Java/Packaging/Eclipse projects

From openSUSE

The Eclipse is one of the most popular IDE's over the world. Unfortunatelly don't use a standardize build system, but has it owns. For non-interactive build process (eg. build of rpm), there're some things, which are necessary to do.

Requirements

For Java development, you need the Eclipse Java development tools (eclipse-jdt). For produce of standard build.xml you need the an Eclipse Plugin Development Environment (eclipse-pde) installed.

zypper install eclipse-pde

Eclipse project

Run eclipse and open/create a Java project. By default, eclipse creates similar files structure:

$ ls /home/mvyskocil/workspace/sample
.classpath
.project
bin
src

Move to the Package Explorer - a list of the packages in your project and shows the context menu ...

select PDE Tools/Converts projects to Plug-In Projects ...

... select the projects to convert ...

Now, we have a build.properties file. So for the generate of the build.xml ...

... select a PDE Tools/Create Ant Build File ...

... and voila, you've got an build.xml.

Create a jar

The default target doesn't creates a jar file. The jar was created in build.update.jar target, so type:

$ ant build.update.jar
Buildfile: build.xml

properties:

init:

build.update.jar:
    [mkdir] Created dir: /home/mvyskocil/workspace/sample/temp.folder

properties:

init:

build.jars:

properties:

init:

@dot:
    [mkdir] Created dir: /home/mvyskocil/workspace/sample/temp.folder/@dot.bin
    [javac] Compiling 1 source file to /home/mvyskocil/workspace/sample/temp.folder/@dot.bin
     [copy] Copying 1 file to /home/mvyskocil/workspace/sample/@dot
   [delete] Deleting directory /home/mvyskocil/workspace/sample/temp.folder/@dot.bin

properties:

init:

gather.bin.parts:
    [mkdir] Created dir: /home/mvyskocil/workspace/sample/temp.folder/sample_1.0.0
     [copy] Copying 1 file to /home/mvyskocil/workspace/sample/temp.folder/sample_1.0.0
     [copy] Copying 1 file to /home/mvyskocil/workspace/sample/temp.folder/sample_1.0.0
      [jar] Building jar: /home/mvyskocil/workspace/sample/sample_1.0.0.jar
      [jar] Building jar: /home/mvyskocil/workspace/sample/sample_1.0.0.jar
   [delete] Deleting directory /home/mvyskocil/workspace/sample/temp.folder

BUILD SUCCESSFUL
Total time: 17 seconds
$ ls sample_1.0.0.jar
sample_1.0.0.jar

Tweaking the generated build.xml

You almost certainly want to set javacFailOnError to true, otherwise ant will report BUILD SUCCESSFUL even if nothing is build due to a missing class. Also, to make the build.xml more portable, it's a good idea to match the Eclipse jars in the classpath by wildcards instead of hardcoding the exact version number, e.g.

<path id="@dot.classpath">
	<fileset dir="/usr/share/eclipse/plugins">
		<include name="org.eclipse.ui_*.jar"/>
		<include name="org.eclipse.core.runtime_*.jar"/>
		<include name="org.eclipse.osgi_*.jar"/>
		<include name="org.eclipse.equinox.common_*.jar"/>

Have a look at the build.xml used in the Build Service plugin for eclipse for an example of such build file.