PowerMockito (with Mockito) failing with ExceptionInInitializerError

Question

We are using Powermockito with Mockito to mock some static classes. There seems to be java.lang.ExceptionInInitializerError thrown every time.

Can you help me identify where the problem is?

Java class under test

package com.myproject.myproduct.search.domain;
import org.elasticsearch.index.query.MultiMatchQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;

public class MyQueryBuilder {

    public MultiMatchQueryBuilder getMultiMatchQueryBuilder() {
        MultiMatchQueryBuilder builder = QueryBuilders.multiMatchQuery("term", "field1");
        builder.field("field1",200.9f);
        return builder;
    }
}

Junit test with Powermock runner

package com.myproject.myproduct.search.domain;

import org.elasticsearch.index.query.MultiMatchQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

@RunWith(PowerMockRunner.class)
@PrepareForTest(QueryBuilders.class)
public class MyQueryBuilderTest {

    private MyQueryBuilder myQueryBuilder;

    @Test
    public void test() {
        PowerMockito.mockStatic(QueryBuilders.class);
        MultiMatchQueryBuilder builder = PowerMockito.mock(MultiMatchQueryBuilder.class);
    }
}

That's it. The test code does not work as soon as I try to mock MultiMatchQueryBuilder.

This is the Exception:

java.lang.ExceptionInInitializerError at org.elasticsearch.common.logging.DeprecationLogger.(DeprecationLogger.java:138) at org.elasticsearch.common.ParseField.(ParseField.java:35) at org.elasticsearch.index.query.AbstractQueryBuilder.(AbstractQueryBuilder.java:53) at sun.reflect.GeneratedSerializationConstructorAccessor7.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.objenesis.instantiator.sun.SunReflectionFactoryInstantiator.newInstance(SunReflectionFactoryInstantiator.java:40) at org.objenesis.ObjenesisBase.newInstance(ObjenesisBase.java:59) at org.mockito.internal.creation.jmock.ClassImposterizer.createProxy(ClassImposterizer.java:128) at org.mockito.internal.creation.jmock.ClassImposterizer.imposterise(ClassImposterizer.java:63) at org.powermock.api.mockito.internal.mockcreation.MockCreator.createMethodInvocationControl(MockCreator.java:111) at org.powermock.api.mockito.internal.mockcreation.MockCreator.mock(MockCreator.java:60) at org.powermock.api.mockito.PowerMockito.mock(PowerMockito.java:143) at com.spartasystems.stratas.search.domain.MyQueryBuilderTest.testBoostSetProperly(MyQueryBuilderTest.java:22) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) 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$1.run(PowerMockJUnit44RunnerDelegateImpl.java:120) at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:33) at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:45) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:122) at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:104) at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53) at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:53) at org.junit.runner.JUnitCore.run(JUnitCore.java:160) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68) at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47) at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242) at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70) Caused by: java.lang.NullPointerException at org.elasticsearch.Build.(Build.java:47) ... 41 more

Process finished with exit code 255

Note:

The source code of actual underlying elasticsearch classes can be found here

https://github.com/elastic/elasticsearch/blob/master/core/src/main/java/org/elasticsearch/index/query/QueryBuilders.java

and

https://github.com/elastic/elasticsearch/blob/master/core/src/main/java/org/elasticsearch/index/query/MultiMatchQueryBuilder.java

Answer 1

When calling with mocks org.elasticsearch.Build#getElasticsearchCodebase

Build.class.getProtectionDomain().getCodeSource().getLocation()

returns null because the code has no location (Dynamic method generated by cglib.)

So when initializing org.elasticsearch.Build during your mock code using

final URL url = getElasticsearchCodebase(); // url is null
final String urlStr = url.toString(); // null pointer exception.

Of course, the mock will not success and throw ExceptionInInitializerError which indicates an exception occurred during evaluation of a static initializer or the initializer for a static variable.

---

You can easily reproduce this exception using following code:

@RunWith(PowerMockRunner.class)
@PrepareForTest({QueryBuilders.class})
public class MyQueryBuilderTest {

    @Test
    public void test() {
        final Build current = Build.CURRENT;
    }

}