JMOCK Dependency Issue

Question

I am trying to get through my very first JMOCK tutorial http://www.jmock.org/getting-started.html, and it didn't go well.

The problem I encountered is below:

java.lang.SecurityException: class "org.hamcrest.TypeSafeMatcher"'s signer information does not match signer information of other classes in the same package
    at java.lang.ClassLoader.checkCerts(Unknown Source)
    at java.lang.ClassLoader.preDefineClass(Unknown Source)
    at java.lang.ClassLoader.defineClassCond(Unknown Source)
    at java.lang.ClassLoader.defineClass(Unknown Source)
    at java.security.SecureClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.access$000(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(Unknown Source)
    at java.lang.ClassLoader.defineClass(Unknown Source)
    at java.security.SecureClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.access$000(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at org.jmock.internal.InvocationExpectationBuilder.createExpectationFrom(InvocationExpectationBuilder.java:86)
    at org.jmock.internal.InvocationToExpectationTranslator.invoke(InvocationToExpectationTranslator.java:19)
    at org.jmock.internal.FakeObjectMethods.invoke(FakeObjectMethods.java:38)
    at org.jmock.lib.JavaReflectionImposteriser$1.invoke(JavaReflectionImposteriser.java:33)
    at $Proxy8.receive(Unknown Source)
    at PublisherTest$1.(PublisherTest.java:35)
    at PublisherTest.oneSubscriberReceivesAMessage(PublisherTest.java:34)
    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:66)
    at org.jmock.integration.junit4.JMock$1.invoke(JMock.java:37)
    at org.junit.internal.runners.MethodRoadie.runTestMethod(MethodRoadie.java:105)
    at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:86)
    at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:94)
    at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:84)
    at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49)
    at org.junit.internal.runners.JUnit4ClassRunner.invokeTestMethod(JUnit4ClassRunner.java:96)
    at org.junit.internal.runners.JUnit4ClassRunner.runMethods(JUnit4ClassRunner.java:59)
    at org.junit.internal.runners.JUnit4ClassRunner$1.run(JUnit4ClassRunner.java:52)
    at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
    at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
    at org.junit.internal.runners.JUnit4ClassRunner.run(JUnit4ClassRunner.java:50)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

I've found a solution on the internet. Please see below:

The solution is to ensure that any dependencies on JMock JARs occur before dependencies on JUnit in every plug-in. That way, Hamcrest is loaded from JMock, not from JUnit.

My understanding of the solution is: make the test class use the hamcrest jar from JMock instead of the one from Junit? Am I right? What should I do in Eclipse to make it happen?

Thanks,

Sarah

Answer 1

The libraries order in the Eclipse build configuration are:

hamcrest-core-1.2.jar hamcrest-library-1.2.jar jmock-2.5.1.jar JRE [JavaSE-1.6] JUnit_4.8.1.jar (part of the eclipse distribution) hamcrest.core_1.1.0 (bundled with JUnit 4.8.1)

The solution is simple - make sure that hamcrest.jar is before the JUnit library included by Eclipse in the classpath.

I believe if you look at the "Order and Export" tab in the java build path property (Configure Build Path), you will find that the JUnit jar is above the hamcrest.jar. You can move hamcrest above the JUnit jar here and the problem will go away.

Answer 2

You could use junit-dep.jar (rather than junit.jar) which doesn't include the hamcrest types. Then the hamcrest references in jmock won't clash.

Answer 3

    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit-dep</artifactId>
        <version>4.8.2</version>
        <exclusions>
            <exclusion>
                <groupId>org.hamcrest</groupId>
                <artifactId>hamcrest-core</artifactId>
            </exclusion>
        </exclusions>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.hamcrest</groupId>
        <artifactId>hamcrest-all</artifactId>
        <version>1.3.0RC2</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.jmock</groupId>
        <artifactId>jmock</artifactId>
        <version>2.6.0-RC2</version>
        <exclusions>
            <exclusion>
                <groupId>org.hamcrest</groupId>
                <artifactId>hamcrest-core</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.hamcrest</groupId>
                <artifactId>hamcrest-library</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.hamcrest</groupId>
                <artifactId>hamcrest-unit-test</artifactId>
            </exclusion>
        </exclusions>
        <scope>test</scope>
    </dependency>
    <!-- next libs are optional -->
    <dependency>
        <groupId>org.jmock</groupId>
        <artifactId>jmock-junit3</artifactId>
        <version>2.6.0-RC2</version>
        <exclusions>
            <exclusion>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
            </exclusion>
        </exclusions>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.jmock</groupId>
        <artifactId>jmock-legacy</artifactId>
        <version>2.6.0-RC2</version>
        <scope>test</scope>
    </dependency>

Answer 4

This happened to me due to duplicate JUnit dependencies on the project. One added by eclipse and one from Maven dependencies (m2eclipse/m2e adds this one to classpath as well).

So remove the one added by eclipse to project by going to Project > Properties > Build Path

See below.