Mocking a URL in Java

Question

We have a URL object in one of our Java classes that we want to mock, but it\'s a final class so we cannot. We do not want to go a level above, and mock the InputStream beca

Answer 1

JMockit does indeed allow you to mock a final JRE class like java.net.URL.

It seems the Attach API in jdkDir/lib/tools.jar available in implementations of JDK 1.6 other than Sun's does not work as well. I guess this stuff is still too new/advanced, or simply didn't get the necessary attention from the other JDK vendors (Apple, IBM with the J9 JDK, Oracle with the JRockit JDK).

So, if you run into problems by having tools.jar in the classpath, try using the "-javaagent:jmockit.jar" JVM argument. It tells the JVM to directly load the java agent at startup, without using the Attach API. That should work in the Apple JDK 1.5/1.6.