. For EACH subsequent Java project created that uses JOGL, right-click on the project Build Path Add Libraries Select 'User Library' Check ' jogl '.
Running an External Program: Suppose that you want to run a Perl script on the selected file, you can configure an external tool as follows:
From 'Run' menu External Tools External Tools Configuration... The 'External Tools Configuration' dialog appears.
In 'Name', enter your tool name.
Choose the 'Main' tab In 'Location', 'Browse File System...' to choose the perl interpreter 'perl' In 'Arguments', enter ' path/scriptname.pl $resource_loc ', where $resource_loc is an Eclipse variable that denotes the currently selected resource with absolute path.
Choose the 'Common' tab In 'Standard Input and Output', uncheck 'Allocate Console', check 'File' and provide an output file (e.g., d:temp$resource_name.txt ).
(If you use the CYGWIN perl interpreter, need to set environment variable CYGWIN=nodosfilewarning to disable warning message.) To run the configured external tool, select a file run external tool tool name.
Viewing Hex Code of Primitive Variables in Debug mode: In debug perspective, 'Variable' panel Select the 'menu' (inverted triangle) Java Java Preferences... Primitive Display Options Check 'Display hexadecimal values (byte, short, char, int, long)'.
Adding a New Version of JDK/JRE: First, you can check the installed JDK/JRE via 'Window' menu 'Preferences' Expand 'Java' node 'Installed JREs'. Check the 'Location' current JRE installed to make sure that it is the intended one. You can use the 'Add' button to add a new version of JRE. For program development, I recommend that you add the JDK (instead of JRE). [The 'Location' decides the extension directory used for including additional JAR files, e.g., $JAVA_HOMEjrelibext .] For Web Developers
HTML Editor: Use the 'Web Page Editor' (available in Eclipse Java EE), which provides the design view (WYSISYG).
To use the 'Web Page Editor', right-click on the HTML file, open as 'Web Page Editor'.
To make the 'Web Page Editor' as default for HTML file, goto Window Preferenes General Editor File Associations .htm and .html Select 'Web page editor' default. File I/O in Eclipse
Suppose that your want to write a Java program, which inputs from a text file called ' xxxx.in ' and outputs to a text file called ' xxxx.out '. This is a little tricky under Eclipse due to:
When you create a text file in Windows' Notepad and saved it as ' xxxx.in ', Notepad will append the ' .txt ' to your file and it becomes ' xxxx.in.txt '. Worse still, the Windows' Explorer, by default, will not show the ' .txt ' extension. (The first thing I always do to an alien computer is to change this setting. From 'Tools' menu Folder Options... View Uncheck 'Hide extensions for known file types'.) You need to put a pair of double quotes around xxxx.in to override the default ' .txt ' extension. This is one good reason not to use Notepad for programming at all. You should use Eclipse to create the text file instead.
Which directory to keep the input file ' xxxx.in ' in Eclipse?
If you did not separate the sources and class files into two separate directories, then the answer is straight forward, because there is only one directory to place your input file.
If you choose to keep your sources and class files in two separate directories, eclipse will create two sub-directories 'src' and 'bin' under the base directory. BUT you need to put your input file ' xxxx.in ' in the base directory of your project, instead of the 'src' or 'bin'.. For writing simple programs:
Put the sources, class files, and the input/output files in the same directory. (When you create a new project, select 'Use project folder as root for sources and class files' in 'Project Layout'.) (But put your sources and class files in separate directories for big project.)
You can create you input file from eclipse directly via 'File' menu 'New' 'File'.
Remember to add a newline to the end of your input file.
You may need to right-click the project and select 'Refresh' to see the output file ' xxxx.out ' created in the package explorer.
To open the ' xxxx.in ' and ' xxxx.out ': right-click Open With Text Editor.
This is a sample JDK 1.5 program for file input/output:
Create the input text file called ' FileIOTest.in ' with the following contents and terminated with a newline: Writing Swing Applications using Eclipse GUI Builder
Eclipse provides a visual GUI builder called 'WindowBuilder' (@ https://www.eclipse.org/windowbuilder), which supports AWT/Swing, SWT (Eclipse's Standard Widget Toolkit - an alternative to JDK's AWT/Swing), XWT, GWT, eRCT. Step 0: Install WindowBuilder
To install 'WindowBuilder', goto 'Help' Install New Software In 'Work with', enter 'https://download.eclipse.org/windowbuilder/latest/' (You can find the proper link from 'http://www.eclipse.org/windowbuilder/download.php') Check 'WindowBuilder' Next Next Accept the licence Finish. Step 1: Create a New 'Java Application' Project
Choose 'File' menu 'New' 'Java project'.
The 'New Java Project' dialog pops up.
In the 'Project name' field, enter ' FirstSwingProject '.
Check 'Use default location'.
In the 'JRE' box, select 'Use default JRE (currently 'JDK1.x')'.
Click 'Finish'. Step 2: Create a Swing JFrame Subclass
Choose 'File' menu 'New' 'Others' 'WindowBuilder' 'Swing Designer' 'JFrame' 'Next'.
In the 'Create JFrame' dialog Enter 'SwingMain' in the 'Name' field 'Finish'.
Select the 'Design' pane.
In 'Layouts', select 'FlowLayout' and click on the 'design form'.
From 'Components', select ' JLabel ' and click on the design form. Change the label text to 'Counter: '. Select a 'JTextField' and place it on the design form. Change the text to '0'. Select a 'JButton' and place it on the design form. Change the text label to 'Count'.
To attach a event-handler to the button, double-click the JButton to switch into the 'Source' pane, with the event-handler skeleton created. Complete the actionPerformed() as follows: Add an instance variable called count as follow:
You can now ready run the program. Right-click on the project Run As Java Application. Eclipse Generated Codes
Study the codes generated by Eclipse GUI Builder, as follows, which is just a typical Swing application. Eclipse for C/C++ Programming
Here. Eclipse PDT (PHP Development Tool)
Here. Eclipse and Database Development (MySQL)
Reference: 'Data Tools Platform User Documentation' @ Eclipse Welcome page.
You need to install Eclipse for Java EE, MySQL and MySQL Connector/J Driver. Read 'How to install and get started with MySQL'.
To use Eclipse for MySQL development:
Switch to 'Database Development' perspective: From 'Window' menu Open Perspective Other Database Development.
Connect to MySQL database server: Start your MySQL database server. Right-click 'Database Connection' New.
In 'Connection Profile', choose 'MySQL' Next.
In 'Driver', choose 'New Driver Definition' Choose the MySQL Connector/J Driver In JAR List, select the MySQL Connector/J Driver JAR file (that you have installed). In 'Properties', 'General', specify URL (take note of the database name), User name and password Test Connection Finish.
In 'Datasource Explorer', you can 'connect' and 'disconnect' the connection.
To create a new SQL script, choose File New SQL File You may use an existing project or create a new project (General - Project or Web - Dynamic Web Project) Enter filename, and set the connection profile name Finish. Enter a SQL statement (e.g., SELECT * FROM tablename) Right-click on the text 'Execute Current Text' or 'Execute All'.
To use an existing SQL file, drop the file into a project and open the SQL file. In Connection profile, set the type and connection name. Right-click on a statement 'Execute ...'.
To CURD (create-update-read-delete) tables, in 'Datasource Explorer' (of the 'Database Development' perspective), expand 'database' to view the tables. Right-right on the table Datat Edit. Developing and Deploying Web Applications in Eclipse for Java EE Setting Up Eclipse for Web Development
Install 'Eclipse for Java EE (Enterprise Edition)'.
Install Tomcat (or Glassfish) server.
Configuring Web Server: Launch Eclipse Window Preferences Expand the 'Server' node 'Runtime Environments' 'Add...' Expand 'Apache' and select 'Apache Tomcat v7.0' Enter the 'Tomcat Installation Directory' 'Finish'. Writing a Hello-world JSP Page
Create a new Web Application: File New Dynamic Web Project (under 'Web' category) In 'Project Name', enter ' HelloJSP ' Finish.
Create a new JSP File: Right-click on the project ' HelloJSP ' New JSP File The parent folder shall be 'HelloJSP/WebContent' In 'File Name', enter ' Hello ' 'Finsih'.
Enter the following HTML/JSP codes within the body.../body tags:
To execute the JSP, right-click on ' Hello.jsp ' Run As Run on Server. Writing a Hello-world Servlet
Create a new Web Application: File New Dynamic Web Project (under 'Web' category) In 'Project Name', enter ' HelloServlet ' 'Finish'.
Create a new Servlet: Right-click on the project ' HelloServlet ' New Servlet In 'Java Package', enter ' hello '; in 'Class Name', enter ' HelloServlet ' Next In 'URL Mappings', select ' HelloServlet ', 'Edit' to ' Hello ' Next In 'Which method stubs would you like to create', check 'Inherited abstract method' and 'doGet' Finish.
In 'HelloServlet.java', enter the following codes:
(For Servlet 2.4/2.5 with Tomcat 6) The annotation @WebServlet is new in Servlet 3.0 and is not supported in Servlet 2.4/2.5. Hence, you need to manually configure the URL for the servlet in the Web Application Deployment Descriptor ' web.xml ' under directory ' WEB-INF ', as follows:
To execute the Servlet, right-click on the ' HelloServlet ' project 'Run As' 'Run on Server' Change the URL to ' http://localhost:8080/HelloServlet/sayhello '. Exporting a Web Application as a WAR file
Right-click on the project to be exported Export WAR File In 'Destination', specify the destination directory and filename (the filename shall be the web application name) Finish.
To deploy the war file in Tomcat, simply drop the war file into Tomcat's ' webapps ' folder. The war file will be automatically extracted and deployed. The web application name is the war-filename.
You could use WinZip (or WinRAR) to view the content of the war file, as war-file is in ZIP format. Writing a Hello-world JSF Page
[TODO] Debugging Web Applications
You can debug a webapp just like standalone application. For example, you can set breakpoints, single-step through the programs, etc.
REFERENCES RESOURCES
Eclipse mother site @ https://www.eclipse.org.
Eclipse documentation and user guides, accessible via Eclipse's Help and menu. Eclipse IDE for Java EE Developers
276 MB
2,354,758 DOWNLOADS
Tools for Java developers creating Java EE and Web applications, including a Java IDE, tools for Java EE, JPA, JSF, Mylyn, EGit and others. Eclipse IDE for Java Developers
167 MB
1,188,937 DOWNLOADS
The essential tools for any Java developer, including a Java IDE, a Git client, XML Editor, Mylyn, Maven integration and WindowBuilder Eclipse IDE for C/C++ Developers
177 MB
339,297 DOWNLOADS
An IDE for C/C++ developers with Mylyn integration. Eclipse for PHP Developers
154 MB
161,709 DOWNLOADS
The essential tools for any PHP developer, including PHP language support, Git client, Mylyn and editors for JavaScript, HTML, CSS and XML. Eclipse IDE for Eclipse Committers 4.5.2 Download Java Ee Eclipse For Mac Os
245 MB
142,584 DOWNLOADS
Package suited for development of Eclipse itself at Eclipse.org; based on the Eclipse Platform adding PDE, Git, Marketplace Client, source code and developer documentation.
Click here to file a bug against Eclipse Platform.
Click here to file a bug against Eclipse Git team provider. Eclipse for RCP and RAP Developers
259 MB
84,055 DOWNLOADS
A complete set of tools for developers who want to create Eclipse plug-ins, Rich Client Applications or Remote Application Platform (RCP+RAP), plus Mylyn, the m2e Maven integration, and an XML editor. It contains the EGit tooling for accessing Git version control systems. Eclipse IDE for Java and DSL Developers
300 MB
55,321 DOWNLOADS
The essential tools for Java and DSL developers, including a Java Xtend IDE, a DSL Framework (Xtext), a Git client, XML Editor, and Maven integration. Eclipse Modeling Tools
370 MB
27,127 DOWNLOADS
The Modeling package provides tools and runtimes for building model-based applications. You can use it to graphically design domain models, to leverage those models at design time by creating and editing dynamic instances, to collaborate via Eclipse's team support with facilities for comparing and merging models and model instances structurally, and finally to generate Java code from those models to produce complete applications. In addition, via the package's discover catalog, you can easily install a wide range of additional powerful, model-based tools and runtimes to suit your specific needs. Eclipse IDE for Java and Report Developers
301 MB
20,821 DOWNLOADS
Java EE tools and BIRT reporting tool for Java developers to create Java EE and Web applications that also have reporting needs. Eclipse for Parallel Application Developers
222 MB
9,115 DOWNLOADS
Tools for C, C++, Fortran, and UPC, including MPI, OpenMP, OpenACC, a parallel debugger, and remotely building, running and monitoring applications. Eclipse for Scout Developers
314 MB
8,987 DOWNLOADS
Eclipse Scout is a framework to develop Java/Eclipse based business applications that run on the desktop, in browsers, and on mobile devices. This package includes a complete SDK, useful developer tools and source code. Download Eclipse Java Ee For Mac Eclipse for Testers
118 MB
8,180 DOWNLOADS Download Java Ee Eclipse For Mac 64-bit
This package contains Eclipse features that support the software development quality assurance process, such as Jubula and Mylyn.
Eclipse (@ www.eclipse.org) is an open-source Integrated Development Environment (IDE) supported by IBM. Eclipse is popular for Java application development (Java SE and Java EE) and Android apps. It also supports C/C++, PHP, Python, Perl, and other web project developments via extensible plug-ins. Eclipse is cross-platform and runs under Windows, Linux and macOS. Eclipse Versions
The various versions are:
Eclipse 1.0 (November 7, 2001): based on an earlier Java IDE called VisualAge from IBM.
Eclipse 2.0 (June 28, 2002)
Eclipse 2.1 (March 28, 2003)
Eclipse 3.0 (June 25, 2004)
Eclipse 3.1 (June 28, 2005)
Eclipse 3.2 (June 30, 2006) (Callisto - named after one of the Jupiter's Galilean moons): started annual simultaneous release of all the related Eclipse projects.
Eclipse 3.3 (June 25, 2007) (Europa - named after another Jupiter's Galilean moons)
Eclipse 3.4 (June 19, 2008) (Ganymede - named after yet another Jupiter's Galilean moons)
Eclipse 3.5 (June 12, 2009) (Galileo - named after the great 17th century scientist and astronomer Galileo Galilei)
Eclipse 3.6 (June 23, 2010) (Helios - named after god of the sun in Greek Mythology)
Eclipse 3.7 (June 23, 2011) (Indigo)
Eclipse 4.2 (June 27, 2012) (Juno)
Eclipse 4.3 (June 2013) (Kepler)
Eclipse 4.4 (June 2014) (Luna)
Eclipse 4.5 (June 2015) (Mars)
Eclipse 4.6 (June 2016) (Neon)
Eclipse 4.7 (June 2017) (Oxygen)
Eclipse 4.8 (June 2018) (Photon)
Eclipse 2018-09 (4.9)
Eclipse 2018-12 (4.10)
Eclipse 2019-03 (4.11)
Eclipse 2019-06 (4.12)
Eclipse 2019-09 (4.13)
Eclipse 2019-12 (4.14) How to Install Eclipse IDE 2019-12 for Java Developers How to Install Eclipse on Windows Step 0: Install JDK
To use Eclipse for Java programming, you need to first install Java Development Kit (JDK). Read 'How to Install JDK for Windows'. Step 1: Download
Download Eclipse from https://www.eclipse.org/downloads. Under 'Get Eclipse IDE 2019-12' Click 'Download Packages'. For beginners, choose the ' Eclipse IDE for Java Developers ' and ' Windows 64-bit ' (e.g., ' eclipse-java-2019-12-R-win32-x86_64.zip ' - about 201MB) Download. Step 2: Unzip
To install Eclipse, simply unzip the downloaded file into a directory of your choice (e.g., ' c:myProject ').
I prefer the zip version, because there is no need to run any installer. Moreover, you can simply delete the entire Eclipse directory when it is no longer needed (without running any un-installer). You are free to move or rename the directory. You can install (unzip) multiple copies of Eclipse in the same machine. How to Install Eclipse on macOS
To use Eclipse for Java programming, you need to first install JDK. Read 'How to install JDK for macOS'.
To install Eclipse:
Goto http://www.eclipse.org/downloads/. Under 'Get Eclipse IDE 2019-12' Click 'Download Packages'. For beginners, select ' Eclipse IDE for Java Developers ' and ' Mac Cocoa 64-bit '. You will receive a DMG file (e.g., ' eclipse-java-2019-12-R-macosx-cocoa-x86_64.dmg ').
Double-click the downloaded Disk Image (DMG) file. Follow the screen instructions to install Eclipse. Eclipse will be installed under ' /Applications/eclipse '. (To confirm!) How to Install Eclipse on Ubuntu Linux
Eclipse comes with many flavors (See 'Eclipse Packages' @ https://www.eclipse.org/downloads/compare.php):
To use Eclipse for Java programming, choose 'Eclipse IDE for Java Developers' (JavaSE) or 'Eclipse IDE for Java EE Developers' (JavaEE). You need to first install JDK. Read 'How to install JDK on Ubuntu'.
To use Eclipse for PHP programming, choose 'Eclipse IDE for PHP Developers'.
To use Eclipse for C/C++ programming, choose 'Eclipse IDE for C/C++ Developers'.
Nonetheless, you can install any package, and then add more features when needed.
To install Eclipse (e.g, for Java Programming):
Download Eclipse from http://www.eclipse.org/downloads/. Under 'Get Eclipse IDE 2019-12' Click 'Download Packages'. Choose 'Eclipse IDE for Java Developers' for Java SE program development; or 'Eclipse IDE for Java EE Developers' for developing webapps Linux 64-bit. You will receive a tarball (e.g., ' eclipse-java-2019-12-R-linux-gtk-x86_64.tar.gz ') in the ' /Downloads ' folder.
We shall install Eclipse under /usr/local .
To run Eclipse, open the ' /usr/local/eclipse ' folder and click on the 'Eclipse' icon; or start a 'Terminal', enter 'eclipse'. Lock Eclipse on Launcher
Simply start Eclipse. Right-click the Eclipse icon Lock to Launcher.
(For older version - If the above don't work) Create a /usr/share/applications/eclipse.desktop file with the following contents:
Start Eclipse, right-click on the Eclipse icon on launcher lock to launcher. Writing your First Java Program in Eclipse Step 0: Launch Eclipse
Launch Eclipse by running ' eclipse.exe ' from the Eclipse installed directory.
Choose an appropriate directory for your workspace , i.e., where you would like to save your files (e.g., c:myProjecteclipse for Windows) Launch.
If the 'Welcome' screen shows up, close it by clicking the 'close' button next to the 'Welcome' title. Step 1: Create a new Java Project For each Java application, you need to create a project to keep all the source files, classes and relevant resources.
To create a new Java project:
Choose 'File' menu 'New' 'Java project' (or 'File' 'New' 'Project' 'Java project').
The 'New Java Project' dialog pops up.
In 'Project name', enter ' FirstProject '.
Check 'Use default location'.
In 'JRE', select 'Use default JRE (currently 'JDK11.0.x')'. But make sure that your JDK is 1.8 and above.
In 'Project Layout', check 'Use project folder as root for sources and class files'. Push ' Finish ' button.
In 'Create module-info.java' dialog, Click 'Don't Create' . (Note: For easier version of Eclipse, you need to use the 'Next' Button in the previous step, and uncheck 'Create module-info.java file'). Step 2: Write a Hello-world Java Program
In the 'Package Explorer' (left pane) Right-click on ' FirstProject ' (or use the 'File' menu) New Class.
The 'New Java Class' dialog pops up.
In 'Source folder', keep the 'FirstProject'.
In 'Package', delete the content if it is not empty.
In 'Name', enter ' Hello '.
Check ' public static void main(String[] args) '.
Don't change the rest. Push 'Finish' button.
The source file ' Hello.java ' opens on the editor panel (the center pane). Enter the following codes: Step 3: Compile Execute the Java Program
There is no need to compile the Java source file in Eclipse explicitly. It is because Eclipse performs the so-called incremental compilation , i.e., the Java statement is compiled as and when it is entered.
To run the program, right-click anywhere on the source file ' Hello.java ' (or choose 'Run' menu) Run As Java Application.
The output 'Hello, world!' appears on the Console panel (the bottom pane). NOTES:
You should create a NEW Java project for EACH of your Java application.
Nonetheless, Eclipse allows you to keep more than one programs in a project, which is handy for writing toy programs (such as your tutorial exercises). To run a particular program, open and right-click on the source file Run As Java Application.
Clicking the 'Run' button (with a 'Play' icon) runs the recently-run program (based on the previous configuration). Try clicking on the 'down-arrow' besides the 'Run' button. Correcting Syntax Errors
Eclipse performs incremented compilation, as and when a source 'line' is entered. It marked a source line having syntax error with a RED CROSS. Place your cursor at the RED CROSS to view the error message.
You CANNOT RUN the program if there is any syntax error (marked by a RED CROSS before the filename). Correct all the syntax errors; and RUN the program.
HINTS: In some cases, Eclipse shows a ORANGE LIGHT-BULB (for HINTS) next to the ERROR RED-CROSS (Line 5 in the above diagram). You can click on the LIGHT-BULB to get a list of HINTS to resolve this particular error, which may or may not work!
SYNTAX WARNING: marked by a orange triangular exclaimation sign. Unlike errors, warnings may or may not cause problems. Try to fix these warnings as well. But you can RUN your program with warnings. Read the Eclipse Documentation
At a minimum, you SHOULD browse through Eclipse's ' Workbench User Guide ' and ' Java Development User Guide ' - accessible via the Eclipse's 'Welcome' page or 'Help' menu. This will save you many agonizing hours trying to figure out how to do somethings later. Debugging Programs in Eclipse
Able to use a graphics debugger to debug program is crucial in programming. It could save you countless hours guessing on what went wrong. Step 0: Write a Java Program
The following program computes and prints the factorial of n ( =1*2*3*...* n ). The program, however, has a logical error and produce a wrong answer for n =20 (' The Factorial of 20 is -2102132736 ' - a negative number?!).
Let's use the graphic debugger to debug the program. Step 1: Set an Initial Breakpoint
A breakpoint suspends program execution for you to examine the internal states (e.g., value of variables) of the program. Before starting the debugger, you need to set at least one breakpoint to suspend the execution inside the program. Set a breakpoint at main() method by double-clicking on the left-margin of the line containing main() . A blue circle appears in the left-margin indicating a breakpoint is set at that line. Step 2: Start Debugger
Right click anywhere on the source code (or from the 'Run' menu) 'Debug As' 'Java Application' choose 'Yes' to switch into 'Debug' perspective (A perspective is a particular arrangement of panels to suits a certain development task such as editing or debugging). The program begins execution but suspends its operation at the breakpoint, i.e., the main() method.
As illustrated in the following diagram, the highlighted line (also pointed to by a blue arrow) indicates the statement to be executed in the next step. Step 3: Step-Over and Watch the Variables and Outputs
Click the 'Step Over' button (or select 'Step Over' from 'Run' menu) to single-step thru your program. At each of the step, examine the value of the variables (in the 'Variable' panel) and the outputs produced by your program (in the 'Console' Panel), if any. You can also place your cursor at any variable to inspect the content of the variable.
Single-stepping thru the program and watching the values of internal variables and the outputs produced is the ultimate mean in debugging programs - because it is exactly how the computer runs your program! Step 4: Breakpoint, Run-To-Line, Resume and Terminate
As mentioned, a breakpoint suspends program execution and let you examine the internal states of the program. To set a breakpoint on a particular statement, double-click the left-margin of that line (or select 'Toggle Breakpoint' from 'Run' menu).
'Resume' continues the program execution, up to the next breakpoint, or till the end of the program.
'Single-step' thru a loop with a large count is time-consuming. You could set a breakpoint at the statement immediately outside the loop (e.g., Line 11 of the above program), and issue 'Resume' to complete the loop.
Alternatively, you can place the cursor on a particular statement, and issue 'Run-To-Line' from the 'Run' menu to continue execution up to the line.
'Terminate' ends the debugging session. Always terminate your current debugging session using 'Terminate' or 'Resume' till the end of the program. Step 5: Switching Back to Java perspective
Click the 'Java' perspective icon on the upper-right corner to switch back to the 'Java' perspective for further programming (or 'Window' menu Open Perspective Java).
Important: I can's stress more that mastering the use of debugger is crucial in programming. Explore the features provided by the debuggers. Other Debugger's Features
Step-Into and Step-Return: To debug a method , you need to use 'Step-Into' to step into the first statement of the method. ('Step-Over' runs the function in a single step without stepping through the statements within the function.) You could use 'Step-Return' to return back to the caller, anywhere within the method. Alternatively, you could set a breakpoint inside a method.
Modify the Value of a Variable: You can modify the value of a variable by entering a new value in the 'Variable' panel. This is handy for temporarily modifying the behavior of a program, without changing the source code. Tips Tricks General Usages (for all Programming Tasks)
These are the features that I find to be most useful in Eclipse:
Maximizing Window (Double-Clicking): You can double-click on the 'header' of any panel to maximize that particular panel, and double-click again to restore it back. This feature is particularly useful for writing source code in full panel.
Shorthand Templates (sysout, for,...): You can type ' sysout ' followed by a ctrl+space (or alt-/) as a shorthand for typing ' System.out.println() '.
The default shortcut key (ctrl-space or alt-/) depends on the system. Check your system's shortcut key setting in 'Edit' 'Content Assist' 'Default'. Take note that many of you use ctrl+space to switch between input languages. You need to reconfigure either your language switching hot-key or Eclipse.
Similarly, you can type 'for' followed by ctrl-space (or alt-/) to get a for-loop.
You can create your own shorthand in 'Window' menu 'Preferences' 'Java' 'Editor' 'Templates'. (Alternatively, in 'Window' 'Preferences' type 'template' as filter text and choose 'Java' 'Editor' 'Templates'.)
You can change your key settings in 'Window' menu 'Preferences' 'General' 'Key' choose 'Command', 'Content Assist'. (Alternatively, in 'Window' 'Preferences' type 'key' as filter text and choose 'General' 'Key'.)
Intelli-Sense (ctrl-space): You can use ctrl-space to activate the 'intelli-sense' (or content assist). That is, Eclipse will offer you the choices, while you are typing.
Source Formatting (ctrl-shift-f): Right-click on the source. Choose 'Source' 'Format' to let Eclipse to layout your source codes with the proper indentation.
Source Toggle Comment (ctrl-/): To comment/uncomment a block of codes, choose 'Source' 'Toggle Comment'.
Hints for Correcting Syntax Error: If there is a syntax error on a statement, a red mark will show up on the left-margin on that statement. You could click on the 'light bulb' to display the error message, and also select from the available hints for correcting that syntax error.
Refactor (or Rename) (alt-shift-r): You can rename a variable, method, class, package or even the project easily in Eclipse. Select and right-click on the entity to be renamed 'Refactor' 'Rename'. Eclipse can rename all the occurrences of the entity.
Line Numbers: To show the line numbers, choose 'Window' menu 'Preferences' 'General' 'Editors' 'Text Editors' Check the 'Show Line Numbers' Box. You can also configure many editor options, such as the number of spaces for tab. Alternatively, you can right-click on the left-margin, and check 'Show Line Numbers'.
Error Message Hyperlink: Click on an error message will hyperlink to the corresponding source statement.
Changing Font Type and Size: From 'Window' menu 'Preferences' 'General' 'Appearance' 'Colors and Fonts' expand 'Java' 'Java Editor Text Font' 'Edit'. (Alternatively, in 'Window' 'Preferences' type 'font' as filter text and choose the appropriate entry.)
Unicode Support: To enable Unicode support, select 'Window' menu Preferences General Workspace Text file encoding UTF-8. This sets the default character set used for file encoding, similar to VM's command-line option -Dfile.encoding=UTF-8 . Commonly used charsets for Unicode are UTF-8, UTF-16 (with BOM), UTF-16BE, UTF-16LE. Other charsets are US-ASCII, ISO-8859-1.
Mouse Hover-over: In debug mode, you could configure to show the variable's value when the mouse hovers over the variable. Select 'Window' menu 'Preferences' 'Java' 'Editor' 'Hover'.
Comparing Two Files: In 'Package Explorer', select two files (hold the control key) Right-click Compare with.
Useful Eclipse Shortcut Keys:
F3: Goto the declaration of the highlighted variable/method.
Ctrl-Shift-G: Search for ALL references of the highlighted variable/method in workspace.
Ctrl-G: Search for the Declaration of a variable/method in workspace.
Don't use Find (Ctrl-F), but use the above context-sensitive search.
Ctrl-Shift-F: Format the source code.
Ctrl-Shift-O: Organize imports.
Alt-Shift-R: Rename. (Don't use Find/Replace.)
Ctrl-Space: auto-complete.
Package Explorer vs. Navigator: We usually use 'Package Explorer' in programming, but it will not show you all the folders and files under the project. On the other hand, 'Navigator' is a file manager that shows the exact file structure of the project (similar to Windows Explorer). You can enable the Navigator by 'Window' Show view Navigator.
Spell Check: To enable spell check, select Window Preferences type 'spell' in the filter General Editors Text Editors Spelling Check 'Enable spell checking'. Also provide a 'User defined dictionary' (with an initially empty text file).
To correct mis-spell words, right-click and press ctrl-1 (or Edit menu Quick Fix).
Eclipse's Log File: Goto Help about Eclipse Installation details Configuration View Error Log.
Viewing two files in split screen: Simply click and hold on the title of one file and drag it to the lower side of the screen. [To view the same file on split screen, create a new editor window by selecting Window New Editor; and drag one window to the lower side of the screen.]
Block Select (Column Select): Push Alt-Shift-A to toggle between block-select mode and normal mode.
Snippets:
To view the snippet window: choose 'Window' Show View Snippets.
To create a new snippet category: Right-click Customize New.
To create a new snippet item: Copy the desired text Select the snippet category paste as snippet.
To insert a snippet: place the cursor on the desired location at the editor panel click the snippet item.
Word Wrap (Line Wrap): Word-wrap (or line-wrap) is essential for editing long HTML documents without the horizontal scroll bar. However, the Eclipse's HTML Editor and Text Editor do not support word-wrap.
You could install a plug-in called 'Word Wrap' from http://ahtik.com/eclipse-update/.
Choose 'Help' Install New Software in 'Work with' Enter 'http://ahtik.com/eclipse-update/'.
To activate word wrap, right-click on the editor panel select 'Word Wrap'.
Creating 'link folder' in project : You do not have to place all the folders under the project base directory, instead, you can use so-called 'link folders' to link to folder outside the project base directory.
To create a link folder in a project, right-click on the project File New Folder Advanced Check Link to alternate Location (Linked Folder).
Running Eclipse in 'clean' mode: You can run eclipse in so-called ' clean ' mode, which wipes all the cached data and re-initialize the cache, by running eclipse from command-line with '-clean' argument (i.e., ' eclipse -clean '). It is useful if something is not working proper, especially if you install a new copy of Eclipse.
Show the Right Margin: Window Preferences General Editors Text Editors Show Print Margin and set the column number.
Let me know if you have more tips to be included here. Update Eclipse and Install new Software
Install New Software: Select 'Help' menu Install New Software In 'Work With', pull down the select menu and choose a software site.
Update: Select 'Help' menu Check for Updates . For Java Application Development Only
Small Toy Java Programs: You can keep many small programs (with main() ) in one Java project instead of create a new project for each toy program. To run the desired program, right-click on the source file 'Run as' 'Java Application'.
Scanner/printf() and JDK 1.5: If you encounter syntax error in using printf() or Scanner (which are available from JDK 1.5), you need to check your compiler settings. Select 'Window' menu Preferences open the 'Java' node select 'Compiler' in 'Compiler compliance level' select the latest release, which should be '1.5' or above.
Command-Line Arguments: To provide command-line arguments to your Java program in Eclipse, right-click on the source file 'Run Configurations' Under the 'Main' panel, check that 'Project' name and 'Main Class' are appropriate Select the 'Argument' tab type your command-line arguments inside the 'Program Arguments' box 'Run'.
Resolving Import (Ctrl-Shift-o) : To ask Eclipse to insert the import statements for classes. Useful when you copy a large chunk of codes without the corresponding import statements.
Including Another Project: To include another project in the same work space, right-click on the project Build Path Configure Build Path... Select 'Projects' tab 'Add...' to select project in the existing work space OK.
Exporting a Project to a JAR file: Right-click on the project Export... Java, JAR File Next Select the files to be exported Next Next In 'JAR Manifest Specification' dialog, enter the main class (if you wish to run the JAR file directly) Finish.
Unit Testing: If you keep your test in another project, you need to include the project under test in your Build Path (see above).
To create a test case: Right-click on the project New JUnit Test Case the 'New JUnit Test Case' dialog appears. Select 'New JUnit 4 Test'. In 'Name', enter your class name. In 'Class under test', browse and select the class to be tested.
To run the test: Right-click 'Run As' 'JUnit Test'. The results are displayed in a special 'JUnit console'.
Adding External JAR files Native Libraries (' .dll ', ' .lib ', ' .a ', ' .so '): Many external Java packages (such as JOGL, Java3D, JAMA, etc) are available to extend the functions of JDK. These packages typically provide a ' lib ' directory containing JAR files (' .jar ') (Java Archive - a single-file package of Java classes) and native libraries (' .dll ', ' .lib ' for windows, ' .a ', ' .so ' for Linux and macOS).
To include these external packages into an Eclipse's project, right-click on the project Build Path Add External Archives Navigate to select the JAR files (' .jar ') to be included.
In 'Package Explorer', right-click on the JAR file added Properties:
To include native libraries (' .dll ', ' .lib ', ' .a ', ' .so '), select 'Native Library' 'Location Path' 'External Folder'.
To include the javadoc, select 'JavaDoc Location' 'JavaDoc URL' You can specify a local file or a remote link.
To include source file (for debugging), select 'Java Source Attachment'. All the above options are also accessible via project's property 'Build Path'.
Notes: The JAR files must be included in the CLASSPATH . The native library directories must be included in JRE's property ' java.library.path ', which normally but not necessarily includes all the paths from the PATH environment variable. Read 'External JAR files and Native Libraries'.
Creating a User Library: You can also create a Eclipse's user library to include a set of JAR files and native libraries, that can then be added into subsequent Eclipse projects.
For example, I created a user library for 'JOGL' as follows:
From 'Window' menu Preferences Java Build Path User Libraries New In 'User library name', enter ' jogl '. The 'User Library' dialog appears.
In 'User Library' dialog Select ' jogl ' Add JAR... Navigate to JOGL_HOME/lib , and select ' gluegen-rt.jar ' and ' jogl.jar '.
Expand the ' jogl.jar ' node Select 'Native library location: (none)' Edit... External Folder... select JOGL_HOME/lib .
Expand the ' jogl.jar ' node Select 'Javadoc location: (none) ' Edit... Javadoc in archive In 'Archive Path', 'Browse' and select the downloaded JOGL API documentation zip-file In 'Path within archive', 'Browse' and expand the zip-file to select the top-level path (if any) Validate. Alternatively, you can provide the path to the un-zipped javadocs. This is needed for Eclipse to display javadoc information about classes, fields, and methods.
You may provide the source files by editing 'Source attachment: (none)'. Source is needed only if you are interested to debug into the JOGL source codes. For EACH subsequent Java project created that uses JOGL, right-click on the project Build Path Add Libraries Select 'User Library' Check ' jogl '.
Running an External Program: Suppose that you want to run a Perl script on the selected file, you can configure an external tool as follows:
From 'Run' menu External Tools External Tools Configuration... The 'External Tools Configuration' dialog appears.
In 'Name', enter your tool name.
Choose the 'Main' tab In 'Location', 'Browse File System...' to choose the perl interpreter 'perl' In 'Arguments', enter ' path/scriptname.pl $resource_loc ', where $resource_loc is an Eclipse variable that denotes the currently selected resource with absolute path.
Choose the 'Common' tab In 'Standard Input and Output', uncheck 'Allocate Console', check 'File' and provide an output file (e.g., d:temp$resource_name.txt ).
(If you use the CYGWIN perl interpreter, need to set environment variable CYGWIN=nodosfilewarning to disable warning message.) To run the configured external tool, select a file run external tool tool name.
Viewing Hex Code of Primitive Variables in Debug mode: In debug perspective, 'Variable' panel Select the 'menu' (inverted triangle) Java Java Preferences... Primitive Display Options Check 'Display hexadecimal values (byte, short, char, int, long)'.
Adding a New Version of JDK/JRE: First, you can check the installed JDK/JRE via 'Window' menu 'Preferences' Expand 'Java' node 'Installed JREs'. Check the 'Location' current JRE installed to make sure that it is the intended one. You can use the 'Add' button to add a new version of JRE. For program development, I recommend that you add the JDK (instead of JRE). [The 'Location' decides the extension directory used for including additional JAR files, e.g., $JAVA_HOMEjrelibext .] For Web Developers
HTML Editor: Use the 'Web Page Editor' (available in Eclipse Java EE), which provides the design view (WYSISYG).
To use the 'Web Page Editor', right-click on the HTML file, open as 'Web Page Editor'.
To make the 'Web Page Editor' as default for HTML file, goto Window Preferenes General Editor File Associations .htm and .html Select 'Web page editor' default. File I/O in Eclipse
Suppose that your want to write a Java program, which inputs from a text file called ' xxxx.in ' and outputs to a text file called ' xxxx.out '. This is a little tricky under Eclipse due to:
When you create a text file in Windows' Notepad and saved it as ' xxxx.in ', Notepad will append the ' .txt ' to your file and it becomes ' xxxx.in.txt '. Worse still, the Windows' Explorer, by default, will not show the ' .txt ' extension. (The first thing I always do to an alien computer is to change this setting. From 'Tools' menu Folder Options... View Uncheck 'Hide extensions for known file types'.) You need to put a pair of double quotes around xxxx.in to override the default ' .txt ' extension. This is one good reason not to use Notepad for programming at all. You should use Eclipse to create the text file instead.
Which directory to keep the input file ' xxxx.in ' in Eclipse?
If you did not separate the sources and class files into two separate directories, then the answer is straight forward, because there is only one directory to place your input file.
If you choose to keep your sources and class files in two separate directories, eclipse will create two sub-directories 'src' and 'bin' under the base directory. BUT you need to put your input file ' xxxx.in ' in the base directory of your project, instead of the 'src' or 'bin'.. For writing simple programs:
Put the sources, class files, and the input/output files in the same directory. (When you create a new project, select 'Use project folder as root for sources and class files' in 'Project Layout'.) (But put your sources and class files in separate directories for big project.)
You can create you input file from eclipse directly via 'File' menu 'New' 'File'.
Remember to add a newline to the end of your input file.
You may need to right-click the project and select 'Refresh' to see the output file ' xxxx.out ' created in the package explorer.
To open the ' xxxx.in ' and ' xxxx.out ': right-click Open With Text Editor.
This is a sample JDK 1.5 program for file input/output:
Create the input text file called ' FileIOTest.in ' with the following contents and terminated with a newline: Writing Swing Applications using Eclipse GUI Builder
Eclipse provides a visual GUI builder called 'WindowBuilder' (@ https://www.eclipse.org/windowbuilder), which supports AWT/Swing, SWT (Eclipse's Standard Widget Toolkit - an alternative to JDK's AWT/Swing), XWT, GWT, eRCT. Step 0: Install WindowBuilder
To install 'WindowBuilder', goto 'Help' Install New Software In 'Work with', enter 'https://download.eclipse.org/windowbuilder/latest/' (You can find the proper link from 'http://www.eclipse.org/windowbuilder/download.php') Check 'WindowBuilder' Next Next Accept the licence Finish. Step 1: Create a New 'Java Application' Project
Choose 'File' menu 'New' 'Java project'.
The 'New Java Project' dialog pops up.
In the 'Project name' field, enter ' FirstSwingProject '.
Check 'Use default location'.
In the 'JRE' box, select 'Use default JRE (currently 'JDK1.x')'.
Click 'Finish'. Step 2: Create a Swing JFrame Subclass
Choose 'File' menu 'New' 'Others' 'WindowBuilder' 'Swing Designer' 'JFrame' 'Next'.
In the 'Create JFrame' dialog Enter 'SwingMain' in the 'Name' field 'Finish'.
Select the 'Design' pane.
In 'Layouts', select 'FlowLayout' and click on the 'design form'.
From 'Components', select ' JLabel ' and click on the design form. Change the label text to 'Counter: '. Select a 'JTextField' and place it on the design form. Change the text to '0'. Select a 'JButton' and place it on the design form. Change the text label to 'Count'.
To attach a event-handler to the button, double-click the JButton to switch into the 'Source' pane, with the event-handler skeleton created. Complete the actionPerformed() as follows: Add an instance variable called count as follow:
You can now ready run the program. Right-click on the project Run As Java Application. Eclipse Generated Codes
Study the codes generated by Eclipse GUI Builder, as follows, which is just a typical Swing application. Eclipse for C/C++ Programming
Here. Eclipse PDT (PHP Development Tool)
Here. Eclipse and Database Development (MySQL)
Reference: 'Data Tools Platform User Documentation' @ Eclipse Welcome page.
You need to install Eclipse for Java EE, MySQL and MySQL Connector/J Driver. Read 'How to install and get started with MySQL'.
To use Eclipse for MySQL development:
Switch to 'Database Development' perspective: From 'Window' menu Open Perspective Other Database Development.
Connect to MySQL database server: Start your MySQL database server. Right-click 'Database Connection' New.
In 'Connection Profile', choose 'MySQL' Next.
In 'Driver', choose 'New Driver Definition' Choose the MySQL Connector/J Driver In JAR List, select the MySQL Connector/J Driver JAR file (that you have installed). In 'Properties', 'General', specify URL (take note of the database name), User name and password Test Connection Finish.
In 'Datasource Explorer', you can 'connect' and 'disconnect' the connection.
To create a new SQL script, choose File New SQL File You may use an existing project or create a new project (General - Project or Web - Dynamic Web Project) Enter filename, and set the connection profile name Finish. Enter a SQL statement (e.g., SELECT * FROM tablename) Right-click on the text 'Execute Current Text' or 'Execute All'.
To use an existing SQL file, drop the file into a project and open the SQL file. In Connection profile, set the type and connection name. Right-click on a statement 'Execute ...'.
To CURD (create-update-read-delete) tables, in 'Datasource Explorer' (of the 'Database Development' perspective), expand 'database' to view the tables. Right-right on the table Datat Edit. Developing and Deploying Web Applications in Eclipse for Java EE Setting Up Eclipse for Web Development
Install 'Eclipse for Java EE (Enterprise Edition)'.
Install Tomcat (or Glassfish) server.
Configuring Web Server: Launch Eclipse Window Preferences Expand the 'Server' node 'Runtime Environments' 'Add...' Expand 'Apache' and select 'Apache Tomcat v7.0' Enter the 'Tomcat Installation Directory' 'Finish'. Writing a Hello-world JSP Page
Create a new Web Application: File New Dynamic Web Project (under 'Web' category) In 'Project Name', enter ' HelloJSP ' Finish.
Create a new JSP File: Right-click on the project ' HelloJSP ' New JSP File The parent folder shall be 'HelloJSP/WebContent' In 'File Name', enter ' Hello ' 'Finsih'.
Enter the following HTML/JSP codes within the body.../body tags:
To execute the JSP, right-click on ' Hello.jsp ' Run As Run on Server. Writing a Hello-world Servlet
Create a new Web Application: File New Dynamic Web Project (under 'Web' category) In 'Project Name', enter ' HelloServlet ' 'Finish'.
Create a new Servlet: Right-click on the project ' HelloServlet ' New Servlet In 'Java Package', enter ' hello '; in 'Class Name', enter ' HelloServlet ' Next In 'URL Mappings', select ' HelloServlet ', 'Edit' to ' Hello ' Next In 'Which method stubs would you like to create', check 'Inherited abstract method' and 'doGet' Finish.
In 'HelloServlet.java', enter the following codes:
(For Servlet 2.4/2.5 with Tomcat 6) The annotation @WebServlet is new in Servlet 3.0 and is not supported in Servlet 2.4/2.5. Hence, you need to manually configure the URL for the servlet in the Web Application Deployment Descriptor ' web.xml ' under directory ' WEB-INF ', as follows:
To execute the Servlet, right-click on the ' HelloServlet ' project 'Run As' 'Run on Server' Change the URL to ' http://localhost:8080/HelloServlet/sayhello '. Exporting a Web Application as a WAR file
Right-click on the project to be exported Export WAR File In 'Destination', specify the destination directory and filename (the filename shall be the web application name) Finish.
To deploy the war file in Tomcat, simply drop the war file into Tomcat's ' webapps ' folder. The war file will be automatically extracted and deployed. The web application name is the war-filename.
You could use WinZip (or WinRAR) to view the content of the war file, as war-file is in ZIP format. Writing a Hello-world JSF Page
[TODO] Debugging Web Applications
You can debug a webapp just like standalone application. For example, you can set breakpoints, single-step through the programs, etc.
REFERENCES RESOURCES
Eclipse mother site @ https://www.eclipse.org.
Eclipse documentation and user guides, accessible via Eclipse's Help and menu. Eclipse IDE for Java EE Developers
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Click here to file a bug against Eclipse Platform.
Click here to file a bug against Eclipse Git team provider. Eclipse for RCP and RAP Developers
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Java EE tools and BIRT reporting tool for Java developers to create Java EE and Web applications that also have reporting needs. Eclipse for Parallel Application Developers
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Tools for C, C++, Fortran, and UPC, including MPI, OpenMP, OpenACC, a parallel debugger, and remotely building, running and monitoring applications. Eclipse for Scout Developers
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Eclipse Scout is a framework to develop Java/Eclipse based business applications that run on the desktop, in browsers, and on mobile devices. This package includes a complete SDK, useful developer tools and source code. Download Eclipse Java Ee For Mac Eclipse for Testers
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This package contains Eclipse features that support the software development quality assurance process, such as Jubula and Mylyn.
