Hibernate example source code file (InterceptFieldClassFileTransformerTest.java)

This example Hibernate source code file (InterceptFieldClassFileTransformerTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

arraylist, arraylist, class, exception, instrumentedclassloader, instrumentedclassloader, interceptfieldclassfiletransformertest, interceptfieldclassfiletransformertest, list, method, nosuchmethodexception, nosuchmethodexception, reflection, testcase, util

The Hibernate InterceptFieldClassFileTransformerTest.java source code

//$Id$
package org.hibernate.ejb.test.instrument;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import junit.framework.TestCase;

/**
 * @author Emmanuel Bernard
 * @author Hardy Ferentschik
 */
public class InterceptFieldClassFileTransformerTest extends TestCase {
	/**
	 * Tests that class file enhancement works.
	 * 
	 * @throws Exception in case the test fails.
	 */
	public void testEnhancement() throws Exception {
		List<String> entities = new ArrayList();
		entities.add( "org.hibernate.ejb.test.instrument.Simple" );

		// sanity check that the class is unmodified and does not contain getFieldHandler()
		try {
			org.hibernate.ejb.test.instrument.Simple.class.getDeclaredMethod( "getFieldHandler" );
			fail();
		} catch ( NoSuchMethodException nsme ) {
			// success
		}

		// use custom class loader which enhances the class
		InstrumentedClassLoader cl = new InstrumentedClassLoader( Thread.currentThread().getContextClassLoader() );
		cl.setEntities( entities );
		Class clazz = cl.loadClass( entities.get( 0 ) );
		
		// javassist is our default byte code enhancer. Enhancing will eg add the method getFieldHandler()
		// see org.hibernate.bytecode.internal.javassist.FieldTransformer
		Method method = clazz.getDeclaredMethod( "getFieldHandler" );
		assertNotNull( method );
	}
}