run a jar file (generated by ant) in command line

问题

I have a build.xml file that works fine. The problem is that the generated jar file, and I need to run it without 'ant run'

How can I run the jar file? running with

java -jar Main.jar main.Main

gives me:

Exception in thread "main" java.lang.NoClassDefFoundError: org/neo4j/graphdb/GraphDatabaseService

This is how I'm creating the jar file (build.xml):

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

<target name="compile">
    <mkdir dir="${build.dir}"/>
    <mkdir dir="${build.dir}/${conf.dir}"/>
    <javac srcdir="${src.dir}" destdir="${build.dir}" classpathref="classpath" includeantruntime="false"/>
    <copy todir="${build.dir}/${conf.dir}">
        <fileset dir="${conf.dir}"/>
    </copy>
</target>

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

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

The "ant run" task works fine with this jar. How can I run this project without ant?

回答1:

Use java -cp Main.jar main.Main, -jar is for bundled jars with a Manifest saying which class is to be used as the main class. What you're doing with -cp (and within your ant build file) is just putting it on the main path: you're specifying main.Main as the main class explicitly, not within a manifest.

You should also put the other jars on the classpath (e.g. -cp lib/example1.jar:lib/example2.jar:Main.jar). Depending on what matches **/*.jar, there may be a number of them.