Ant 错误“线程异常”AWT-EventQueue-0“java.lang.NoClassDefFoundError：com/sun/jna/Library”

Question

我有一个使用多个外部库的 Java 程序。 该程序在 Eclipse IDE 中编译和运行没有任何问题。 但是，当使用 ant build.xml 时，编译工作正常，但在运行时会引发以下异常。

run:
 [java] Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: com/sun/jna/Library
 [java]     at java.lang.ClassLoader.defineClass1(Native Method)
 [java]     at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
 [java]     at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
 [java]     at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
 [java]     at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
 [java]     at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
 [java]     at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
 [java]     at java.security.AccessController.doPrivileged(Native Method)
 [java]     at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
 [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
 [java]     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
 [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
 [java]     at org.freedesktop.gstreamer.Gst.getVersion(Unknown Source)
 [java]     at org.freedesktop.gstreamer.Gst.init(Unknown Source)
 [java]     at org.freedesktop.gstreamer.Gst.init(Unknown Source)
 [java]     at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
 [java]     at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
 [java]     at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
 [java]     at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
 [java]     at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
 [java]     at java.awt.Component.processMouseEvent(Component.java:6539)
 [java]     at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
 [java]     at java.awt.Component.processEvent(Component.java:6304)
 [java]     at java.awt.Container.processEvent(Container.java:2239)
 [java]     at java.awt.Component.dispatchEventImpl(Component.java:4889)
 [java]     at java.awt.Container.dispatchEventImpl(Container.java:2297)
 [java]     at java.awt.Component.dispatchEvent(Component.java:4711)
 [java]     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4904)
 [java]     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4535)
 [java]     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4476)
 [java]     at java.awt.Container.dispatchEventImpl(Container.java:2283)
 [java]     at java.awt.Window.dispatchEventImpl(Window.java:2746)
 [java]     at java.awt.Component.dispatchEvent(Component.java:4711)
 [java]     at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760)
 [java]     at java.awt.EventQueue.access$500(EventQueue.java:97)
 [java]     at java.awt.EventQueue$3.run(EventQueue.java:709)
 [java]     at java.awt.EventQueue$3.run(EventQueue.java:703)
 [java]     at java.security.AccessController.doPrivileged(Native Method)
 [java]     at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
 [java]     at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:84)
 [java]     at java.awt.EventQueue$4.run(EventQueue.java:733)
 [java]     at java.awt.EventQueue$4.run(EventQueue.java:731)
 [java]     at java.security.AccessController.doPrivileged(Native Method)
 [java]     at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
 [java]     at java.awt.EventQueue.dispatchEvent(EventQueue.java:730)
 [java]     at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
 [java]     at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
 [java]     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
 [java]     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
 [java]     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
 [java]     at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
 [java] Caused by: java.lang.ClassNotFoundException: com.sun.jna.Library
 [java]     at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
 [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
 [java]     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
 [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
 [java]     ... 52 more

我正在使用的构建脚本如下所示。

<property name="src.dir"     value="src/org"/>
<property name="build.dir"   value="build"/>
<property name="classes.dir" value="${build.dir}/classes"/>
<property name="jar.dir"     value="${build.dir}/jar"/>
<property name="lib.dir"     value="Libs" />

<property name="main-class"  value="org.ai.receiver.DashboardLauncher"/>

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

<target name="compile">
    <mkdir dir="${classes.dir}"/>
    <javac srcdir="${src.dir}/ai/receiver:${src.dir}/freedesktop/gstreamer" destdir="${classes.dir}" includeantruntime="false">
    <classpath>
        <fileset dir="${lib.dir}">
            <include name="**/*.jar" />
        </fileset>
    </classpath>
    </javac>
</target>
<target name="jar" depends="compile">
    <mkdir dir="${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">
        <classpath>
            <pathelement location="Libs/jna.jar:Libs/jna-platform.jar:Libs/swt.jar"/>
            <fileset dir="${lib.dir}">
                <include name="**/*.jar" />
            </fileset>
         </classpath>
    </java>
</target>
<target name="clean-build" depends="clean,jar"/>
<target name="main" depends="clean,run"/>

所需的外部库“jna.jar”、“jna-platform.jar”和“swt.jar”文件位于“Lib”目录中。

在我看来，这些外部库在运行时没有正确加载，但在编译时它们被正确链接。 在此github 问题跟踪器中讨论了类似的问题，但该讨论并未提供适当的解决方案。

你能帮我解决这个问题吗？

谢谢你。

Answer 1

此问题已通过将目标更改为.jar 得到解决，如下所示：

<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>
        <zipgroupfileset dir="Libs" includes="*.jar" />
    </jar>
</target>