title: Creating a Serializable mock with Mockito error
body: <p>I'm trying to create a mock object with Mockito that can be serialized. The object is an interface implementation. When this method is called, I receive an object that I want to pass to another object, hence using the doAnswer(...)-method.
  This is my code.</p>
  
  <pre><code>InterfaceClass obj = mock(InterfaceClass.class, withSettings().serializable());
      doAnswer(new Answer&lt;Object&gt;() {
          public Object answer(InvocationOnMock invocation) throws Throwable {
              Object[] args = invocation.getArguments();
              //Here I do something with the arguments
          }
      }).when(obj).someMethod(
              any(someObject.class));
  
      ByteArrayOutputStream bos = new ByteArrayOutputStream();
      ObjectOutput out = null;
      try {
        out = new ObjectOutputStream(bos);   
        out.writeObject(obj);
        byte[] yourBytes = bos.toByteArray();
      } finally {
        out.close();
        bos.close();
      }
  </code></pre>
  
  <p>As far as I can tell this should be correct (I'm fairly new to Mockito).
  But when Serializing my object I get this error:</p>
  
  <pre><code>java.io.NotSerializableException: com.trust1t.ocs.signcore.test.InvalidInputTestCase$1
  at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1165)
  at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:329)
  at java.util.concurrent.ConcurrentLinkedQueue.writeObject(ConcurrentLinkedQueue.java:644)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:950)
  at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1482)
  at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413)
  at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159)
  at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535)
  at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
  at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413)
  at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159)
  at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:329)
  at java.util.LinkedList.writeObject(LinkedList.java:943)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:950)
  at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1482)
  at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413)
  at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159)
  at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535)
  at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
  at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413)
  at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159)
  at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535)
  at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
  at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413)
  at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159)
  at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535)
  at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
  at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413)
  at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159)
  at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1535)
  at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
  at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1413)
  at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1159)
  at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:329)
  at com.trust1t.ocs.signcore.test.InvalidInputTestCase.certificateValidationTest(InvalidInputTestCase.java:117)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
  at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
  at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
  at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
  at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
  at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
  at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
  at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
  at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
  at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
  at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
  at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
  at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
  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)
  </code></pre>
  
  <p>The invalidInputTestCase class is the class containing the test where I'm using this code. It looks as if the mock object references this TestCase somewhere (can't find it though). 
  Am I not correctly implementing this or better ideas to mock? </p>