NoClassDefFoundError当编译和运行与蚂蚁

Question

我想编译和运行使用Ant的项目，我得到一个NoClassDefFoundError。这是位于src文件夹我OutlookToGmailCalendarSync.java文件：

package sample.calendar; 
public class OutlookToGmailCalendarSync { 
    public static void main(String[] args) { 
     System.out.println("hi"); 
    } 
} 

这是我的build.xml文件：

<project name="MyCalendarSample" default="run" basedir="."> 
<description> 
    simple example build file 
</description> 
<!-- set global properties for this build --> 
<property name="src" location="src"/> 
<property name="build" location="build"/> 
<property name="dist" location="dist"/> 

<path id="path.class"> 
    <pathelement location="build/sample/calendar"/> 
</path> 

<target name="run" depends="compile" 
    description="Runs the complied project"> 
    <!-- Run --> 
    <java fork="true" classname="OutlookToGmailCalendarSync"> 
    <classpath> 
    <path refid="path.class"/> 
    </classpath> 
</java> 
</target> 

<target name="compile" depends="init" 
    description="compile the source " > 
    <!-- Compile the java code from ${src} into ${build} --> 
    <javac srcdir="${src}" destdir="${build}"/> 
</target> 

<target name="init"> 
    <!-- Create the time stamp --> 
    <tstamp/> 
    <!-- Create the build directory structure used by compile --> 
    <mkdir dir="${build}"/> 
</target> 

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

</project> 

这是结果：

C:\java\my>ant 
Buildfile: C:\java\my\build.xml 

init: 

compile: 
    [javac] C:\java\my\build.xml:30: warning: 'includeantruntime' was not set, d 
efaulting to build.sysclasspath=last; set to false for repeatable builds 
    [javac] Compiling 1 source file to C:\java\my\build 

run: 
    [java] java.lang.NoClassDefFoundError: OutlookToGmailCalendarSync (wrong na 
me: sample/calendar/OutlookToGmailCalendarSync) 
    [java]  at java.lang.ClassLoader.defineClass1(Native Method) 
    [java]  at java.lang.ClassLoader.defineClass(ClassLoader.java:791) 
    [java]  at java.security.SecureClassLoader.defineClass(SecureClassLoader 
.java:142) 
    [java]  at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) 
    [java]  at java.net.URLClassLoader.access$100(URLClassLoader.java:71) 
    [java]  at java.net.URLClassLoader$1.run(URLClassLoader.java:361) 
    [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]  at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.j 
ava:482) 
    [java] Exception in thread "main" 
    [java] Java Result: 1 

BUILD SUCCESSFUL 
Total time: 1 second 

C:\java\my> 

即使经过阅读其他论坛帖子，我仍然不明白为什么这发生在我身上。在运行时，编译的类位于build/sample/calendar中，这是classpath设置的，所以我没有看到问题。

Answer 1

尝试使用以下的变化：

类路径被设置为其中的类生成并提供了一种用于java命令类的打包名称的根目录。

<path id="path.class"> 
<pathelement location="build"/> 
</path> 

<target name="run" depends="compile" 
description="Runs the complied project"> 
<!-- Run --> 
<java fork="true" classname="sample.calendar.OutlookToGmailCalendarSync" > 
<classpath refid="path.class"/> 
</java> 
</target> 

希望这会有所帮助。