一个常用的ANT打包脚本

suppose folder structure is like:
   MyProject
                 ---src
                 ---lib
                 ---target
                 ---build.xml

And we want to generate the Jar which will contain the MANIFEST.MF having classpath and main class.
Here we will use ant to build the jar. All you need to do is to change the project name in 1st line and Main-Class value in 55th line  for build.xml, then type ant in command line. (You need to download the ant and include installation folder of ant in PATH system environment variable)

build.xml:
<project name="MyJar" default="package" basedir=".">

<!-- set global properties for this build -->
<property name="src" value="src"/>
<property name="lib" value="lib"/>
<property name="target" value="target"/>
<property name="build" value="target/classes"/>    
<property name="dist" value="target/dist"/>
   
<target name="init">
<!-- Create the time stamp -->
<tstamp/>
<!-- Create the build directory structure used by compile -->
<mkdir dir="${build}"/>
</target>
 
    
<path id="compile.class.path">
    <!--pathelement location="lib"/-->
    <fileset dir="${lib}">
    <include name="**/*.jar"/>
    </fileset>
</path>

<target name="compile" depends="init">
<!-- Compile the java code from ${src} into ${build} -->
    <javac srcdir="${src}" destdir="${build}" >
        <classpath refid="compile.class.path"/>
    </javac>
</target>
    
    
<target name="package" depends="compile">
    <pathconvert  property ="libs.project"  pathsep =" " >  
               <mapper>
                <chainedmapper>
               <!--  remove absolute path  -->
                  <flattenmapper/>
                   <!--  add lib/ prefix  -->
                   <globmapper  from ="*"  to ="${lib}/*"   />
                </chainedmapper >
              </mapper >
              <path >
                <!--  lib/buildhome contains all jar files, in several subdirectories  -->
                <fileset  dir ="${lib}" >
                  <include  name ="**/*.jar"   />
                </fileset >
              </path >
   </pathconvert >
<!-- Create the jar -->

<!-- Put everything in ${build} into the jar file -->
 <jar jarfile="HadoopExec.jar" basedir="${build}">
       <manifest >
           <attribute  name ="Main-Class"  value ="xxx.XxxxYyyy"  />
          <!--  finally, use the magically generated libs path  -->
         <attribute  name ="Class-Path"  value ="${libs.project}"   />
       </manifest>
 </jar>
</target>

<target name="clean">
<!-- Delete the ${build} and ${dist} directory trees -->
<delete dir="${build}"/>
<delete dir="${dist}"/>
</target>

</project>

 
执行jar:

java -jar MyJar

这样省去了设置classpath和指定main class的麻烦