Demo in Ant build.xml

< project > 

         < target  name ="clean" > 
                 < delete  dir ="build" /> 
         </ target > 

         < target  name ="compile" > 
                 < mkdir  dir ="build/classes" /> 
                 < javac  srcdir ="src"  destdir ="build/classes" /> 
         </ target > 

         < target  name ="jar" > 
                 < mkdir  dir ="build/jar" /> 
                 < jar  destfile ="build/jar/HelloWorld.jar"  basedir ="build/classes" > 
                         < manifest > 
                                 < attribute  name ="Main-Class"  value ="demo.HelloWorld" /> 
                         </ manifest > 
                 </ jar > 
         </ target > 

         < target  name ="run" > 
                 < java  jar ="build/jar/HelloWorld.jar"  fork ="true" /> 
         </ target > 

</ project >

< project  name ="antdemo"  basedir ="."  default ="deploy" > 

  <!--  Project settings --> 
   < property  name ="project.distname"  value ="antdemo"  /> 
   < property  name ="src.dir"  value ="src"  /> 
   < property  name ="lib.dir"  value ="lib"  /> 

  <!--  Local system paths --> 
   < property  name ="build.dir"  value ="build"  /> 
   < property  name ="classes.dir"  value ="${build.dir}/classes"  /> 
   < property  name ="jar.dir"  value ="${build.dir}/jars"  /> 

   < property  name ="main-class"  value ="demo.HelloWorld"  /> 

  <!--  outer jar lib --> 
   < path  id ="classpath" > 
     < fileset  dir ="${lib.dir}"  includes ="**/*.jar"  /> 
   </ path > 

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

   < target  name ="compile" > 
     < mkdir  dir ="${classes.dir}"  /> 
    <!--  In javac, we should improt the chasspathref which needed. --> 
     < javac  srcdir ="${src.dir}"  destdir ="${classes.dir}"   classpathref ="classpath"  />     
      < copy  todir ="${classes.dir}" > 
                         < fileset  dir ="${src.dir}"  excludes ="**/*.java" /> 
                 </ copy > 
     
   </ target > 

  <!--  Create jar --> 
   < target  name ="jar"  depends ="compile" > 
     < mkdir  dir ="${jar.dir}"  /> 
     < jar  destfile ="${jar.dir}/${ant.project.name}.jar"  basedir ="${classes.dir}" > 
       < manifest > 
         < attribute  name ="Main-Class"  value ="${main-class}"  /> 
       </ manifest > 
     </ jar > 
   </ target > 

   < target  name ="run"  depends ="jar" > 
    <!--  <java jar="${jar.dir}/${ant.project.name}.jar" fork="true"/>--> 
    <!--  set classpath --> 
     < java  fork ="true"  classname ="${main-class}" > 
       < classpath > 
         < path  refid ="classpath"  /> 
         < path  location ="${jar.dir}/${ant.project.name}.jar"  /> 
       </ classpath > 
     </ java > 
   </ target > 

   < target  name ="clean-build"  depends ="clean,jar"  /> 

   < target  name ="deploy"  depends ="clean,run"  /> 


</ project >