Spring Framework example source code file (ReflectiveLoadTimeWeaverTests.java)

This example Spring Framework source code file (ReflectiveLoadTimeWeaverTests.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 - Spring Framework tags/keywords

classfiletransformer, classloader, classloader, exception, exception, justaddtransformerclassloader, justaddtransformerclassloader, protectiondomain, reflectiveloadtimeweaver, reflectiveloadtimeweaver, reflectiveloadtimeweavertests, security, string, testcase, totallycompliantclassloader

The Spring Framework ReflectiveLoadTimeWeaverTests.java source code

/*
 * Copyright 2002-2006 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.instrument.classloading;

import junit.framework.TestCase;
import org.springframework.test.AssertThrows;

import java.lang.instrument.ClassFileTransformer;
import java.security.ProtectionDomain;

/**
 * Unit tests for the {@link ReflectiveLoadTimeWeaver} class.
 *
 * @author Rick Evans
 */
public final class ReflectiveLoadTimeWeaverTests extends TestCase {

	public void testCtorWithNullClassLoader() throws Exception {
		new AssertThrows(IllegalArgumentException.class) {
			public void test() throws Exception {
				new ReflectiveLoadTimeWeaver(null);
			}
		}.runTest();
	}

	public void testCtorWithClassLoaderThatDoesNotExposeAnAddTransformerMethod() throws Exception {
		new AssertThrows(IllegalStateException.class) {
			public void test() throws Exception {
				new ReflectiveLoadTimeWeaver(getClass().getClassLoader());
			}
		}.runTest();
	}

	public void testCtorWithClassLoaderThatDoesNotExposeAGetThrowawayClassLoaderMethodIsOkay() throws Exception {
		JustAddTransformerClassLoader classLoader = new JustAddTransformerClassLoader();
		ReflectiveLoadTimeWeaver weaver = new ReflectiveLoadTimeWeaver(classLoader);
		weaver.addTransformer(new ClassFileTransformer() {
			public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) {
				return "CAFEDEAD".getBytes();
			}
		});
		assertEquals(1, classLoader.getNumTimesGetThrowawayClassLoaderCalled());
	}

	public void testAddTransformerWithNullTransformer() throws Exception {
		new AssertThrows(IllegalArgumentException.class) {
			public void test() throws Exception {
				new ReflectiveLoadTimeWeaver(new JustAddTransformerClassLoader()).addTransformer(null);
			}
		}.runTest();
	}

	public void testGetThrowawayClassLoaderWithClassLoaderThatDoesNotExposeAGetThrowawayClassLoaderMethodYieldsFallbackClassLoader() throws Exception {
		ReflectiveLoadTimeWeaver weaver = new ReflectiveLoadTimeWeaver(new JustAddTransformerClassLoader());
		ClassLoader throwawayClassLoader = weaver.getThrowawayClassLoader();
		assertNotNull(throwawayClassLoader);
	}

	public void testGetThrowawayClassLoaderWithTotallyCompliantClassLoader() throws Exception {
		TotallyCompliantClassLoader classLoader = new TotallyCompliantClassLoader();
		ReflectiveLoadTimeWeaver weaver = new ReflectiveLoadTimeWeaver(classLoader);
		ClassLoader throwawayClassLoader = weaver.getThrowawayClassLoader();
		assertNotNull(throwawayClassLoader);
		assertEquals(1, classLoader.getNumTimesGetThrowawayClassLoaderCalled());
	}


	public static class JustAddTransformerClassLoader extends ClassLoader {

		private int numTimesAddTransformerCalled = 0;


		public int getNumTimesGetThrowawayClassLoaderCalled() {
			return this.numTimesAddTransformerCalled;
		}


		public void addTransformer(ClassFileTransformer transformer) {
			++this.numTimesAddTransformerCalled;
		}

	}


	public static final class TotallyCompliantClassLoader extends JustAddTransformerClassLoader {

		private int numTimesGetThrowawayClassLoaderCalled = 0;


		public int getNumTimesGetThrowawayClassLoaderCalled() {
			return this.numTimesGetThrowawayClassLoaderCalled;
		}


		public ClassLoader getThrowawayClassLoader() {
			++this.numTimesGetThrowawayClassLoaderCalled;
			return getClass().getClassLoader();
		}

	}

}