Ant build scripts - ant

I am using ant script for generating war file, it will generate the war file. please see the below script
<target name="war" depends="build">
<mkdir dir="${dist}" />
<jar destfile="${dist}/${proj_name}.war" basedir="${build}" />
</target>
If it generates a new war file, then i want to have a property to set the value as "newupdates" otherwise i want to know "noupdates"

A strategy to do this could be to use the UpToDate task to set the property.
You just have to copy the war file to war.bak just after performing the uptodate check, to prepare for the next run.
Another strategy (probably even better) would be to use the UpToDate task to determine if the war has to be generated, setting a property, e.g myuptodateproperty. Then call your war generation target, and make sure it has an if=${myuptodateproperty} constraint, in order not to regenerate the war if it is not needed.
You can use something in the line of (untested code, may need some work):
<target name="war" depends="clean,fillbuildanddist,build">
<mkdir dir="${dist}" />
<uptodate targetfile="${dist}/${proj_name}.war" property="uptodatewar">
<fileset dir="${build}" />
</uptodate>
<antcall target="makewar" />
</target>
<target name="makewar" unless="uptodatewar">
<jar destfile="${dist}/${proj_name}.war" basedir="${build}" />
</target>
With this, the property uptodatewar should be set to true only if the war does not need to be rebuilt, and thus the jar task will only be called in this case. In targets that depend on the war target, you can use the uptodatewar to perform tasks only if the war is new.

Related

is there a way to make a jar with the Eclipse generated ant script?

To my surprise the build.xml file generated by Eclipse (Neon) for Java has no element containing an invocation of a jar task. As often is the case with code generation I think you have to use it and make no edits so that you can regenerate - or - avoid code generation completely. A comment in the generated file suggests it might be possible to avoid edits by extending the capabilities by importing.
<!-- WARNING: Eclipse auto-generated file.
Any modifications will be overwritten.
To include a user specific buildfile here, simply create one in the same
directory with the processing instruction <?eclipse.ant.import?>
as the first entry and export the buildfile again. -->
I thought I would be able to use the <?eclipse.ant.import?> element in an second file called export.xml. In ant scripting there is supposed to be one project per buildfile so now there is a second project with a dependency on a target in the first project.
Regenerating build.xml reveals that it contains an "import" as expected.
<import file="export.xml"/>
Unfortunately this does not work. Running ant, which I do from the command line, just seems to result in the export/jar project being ignored.
The generated script with the import element (nested on the 7th line)...
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<project basedir="." default="build" name="ohana1">
<property environment="env"/>
<property name="debuglevel" value="source,lines,vars"/>
<property name="target" value="1.8"/>
<property name="source" value="1.8"/>
<import file="export.xml"/>
<path id="ohana1.classpath">
<pathelement location="bin"/>
<pathelement location="../export/ohana1/commons-collections-3.2.1.jar"/>
</path>
<target name="init">
<mkdir dir="bin"/>
<copy includeemptydirs="false" todir="bin">
<fileset dir="src">
<exclude name="**/*.launch"/>
<exclude name="**/*.java"/>
</fileset>
</copy>
</target>
<target name="clean">
<delete dir="bin"/>
</target>
<target depends="clean" name="cleanall"/>
<target depends="build-subprojects,build-project" name="build"/>
<target name="build-subprojects"/>
<target depends="init" name="build-project">
<echo message="${ant.project.name}: ${ant.file}"/>
<javac debug="true" debuglevel="${debuglevel}" destdir="bin" includeantruntime="false" source="${source}" target="${target}">
<src path="src"/>
<classpath refid="ohana1.classpath"/>
</javac>
</target>
<target description="Build all projects which reference this project. Useful to propagate changes." name="build-refprojects"/>
<target description="copy Eclipse compiler jars to ant lib directory" name="init-eclipse-compiler">
<copy todir="${ant.library.dir}">
<fileset dir="${ECLIPSE_HOME}/plugins" includes="org.eclipse.jdt.core_*.jar"/>
</copy>
<unzip dest="${ant.library.dir}">
<patternset includes="jdtCompilerAdapter.jar"/>
<fileset dir="${ECLIPSE_HOME}/plugins" includes="org.eclipse.jdt.core_*.jar"/>
</unzip>
</target>
<target description="compile project with Eclipse compiler" name="build-eclipse-compiler">
<property name="build.compiler" value="org.eclipse.jdt.core.JDTCompilerAdapter"/>
<antcall target="build"/>
</target>
</project>
The export.xml file meant to make a jar...
<?eclipse.ant.import?>
<project basedir="." default="export" name="ohana1Export">
<target depends="build,make-jar" name="export"/>
<target name="make-jar">
<jar destfile="../export/ohana1/${ant.project.name}.jar" basedir="bin"/>
</target>
</project>
Note that the Eclipse Ant editor complains about this export.xml file because the target named build, which is a dependency, does not exist in this project/buildfile. The build target is in the generated build.xml. That error might be coming from a "dumb" editor so I went ahead to do a run of ant. Invoking ant from the command line I find that there is no jar file made.
Should I conclude that Eclipse's ant script generator is useless if you need to export a .jar file and that a human should maintain the ant script that meets all the requirements?
Yes, in my opinion the exported build.xml is useless, as of Eclipse Neon, if the intention is to make a .jar.
Specifically do the following.
Manually write the trivial ant script that exports a .jar. The link at the bottom of this post has verbatim text on what the script might look like. You can use the built-in Xml Editor via New > Other > XML > XML File to create this new file which might be called makeJar.xml and save it. If the icon shown in the Package Explorer is still a plain XML file icon refreshing the project may change the icon to an Ant file icon. In the future, you can use Open With to get the Ant Editor instead of the XML Editor. This script will replace the manual exporting of a .jar that the user would otherwise perform via Eclipse.
This script can be added to Project > Properties > Builders. It would be placed second in the list of Builders. First in the list of Builders is the Java Builder which should already exist. When an Eclipse build is invoked the entire list of Builders will be processed in the order shown in the list of Builders. Thus not only will .class files be generated but also the .jar.
What is achieved is greater automation since the .class generation and .jar generation are now integrated, which arguably was the point of using the exported build.xml in a failed attempt to generate the .jar.
Here is the dialog at Project > Properties > Builders that you can use to create a new Builder. Select New then select Ant Builder. I gave the name makeJar to the new Builder.
Here is the dialog for the new Ant Builder that will allow you to browse to your buildfile which is your manually written Ant script that creates a .jar file. In this example the script is makeJar.xml. It also allows you to browse to the base directory to be used when the script is run.
After setting up the new Builder, a project "clean" or project "build" will create .class files and also the .jar.
Eclipse's documentation on this subject is at the link. Note that it seems impossible to link the exact page that contains the instructions so you have to browse down the documentation tree to the section about "Ant buildfiles as project builders".
Link to Eclipse and Ant

How to verify wheter ${property}.attribute is set in ant

I have multiple projects. Each of the project may or may not have a dependent classes. If I have dependent classes I have to build a jar based on the java files in the class property and add to project1 jar if the property is specified or it should be ignored.
Now I have to dynamically loop through all of the projects and in the target i have to test for the existance of the property and build if the property exist.
<target name="test">
<foreach list="${projects}" target="test2" param="project"/>
</target>
<target name="test2">
<!-- Here i have to test wheter ${project}.class exist or not-->
</target>
The following is a sample property file
projects=project1,project2,...
project1.class=class1.java,class2.java
Here project2 doesn't have a .class property,So it should not build a dependency jar. How can I test the existance of the property . I know is set can be used to know the status of property but this comes dynamically can someone help on this ?
You are on the right track with <isset>:
<target name="test2">
<if>
<isset property="${project}.class"/>
<then>
<echo message="${project}.class exists -- let's run a build"/>
</then>
</if>
</target>

Ant: javac with proc:only from Ant?

Is there any way to enforce javac task to invoke only annotation processing, without compilation. -proc:only javac option is supposed to enforce such behaviour, according to javac documentation.
But the following snippet of ant buildfile:
<target name="apt">
<javac srcdir="src" destdir="bin" includeantruntime="false">
<compilerarg value="-proc:only"/>
</javac>
</target>
Compiles project anyway. I experimented with other <compilerarg> tag versions (e.g. line instead of value) but nothing helped.
Avoid specifying the "destdir" attribute of the task, or use an empty directory as a destination for class files. The Ant "javac" task will then look for the class files either in the base directory (if you leave "destdir" unset) or in the empty directory. Because it will not find the classs files there, it will not exclude the potentially up-to-date sources from the compilation and execute "javac" on the sources from the directory specified in the "srcdir" attribute.
Your code would therefore look like this:
<target name="apt">
<javac srcdir="src" includeantruntime="false">
<compilerarg value="-proc:only" />
</javac>
</target>
or, if you use the empty directory approach, like this:
<target name="apt">
<mkdir dir="empty" />
<javac srcdir="src" destdir="empty" includeantruntime="false">
<compilerarg value="-proc:only" />
</javac>
</target>
The second approach is slightly more complex but a bit more clean. Usually your project will have an output directory where you put compiled classes and packaged jars, so adding an extra empty directory there would not hurt. As of Ant version 1.9.4, I did not find any other way to do annotation processing from Ant independently of compilation, even though a simple "force" attribute in the "javac" task could solve this problem.

Creating an ear-File with ant

I am new to ant i referred many sites , i need to build.xml for my project which consists
of two modules i have application.xml file which represents corresponding war file
so my question is it sufficient to add the application.xml file
<ear destfile="${dist.dir}/${ant.project.name}.ear" appxml="${conf.dir}/application.xml">
<metainf dir="${build.dir}/META-INF"/>
<fileset dir="${dist.dir}" includes="*.jar,*.war"/>
</ear>
whether this will refer the corresponding war files or i need to compile the whole scenario please let me know. how solve this.
I'm not 100% sure what you're asking.
In order to use the <ear> task, you already need to have compiled the required jars and wars.
If those jars and wars have already been built, you simply refer to them in your <ear> task as you did in your example. The application.xml must already exist before you build your ear. The application.xml doesn't build the jars and wars, you have to do that.
If you haven't already built the wars and jars, you need to do that first. A general outline of a build.xml looks something like this:
<project name="foo" basedir="." default="package">
<!-- Some standard properties you've defined -->
<property name="target.dir" value="${basedir}/target"/>
<property name="xxx" value="yyy"/>
<property name="xxx" value="yyy"/>
<property name="xxx" value="yyy"/>
<!-- Compile properties that allow overrides -->
<property name="javac.nowarn" value="false"/>
<property name="javac.listfiles" value="false"/>
<property name="javac.srcdir" value="source"/>
<property name="javac.distdir" value="${target.dir}/classes"/>
<target name="clean"
description="cleans everything nice and shiny">
<delete dir="${target.dir}"/>
</target>
<target name="compile"
description="Compiles everything">
<mkdir dir="${javac.distdir}"/>
<javac srcdir="${javac.srcdir}"
destdir="${javac.destdir}"
[...]
[...]/>
</target>
<target name="package.jar"
depends="compile"
description="Package jarfile">
<jar destfile="${target.dir}/jarname.jar"
[...]
[...]/>
</target>
<target name="package.jar2"
depends="compile"
description="Package jarfile">
<jar destfile="${target.dir}/jarname2.jar"
[...]
[...]/>
</target>
<target name="package.war"
depends="compile"
description="Package jarfile">
<war destfile="${target.dir}/jarname.jar"
[...]
[...]/>
</target>
<target name="package"
depends="package.jar"
description="Make the ear">
<ear destfile="${target.dir}/earfile.ear"
[...]/>
</target>
</project>
Basically, it consists of a bunch of targets and each target does one task. You can have targets depend upon other targets. For example, this particular build.xml will automatically run the package task. The package task depends upon the package.jar task which depends upon the compile task. Thus, the build.xml file will first call compile, then package.jar, then package.
The important thing to remember is that you don't specify the order of the events. You let Ant figure that out, and you let Ant figure out what you need to do. Let's say you've modified a java source file. Ant knows that it has to recompile only that one file. It also knows that it might have to rebuild the jarfile that contains that classfile. And, it then knows it has to rebuild the ear. Most tasks can figure it out on their own, and you don't do a clean for each build. (You notice that the clean target isn't called by package or compile. You have to call it manually).
The only other thing I recommend is that you try to keep your work area clean. Any files you create should be put into the ${target.dir} directory. That way, when you do a clean, you only have to delete that one directory.
I hope this answer your question.

How do I pass an argument to an Ant task?

I'm not very good with Ant, but we're using it as a build tool. Right now, we can run "ant test" and it'll run through all the unit tests.
However, I'd love to be able to do something like ant test some_module and have it accept some_module as a parameter, and only test that.
I haven't been able to find how to pass command line args to Ant - any ideas?
One solution might be as follows. (I have a project that does this.)
Have a separate target similar to test with a fileset that restricts the test to one class only. Then pass the name of that class using -D at the ant command line:
ant -Dtest.module=MyClassUnderTest single_test
In the build.xml (highly reduced):
<target name="single_test" depends="compile" description="Run one unit test">
<junit>
<batchtest>
<fileset dir="${test.dir}" includes="**/${test.module}.class" />
</batchtest>
</junit>
</target>
You can also define a property with an optional default value that can be replaced via command line, e.g.
<target name="test">
<property name="moduleName" value="default-module" />
<echo message="Testing Module: ${moduleName}"/>
....
</target>
and run it as:
ant test -DmoduleName=ModuleX
What about using some conditional in your test target and the specifying -Dcondition=true?
<target name="test" depends="_test, _test_if_true>
...
</target>
<target name="_test_if_true" if="condition">
...
</target>
<target name="_test" unless="condition">
...
</target>
Adapted a bit from the ant faq.
You can define a property on commandline when invoking ant:
ant -Dtest.module=mymodulename
Then you can use it as any other ant property:
...
<fileset dir="${test.dir}" includes="**/${test.module}.class" />
...
Have a look at Ant's manual.
I tried the solutions posted here for the very same original question. Yes just use ant -D<arg_name>. THe -D is a "keyword" I guess. I'm no ant expert and have not read the manuals in detail. Then inside the ant XML files can be accessed like: ${arg_name}
For instance you can have an argument name like: arg.myarg, so in XML ${arg.myarg}.
Ant really doesn't have parameters_ for the build file. I can think of a few ways to do this:
Use a special target to specify the tests. You can use the <for/> task from AntContrib to allow you to specify multiple tests. You'll need to download the Ant-Contrib jar file. I recommend placing it inside your project under the `${basedir}/antlib/antcontrib" directory. That way, when others checkout your project, they get the needed Ant-Contrib jar file.
<property name="antlib.dir" value="${basedir}/antlib"/>
<property name="antcontrib.dir" value="${antlib}/antcontrib"/>
<!-- Set up the ant contrib tasks for your use -->
<taskdef resource="net/sf/antcontrib/antlib.xml">
<classpath>
<fileset dir="${antcontrib.dir}"/>
</classpath>
</taskdef>
<target name="select-test"
description="Select the tests to run"
depends="test-compile"
if="junit-tests">
<for parameter="module"
list="${junit-tests}"
delimiter=" ">
<sequential>
<junit
fork="true"
...>
<batchtest todir="$target/unit-tests">
<fileset dir="${test.destdir}">
<include name="**/#{module}.class"/>
</fileset>
</junit>
</sequential>
</for>
</target>
You cab now run multiple tests like this:
$ ant -D"test-one test-two test-three" select-test
You could try this to access one target at a time. Add these lines to your build.xml file :
<project name="whatever" default="default">
<input message="Please select module:" addproperty="mod" />
<target name="default" depends="${mod}/>
...
</project>
This allows you to enter the module you want to execute and execute that itself instead of running the whole build.xml
You might need to make a few more changes to your build.xml for this to work perfectly.
For the arguments , there is Facility called property. You need to set the property. As in ANT plain arguments is taken as target name.
Lest say you have two modules in your project ModuleX and ModuleY where ModuleX has 2 testcases to run and ModuleY with 10 testcases.
You could do something like this :
ant runTestsOnModule -Dtestmodule="ModuleX"
OR to test all modules by calling
ant tests
<target name="runTestsOnModule">
<antCall target="testcase${testmodule}"/>
</target>'
<! -- run single module -->
<target name="runTestsOnModule">
<antCall target="testcase${testmodule}"/>
</target>
<!--run all tests-->
<target name="tests">
<antcall target="testcaseModuleX">
<antcall target="testCaseModuleY">
</target>
<target name="testcaseModuleX">
..run junit task to call 2 testcase
</target>
<target name="testcaseModuleY">
....run junit task to call 10 testcase
</target>

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