Beginning of a mock framework for java 1.4.2

AnyMock.java

package unittest.fixture;

public interface AnyMock {
       public String getName();
       public void setName(String value);

       public String printName();
}

Factory.java

package unittest.fixture;
import java.lang.reflect.*;
import java.util.HashMap;

public class Factory implements InvocationHandler {

   protected Class[] interfaces;
   protected Object returnValue;
   protected HashMap returnValues;

   protected Factory(Class[] interfaces) {
       this.returnValues = new HashMap();
       this.interfaces = interfaces;
   }

   public static Factory MockFor(Class[] interfaces) {
       return new Factory(interfaces);
   }

   public Factory returns(Object value) {
       this.returnValue = value;
       return this;
   }

   public Factory forMethod(String methodName) {
       this.returnValues.put(methodName, returnValue);
       returnValue = null;
       return this;
   }

   public Object Build() {
       return Proxy.newProxyInstance(this.getClass().getClassLoader(), interfaces, this);
   }

   public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
       String methodName = method.getName();
       if (returnValues.containsKey(methodName)) return returnValues.get(methodName);
       if (methodName.startsWith("get")) return returnValues.get(propertyName(methodName, "get"));
       if (methodName.startsWith("set")) {
           returnValues.put(propertyName(methodName, "set"), args[0]);
           return null;
       }
       return null;
   }

   private String propertyName(String methodName, String stripWord) {
       return methodName.substring(methodName.indexOf(stripWord) + stripWord.length());
   }
}

FactoryTest.java

package unittest.fixture;

import junit.framework.TestCase;
import junit.framework.Assert;
import unittest.fixture.AnyMock;

/* 
*
public interface AnyMock {
       public String getName();
       public void setName(String value);

       public String printName();
}
*/

public class FactoryTest extends TestCase {

   protected void setUp() throws Exception {
       super.setUp();
   }

   protected void tearDown() throws Exception {
       super.tearDown();
   }

   public void test_stores_returnValues() {
       AnyMock mock = (AnyMock) Factory.MockFor(new Class[] { AnyMock.class })
        .returns("John")
        .forMethod("printName")
        .Build();
       Assert.assertEquals("John", mock.printName());
   }

   public void test_returns_null_for_unimplemented_methods() {
       AnyMock mock = (AnyMock) Factory.MockFor(new Class[] { AnyMock.class }).Build();
       Assert.assertNull(mock.printName());
   }

   public void test_automatic_property_getter_setter_when_none_supplied() {
       AnyMock mock = (AnyMock) Factory.MockFor(new Class[] { AnyMock.class }).Build();
       mock.setName("John");
       Assert.assertEquals("John", mock.getName());
   }
}