How to set a long Java classpath in Windows?

java junit classpath
Ogre Psalm33 picture Ogre Psalm33 · Oct 14, 2008 · Viewed 69.6k times · Source

I'm trying to run a particular JUnit test by hand on a Windows XP command line, which has an unusually high number of elements in the class path. I've tried several variations, such as:

set CLASS_PATH=C:\path\a\b\c;C:\path\e\f\g;....
set CLASS_PATH=%CLASS_PATH%;C:\path2\a\b\c;C:\path2\e\f\g;....
...
C:\apps\jdk1.6.0_07\bin\java.exe -client oracle.jdevimpl.junit.runner.TestRunner com.myco.myClass.MyTest testMethod

(Other variations are setting the classpath all on one line, setting the classpath via -classpath as an argument to java"). It always comes down to the console throwing up it's hands with this error:

The input line is too long.
The syntax of the command is incorrect.

This is a JUnit test testing a rather large existing legacy project, so no suggestions about rearranging my directory structure to something more reasonable, those types of solutions are out for now. I was just trying to gen up a quick test against this project and run it on the command line, and the console is stonewalling me. Help!

Answer

Chris Noe picture Chris Noe · Oct 14, 2008

The Windows command line is very limiting in this regard. A workaround is to create a "pathing jar". This is a jar containing only a Manifest.mf file, whose Class-Path specifies the disk paths of your long list of jars, etc. Now just add this pathing jar to your command line classpath. This is usually more convenient than packaging the actual resources together.

As I recall, the disk paths can be relative to the pathing jar itself. So the Manifest.mf might look something like this:

Class-Path: this.jar that.jar ../lib/other.jar

If your pathing jar contains mainly foundational resources, then it won't change too frequently, but you will probably still want to generate it somewhere in your build. For example:

<jar destfile="pathing.jar">
  <manifest>
    <attribute name="Class-Path" value="this.jar that.jar ../lib/other.jar"/>
  </manifest>
</jar>

Related questions

Ant + JUnit: NoClassDefFoundError

Ok, I'm frustrated! I've hunted around for a good number of hours and am still stumped. Environment: WinXP, Eclipse Galileo 3.5 (straight install - no extra plugins). So, I have a simple JUnit test. It runs fine from it's internal Eclipse …

Read More
How do you assert that a certain exception is thrown in JUnit 4 tests?

How can I use JUnit4 idiomatically to test that some code throws an exception? While I can certainly do something like this: @Test public void testFooThrowsIndexOutOfBoundsException() { boolean thrown = false; try { foo.doStuff(); } catch (IndexOutOfBoundsException e) { thrown = true; } assertTrue(thrown); } I …

Read More
Mockito : how to verify method was called on an object created within a method?

I am new to Mockito. Given the class below, how can I use Mockito to verify that someMethod was invoked exactly once after foo was invoked? public class Foo { public void foo(){ Bar bar = new Bar(); bar.someMethod(); } } I would …

Read More