PowerMock again and again initializer error

Question

I am getting this error:

java.lang.ExceptionInInitializerError
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)
    at javassist.runtime.Desc.getClassObject(Desc.java:43)
    at javassist.runtime.Desc.getClassType(Desc.java:152)
    at javassist.runtime.Desc.getType(Desc.java:122)
    at javassist.runtime.Desc.getType(Desc.java:78)
    at mh.scene.terrain.MapReaderTestNew.testAcceptValidFilenames(MapReaderTestNew.java:26)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:68)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:310)
    at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:88)
    at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:96)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:294)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282)
    at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:86)
    at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:120)
    at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:33)
    at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:45)
    at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:122)
    at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:106)
    at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53)
    at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: java.lang.NullPointerException
    at mh.scene.terrain.TMXMapReader.<clinit>(TMXMapReader.java:84)
    ... 36 more

That is a very well known issues. The problem is that I can't find a very well working solution. The code of the test is this:

package mh.scene.terrain;

import static org.easymock.EasyMock.createMock;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

import java.io.File;

import mh.CachedResources;
import mh.scene.entity.player.EntityPlayerLocal;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.easymock.PowerMock;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

@SuppressWarnings("javadoc")
@RunWith(PowerMockRunner.class)
//@PrepareForTest(CachedResources.class)
public class MapReaderTestNew {
    @Test
    public void testAcceptValidFilenames() {
        // Arrange
        TMXMapReader reader = new TMXMapReader();

        // Assert
        assertTrue(reader.accept(new File("example.tmx")));
        assertTrue(reader.accept(new File("/tmp/example.tmx")));
        assertTrue(reader.accept(new File("/tmp/example.tsx")));
        assertTrue(reader.accept(new File("/tmp/example.tmx.gz")));
        assertFalse(reader.accept(new File("/tmp/example.txt")));
        assertFalse(reader.accept(new File("/tmp/example.xml")));
        assertFalse(reader.accept(new File("/tmp/example.exe")));
        assertFalse(reader.accept(new File("/tmp/example")));
    }

    @Test
    public void testReadingMapExample() throws Exception {


        EntityPlayerLocal pl = createMock(EntityPlayerLocal.class);
        Map map = new TMXMapReader().readMap("/sewers.tmx", null, pl);

//      PowerMock.mockStatic(CachedResources.class);
//      PowerMock.replay(CachedResources.class);

        assertEquals(50, map.getHeight());
        assertEquals(50, map.getWidth());
        assertEquals(1, map.getTilesetCount());
        assertEquals(3, map.getLayerCount());
        assertEquals(1, map.getObjectsetCount());
    }
}

That is extremely simple, and even removing the "PowerMock.mockStatic()" the error is present when I add the RunWith

Any Idea?

---

The problem seems to be in this part of code:

File JAR_FILE = (MagicHogwarts.class.getProtectionDomain().getCodeSource().getLocation() == null ? null : new File(MagicHogwarts.class.getProtectionDomain().getCodeSource().getLocation().getPath()));

that returns a null. What is the correct way to handle paths that is testable with powermock? That particular error is thrown only when I use the statement "RunWith"

Answer 1

Try to add this annotation

@SuppressStaticInitializationFor( {"package.YourClass"})  

in order to mock static you need it for powermockito to know that its need to suppress static as part of changing the byte code

Answer 2

You might also need to add the EntityPlayerLocal.class to @PrepareForTest(). The createMock(EntityPlayerLocal.class) method is causing the issue I guess. Can you check the code that is written in it once. It would be better if you can paste that method also in your question.