Java 动态代理的实现 Java 动态代理的多种实现方式

public interface TargetInterface {
	public void save();
	
	public void print(String str);
}

public class Target implements TargetInterface{
	
	public void save() {
		System.out.println("save running...");
	}
	
	public void print(String str) {
		System.out.println(str);
	}

}

public class Advice {
	public void before() {
		System.out.println("前置增强");
	}

	public void after() {
		System.out.println("后置增强");
	}
}

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

public class ProxyTest {

	public static void main(String[] args) {
		
		//目标对象
		final Target target = new Target();
		
		//增强对象
		final Advice advice = new Advice();
		
		TargetInterface proxyInstance = (TargetInterface)Proxy.newProxyInstance(
				target.getClass().getClassLoader(), 					//目标对象类加载器
				target.getClass().getInterfaces(), 						//目标对象相同的接口字节码对象数组
				new InvocationHandler() {
					//调用代理对象的任何方法，实质执行的都是invoke方法
					public Object invoke(Object proxy, Method method, Object[] args) throws Throwable{
						advice.before();								//前置增强
						Object invoke = method.invoke(target, args);	//执行目标方法
						advice.after();									//后置增强
						System.out.println();
						return invoke;
					}
				});
		
		//代理对象的方法测试
		proxyInstance.save();
		
		proxyInstance.print("JDK动态代理");
	}

}

<dependency>
	<groupId>org.springframework</groupId>
	<artifactId>spring-context</artifactId>
	<version>4.2.4.RELEASE</version>
</dependency>

public class Target {
	public void save() {
		System.out.println("save running...");
	}
	
	public void print(String str) {
		System.out.println(str);
	}
}

public class Advice {
	
	public void before() {
		System.out.println("前置增强");
	}

	public void after() {
		System.out.println("后置增强");
	}

}

import java.lang.reflect.Method;

import org.springframework.cglib.proxy.Enhancer;
import org.springframework.cglib.proxy.MethodInterceptor;
import org.springframework.cglib.proxy.MethodProxy;

public class ProxyTest {

	public static void main(String[] args) {
		final Target target = new Target();
		final Advice advice = new Advice();
		
		//返回值就是动态生成的代理对象，基于cglib
		//创建增强器
		Enhancer enhancer = new Enhancer();
		
		//设置父类（目标）
		enhancer.setSuperclass(Target.class);
		
		//设置回调
		enhancer.setCallback(new MethodInterceptor() {
			public Object intercept(Object o, Method method, Object[] obj, MethodProxy methodProxy) throws Throwable{
				advice.before();
				Object invoke = method.invoke(target, obj);
				advice.after();
				System.out.println();
				return invoke;
			}
		});
		
		//创建代理对象
		Target proxy = (Target)enhancer.create();
		
		//测试代理方法
		proxy.save();
		proxy.print("基于cglib实现动态规划");
		
	}

}