Ant Javac and Commandline Javac give different results

问题

I have a class that imports some servlet libraries. When I compile it from command-line it is fine.

When I use the ant compile task to compile it, it gives the errors that it can't find the servlet libraries in its path.

Is that a known/common occurrence?

Here is my Ant target:

<target name="compile" depends="prepare" description="compile the source" >
    <echo>=== COMPILE === SRCDIR: ${src}/com/udfr/src/java </echo> <!-- Compile the java code from ${src} into ${build} -->
    <javac srcdir="${src}/com/udfr/src/java" destdir="${dist}/WEB-INF/classes"/>
</target>

回答1:

It's a common occurrence if you don't specify the servlet libraries properly in the classpath for the javac task... I suspect that's the problem. If you post the task which fails and the command line which works, we'll be able to help more.

回答2:

For some reason, the JAR file containing the Servlet API is part of your classpath when you compile your program in command line. However, it's not in the classpath of the javac Ant task.

You should explicitely add the JAR file to the classpath in your javac Ant task. There are several ways to do that; please read http://ant.apache.org/manual/Tasks/javac.html

来源：https://stackoverflow.com/questions/5626317/ant-javac-and-commandline-javac-give-different-results