how to update buildversion.txt file after build using ant and jenkins - ant

Question

I execute an ant xml file using jenkins. I have to update the versionbuild.txt file information before making war.
my ant tasks are init, clean, prepare, compile, war
before making war, I want to access some parameters like date_of_build, build_number, jdk_compiler, compiler_platform, build_person. Update these in text file named versionbuild.txt file and archive into war.

Answer 1

I am doing something similar in one of my build scripts. Basically creating a properties file which I place as a resource in the source folder. Here's the snippet:
<target name="init">
<!-- Format the build number to a 4 figures integer with leading zeroes if required -->
<!-- The build number is also incremented by 1 -->
<propertyfile file="${build.number.file}">
<entry key="build.number" type="int" default="0000" operation="+" pattern="0000" />
</propertyfile>
<!-- Read the build number -->
<property file="${build.number.file}"/>
<!-- create the build date and time with time zone -->
<tstamp>
<format property="readable.now" pattern="yyyy-MM-dd hh:mm z"/>
</tstamp>
<!-- Write thebuild and version information to a resource file -->
<!-- The resource file will be part of the corresponding jar -->
<propertyfile file="${node}/src/resources/META-INF/jppf-version.properties">
<entry key="version.number" type="string" value="${version.number}"/>
<entry key="build.number" type="string" value="${build.number}"/>
<entry key="build.date" type="string" value="${readable.now}"/>
</propertyfile>
</target>
The resulting file looks like this:
#Wed, 30 Apr 2014 07:45:12 +0200
version.number=4.2 alpha
build.number=1352
build.date=2014-04-30 07\:45 CEST
Obviously, some of the data you need is not in there, but you can easily add them as <entry> elements, using the name of the corresponding system properties as the value, for instance:
<propertyfile file="${path.to}/versionbuild.txt">
<entry key="build_number" type="string" value="${build.number}"/>
<entry key="date_of_build" type="string" value="${readable.now}"/>
<entry key="jdk_compiler" type="string" value="${java.vm.version}"/>
<entry key="jdk_compiler" type="string" value="${os.name}"/>
<entry key="build_person" type="string" value="${user.name}"/>
</propertyfile>