java - Apache Ant java.lang.NoClassDefFoundError

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可能的答案 Stack Over flow question

我的问题与上述线程中描述的相同。我已经完成了解决方案，但它不起作用。ant compile 完美运行。 ant jar 说无法加载主类

Exception in thread "main" java.lang.NoClassDefFoundError: LoadServer (wrong name: org/module/loader/LoadServer)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:449)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:71)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

我在命令行做了以下操作

JAVA_HOME="/usr/local/java/jdk1.7.0_21"
ANT_HOME="/usr/share/ant/"
PATH="$ANT_HOME/bin:$PATH"

此外，如果我启动一个新终端并键入 echo$JAVA_HOME，它会显示上述结果，但 echo$ANT_HOME 会给出 null。

here is a screen shot

初始错误

     <project name="Raxa-4" basedir="." default="main">

    <property name="src.dir"      value="src"/>
    <property name="prop.dir"     value="properties"/>
    <property name="resource.dir" value="resource"/>
    <property name="lib.dir"      value="lib"/>
    <property name="build.dir"    value="build"/>
    <property name="classes.dir"  value="${build.dir}/classes"/>
    <property name="jar.dir"      value="${build.dir}/jar"/>
    <property name="main-class"   value="org.raxa.module.loader.LoadServer"/>

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

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

    <target name="compile">
        <mkdir dir="${classes.dir}"/>
        <javac srcdir="${src.dir}" destdir="${classes.dir}" classpathref="classpath" includeantruntime="false" />
        <copy todir="${classes.dir}">
            <fileset dir="${resource.dir}" excludes="**/*.java"/>
            <fileset dir="${prop.dir}" excludes="**/*.java"/>
        </copy>
    </target>

   <target name="jar" depends="compile">
        <mkdir dir="${jar.dir}"/>
         <classpath>
            <path refid="classpath"/>
            <path location="${jar.dir}/${ant.project.name}.jar"/>
        </classpath>
        </jar>
    </target>


    <target name="run" depends="jar">
        <java jar="${jar.dir}/${ant.project.name}.jar" fork="true"/>

    </target>

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

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

</project>

编辑:

    <property name="src.dir"      value="src"/>
    <property name="prop.dir"     value="properties"/>
    <property name="resource.dir" value="resource"/>
    <property name="lib.dir"      value="lib"/>
    <property name="build.dir"    value="build"/>
    <property name="classes.dir"  value="${build.dir}/classes"/>
    <property name="jar.dir"      value="${build.dir}/jar"/>
    <property name="main-class"   value="org.raxa.module.loader.LoadServer"/>

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

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

    <target name="compile">
        <mkdir dir="${classes.dir}"/>
        <javac srcdir="${src.dir}" destdir="${classes.dir}" classpathref="classpath" includeantruntime="false" />
        <copy todir="${classes.dir}">
            <fileset dir="${resource.dir}" excludes="**/*.java"/>
            <fileset dir="${prop.dir}" excludes="**/*.java"/>
        </copy>
    </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>
            <path refid="classpath"/>
            <path location="${jar.dir}/${ant.project.name}.jar"/>
        </classpath>
    </target>

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

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

</project>

Ant 运行时出现新错误

运行:

[java] Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/log4j/Logger
 [java]     at org.raxa.module.scheduler.TimeSetter.<clinit>(Unknown Source)
 [java]     at org.raxa.module.loader.LoadServer.main(Unknown Source)
 [java] Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Logger
 [java]     at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
 [java]     at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
 [java]     at java.security.AccessController.doPrivileged(Native Method)
 [java]     at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
 [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
 [java]     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
 [java]     at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
 [java]     ... 2 more
 [java] Java Result: 1

BUILD FAILED
/home/atul/Documents/workspace2/Raxa-4/build.xml:41: Problem: failed to create task or type classpath
Cause: The name is undefined.
Action: Check the spelling.
Action: Check that any custom tasks/types have been declared.
Action: Check that any <presetdef>/<macrodef> declarations have taken pla

Answer 1

也许问题是您的类路径被覆盖了。试试这个:

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