Ant - Executing Java code

You can use Ant to execute the Java code. In the following example, the java class takes in an argument (administrator's email address) and send out an email.

NotifyAdministrator.java

public class NotifyAdministrator {
   public static void main(String[] args) {
      String email = args[0];
      notifyAdministratorviaEmail(email);
      System.out.println("Administrator "+email+" has been notified");
   }
   public static void notifyAdministratorviaEmail(String email){
      //......
   }
}

Here is a simple build that executes this java class.

<?xml version="1.0"?>
<project name="sample" default="run">
   <property name="src.dir" value="."/>
   <property name="build.dir" value="build"/>
   <property name="main.class" value="NotifyAdministrator"/>

   <target name="init">
      <mkdir dir="${build.dir}"/>
   </target>

   <target name="compile" depends="init">
      <javac srcdir="${src.dir}" destdir="${build.dir}" includeantruntime="false"/>
   </target>

   <target name="run" depends="compile">
      <java classname="${main.class}" classpath="${build.dir}" fork="true">
         <arg line="admin@test.com"/>
      </java>
   </target>

   <target name="clean">
      <delete dir="${build.dir}"/>
   </target>

</project>

When the build is executed, it produces the following outcome −

C:\>ant
Buildfile: C:\build.xml

init:

compile:
    [javac] Compiling 1 source file to D:\ant\build

run:
     [java] Administrator admin@test.com has been notified

BUILD SUCCESSFUL
Total time: 0 seconds

In this example, the java code does a simple thing which is, to send an email. We could have used the built in the Ant task to do that.

However, now that you have got the idea, you can extend your build file to call the java code that performs complicated things. For example: encrypts your source code.