我是新的java，ant和stackoverflow。
我在Windows下的Project_Dir director下有一个build.xml文件并运行＆＃34; ant run＆＃34;命令运行OCI_HelloWorld.java文件，该文件位于＆＃34; src＆＃34;文件夹中。
运行＆＃34; ant run＆＃34;命令。
C:\Project_Dir>ant run
Buildfile: C:\Project_Dir\build.xml
run:
[java] Error: Could not find or load main class OCI_HelloWorld
[java] Java Result: 1
BUILD SUCCESSFUL
Total time: 0 seconds
下面是我的build.xml文件
<!-- define the classpath for building the project -->
<path id="build.classpath">
<!-- include jar files under lib directory -->
<fileset dir="lib" includes="*.jar" />
</path>
<!-- define the classpath for running the project -->
<path id="run.classpath">
<!-- include jar files under lib directory -->
<fileset dir="lib" includes="*.jar" />
<!-- include the jar file resulting from building the project -->
<pathelement path="build/dist/OCI_HelloWorld.jar" />
</path>
<!-- build the jar file for the project -->
<target name="build" description="Build the HelloWorld program">
<!-- first compile your java class code -->
<mkdir dir="build/classes" />
<javac includeantruntime="false" srcdir="src" destdir="build/classes" debug="true" includes="C:\Project_Dir\src\*.java" fork="yes" executable="C:\Program Files\Java\jdk1.7.0_79\bin\javac">
<classpath refid="build.classpath" />
</javac>
<!-- now assemble a jar file from the compiled classes -->
<mkdir dir="build/dist" />
<jar jarfile="build/dist/OCI_HelloWorld.jar" fork="yes" basedir="build/classes">
<fileset dir="build/classes" includes="**/*.*" />
</jar>
</target>
<!-- run the project jar file -->
<target name="run" description="Run the HelloWorld program">
<!-- run java on the resulting code -->
<java classname="OCI_HelloWorld" fork="true" >
<classpath refid="run.classpath" />
</java>
</target>
<!-- reset build environment to starting point -->
<target name="clean" description="Cleans up your project build artifacts">
<delete dir="build" />
</target>
请让我知道我需要做些什么才能摆脱这个错误。