Dinesh on Java

Ant build files are just text files, so simple way to create an Ant build file go to file->new file->Enter a name for the file->Create it. Ant’s build file, called build.xml should reside in the base directory of the project. However there is no restriction on the file name or its location. You are free to use other file names or save the build file in some other location.

By default the Ant editor only has an association with <b>build.xml</b> named files. So right now we are creating a file called build.xml in your application with the following contents in it.

<?xml version="1.0"?>
   <project name="Hello World" default="info" basedir=".">
   
   <target name="info">
      <echo>Hello World - Welcome to Apache Ant Tutorial!!!</echo>
   </target>
   
</project>

All build files require the project element and at least one target element. As per as our build file there is XML element project has three attributes as below.

• name-> The name of project and it is optional.
• default-> The name of default target and it mandatory. The default target for the build script. A project may contain any number of targets. This attribute specifies which target should be considered as the default.
• basedir-> The base or root directory and it is optional.

Now move to another XML element of Ant Build file build.xml is target. A target is a collection of tasks that you want to run as one unit. Targets can have dependencies on other targets. Let see below

<target name="clean" description="cleans up the build by deleting the build,dist, web directories">
     ......
</target>
<target name="init" depends="clean" description="Setup for build script">   
    ......
</target>
<target name="compile" depends="init" description="Compiles .java files to WAR directory">
      ......
</target>    
<target name ="makejar" description="Create a jar for the AlgoTest project" depends="compile">
    ......
</target>

As per as we have define targets in the above file have dependencies such as a makejar target may have a dependency on the compile target and compile target may have dependency on the init target and init target may have dependency on the clean target.

The target element has the following attributes:

• name-> The name of the target ant it is mandatory.
• depends-> Comma separated list of all targets that this target depends on and it is optional.
• description->A short description of the target and it is optional.
• if->Allows the execution of a target based on the trueness of a conditional attribute and it is optional.
• unless->Adds the target to the dependency list of the specified Extension Point. An Extension Point is similar to a target, but it does not have any tasks and it is optional.

To run the ant build file, open up command prompt and navigate to the folder where the build.xml resides, and type ant info.