Spring Framework example source code file (LockMixin.java)

This example Spring Framework source code file (LockMixin.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

delegatingintroductioninterceptor, lockable, lockedexception, lockedexception, lockmixin, lockmixin, object, object, throwable, throwable

The Spring Framework LockMixin.java source code

/*
 * Copyright 2002-2005 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.aop.framework;

import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.support.DelegatingIntroductionInterceptor;


/**
 * Mixin to provide stateful locking functionality.
 * Test/demonstration of AOP mixin support rather than a
 * useful interceptor in its own right.
 * 
 * @author Rod Johnson
 * @since 10.07.2003
 */
public class LockMixin extends DelegatingIntroductionInterceptor implements Lockable {
	
	/** This field demonstrates additional state in the mixin */
	private boolean locked;
	
	public void lock() {
		this.locked = true;
	}
	
	public void unlock() {
		this.locked = false;
	}

	/**
	 * @see org.springframework.aop.framework.AopProxyTests.Lockable#locked()
	 */
	public boolean locked() {
		return this.locked;
	}

	/**
	 * Note that we need to override around advice.
	 * If the method is a setter and we're locked, prevent execution.
	 * Otherwise let super.invoke() handle it, and do normal
	 * Lockable(this) then target behaviour.
	 * @see org.aopalliance.MethodInterceptor#invoke(org.aopalliance.MethodInvocation)
	 */
	public Object invoke(MethodInvocation invocation) throws Throwable {
		if (locked() && invocation.getMethod().getName().indexOf("set") == 0)
			throw new LockedException();
		return super.invoke(invocation);
	}

}