我如何使用Ant来构建单个可执行文件.jar，该文件在.jar的/ lib目录中具有依赖项.jars？

Question

How can I use Ant to build a single executable .jar that has dependency .jars in it in a /lib dir in the . jar ?

I have a /lib directory in the project root file that contains all the binary dependency .jar s.

Answer 1

In java an executable jar has a specially formatted manifest , that includes the following attributes:

1. Main-Class
2. Class-Path

In ANT this is easily accomplished as follows with the jar task:

<jar destfile="${jar.dir}/${ant.project.name}.jar" basedir="${classes.dir}" includes="*.class">
    <manifest>
        <attribute name="Main-Class" value="${main-class}" />
        <attribute name="Class-Path" value="${jar-classpath}" />
    </manifest>
</jar>

For extra credit one can use the very useful manifestclasspath task to help assemble the correct classpath string.

<manifestclasspath property="jar-classpath" jarfile="${jar.dir}/${ant.project.name}.jar">
    <classpath>
        <fileset dir="/path/to/lib/dir" includes="*.jar"/>
    </classpath>
</manifestclasspath>