How to convert an ant snippet to Gradle - gradle

Question

Hi I am completely new to Gradle. Can anyone please help me as to how I can convert this ant task into Gradle. I am trying to see if I can learn by example.
<property file="build.properties"/>
<path id="classpath">
<fileset dir="${ear.dir}/EarContent/APP-INF">
<include name="**/*.jar" />
</fileset>
</path>
<target name="clean">
<delete file="${dist.dir}/*.jar" failonerror="false"/>
<delete failonerror="false">
<fileset dir="${build.dir}">
<include name="**/*.class" />
</fileset>
</delete>
</target>
<target name="init">
<mkdir dir="${dist.dir}"/>
<mkdir dir="${build.dir}/classes"/>
</target>
<target name="jar" depends="clean, init">
<javac srcdir="${src.dir}" destdir="${build.dir}/classes" debug="on">
<classpath refid="classpath"/>
</javac>
<jar destfile="${dist.dir}/phIntegration.jar">
<fileset dir="${build.dir}/classes" />
</jar>
</target>

Answer 1

I'm not convinced that trying move ANT build 1-1 to Gradle is a good learning exercise, although Gradle provides good integration with ANT.
Generally speaking, the build.gradle file for your project shall like somewhat like that:
apply plugin: 'java'
dependencies {
compile fileTree(dir: 'CLASSPATH_DIR', include: ['**/*.jar'])
//if you want you can use JARS from your filesystem as a classpath
//but you probably should use Ivy or Maven dependency management systems
}
sourceSets {
main {
java 'src/main/java'
//tweak the location of your source code, by default Gradle looks for sources in `src/main/java`
}
}
Once you invoke gradle clean build it will compile your sources and create a jar file containing the sources in build/libs directory. You can change the JARS name by adding the rootProject.name='your project name' in the settings.gradle directory.
The snippet uses Java plugin and the default behaviour of Gradle. If you want you can tweak its behaviour by using Delete Task or Jar Task.
If you define properly inputs/outputs of a task the init task won't be necessary since Gradle will take care of directories recreation if they're not existent. (Default tasks do that, if you start writing your own tasks you most probably will have to take care of that by your own)