java中的动态代理与责任链模式详解

package com.mzs.test;
public interface DemoService {
    void speak(String str);
    void jump(String str);
}

package com.mzs.test;
public class DemoServiceImpl implements DemoService {
    public void speak(String string) {
        System.out.println("hello " + string);
    }
    public void jump(String string) {
        System.out.println("hi " + string);
    }
}

package com.mzs.test;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
public class TestProxy implements InvocationHandler {
    private Object target;
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        return method.invoke(target, args);
    }
    public Object bind(Object target) {
        this.target = target;
        return Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(), this);
    }
}

package com.mzs.test;
public class TestProxyDemo {
    public static void main(String[] args) {
        TestProxy instance = new TestProxy();
        DemoService proxy = (DemoService) instance.bind(new DemoServiceImpl());
        proxy.speak("tom");
    }
}

package com.mzs.test;
public class DemoServiceImpl {
    public void speak(String string) {
        System.out.println("hello " + string);
    }
    public void jump(String string) {
        System.out.println("hi " + string);
    }
}

package com.mzs.test;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.Method;
public class TestProxy implements MethodInterceptor {
    /**
     * 代理逻辑方法
     *
     * @param o 代理对象
     * @param method 方法
     * @param objects 方法参数
     * @param methodProxy 代理方法
     * @return 方法返回值
     * @throws Throwable 异常
     */
    @Override
    public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
        return methodProxy.invokeSuper(o, objects);
    }
    /**
     * 生成代理对象
     *
     * @param cls 被代理的Class对象
     * @return 代理对象
     */
    public Object bind(Class cls) {
        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(cls);
        enhancer.setCallback(this);
        return enhancer.create();
    }
}

package com.mzs.test;
public class TestProxyDemo {
    public static void main(String[] args) {
        TestProxy instance = new TestProxy();
        DemoServiceImpl proxy = (DemoServiceImpl) instance.bind(DemoServiceImpl.class);
        proxy.jump("tom");
        proxy.speak("selina");
    }
}

<!-- cglib proxy -->
<dependency>
  <groupId>cglib</groupId>
  <artifactId>cglib</artifactId>
  <version>2.2.2</version>
</dependency>
<dependency>
  <groupId>asm</groupId>
  <artifactId>asm</artifactId>
  <version>3.3</version>
</dependency>

package com.mzs.testThread1;
public interface UserService {
	void speak(String str);
}
package com.mzs.testThread1;
public class UserServiceImpl implements UserService {
	@Override
	public void speak(String str) {
		System.out.println(str);
	}
}

package com.mzs.testThread1;
import java.lang.reflect.Method;
public class MyInterceptor implements Interceptor {
	@Override
	public boolean before(Object proxy, Object target, Method method, Object[] args) {
		System.out.println("反射方法前逻辑1");
		return true;
	}
	@Override
	public void around(Object proxy, Object target, Method method, Object[] args) {
		System.out.println("取代被代理对象的方法");
	}
	@Override
	public void after(Object proxy, Object target, Method method, Object[] args) {
		System.out.println("反射方法后逻辑1");
	}
}

package com.mzs.testThread1;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
public class InterceptorProxy implements InvocationHandler {
	private Object target;
	private Interceptor interceptor;
	public InterceptorProxy(Object target, Interceptor interceptor) {
		this.target = target;
		this.interceptor = interceptor;
	}
	public static Object bind(Object target, Interceptor interceptor) {
		return Proxy.newProxyInstance(target.getClass().getClassLoader(), target.getClass().getInterfaces(), new InterceptorProxy(target, interceptor));
	}
	@Override
	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
		Object result = null;
		if (interceptor == null)
			result = method.invoke(target, args);
		if (interceptor.before(proxy, target, method, args)) 
			result = method.invoke(target, args);
		else 
			interceptor.around(proxy, target, method, args);
		interceptor.after(proxy, target, method, args);
		return result;
	}
}

package com.mzs.testThread1;
public class TestDemo {
	public static void main(String[] args) {
		UserService proxy1 = (UserService) InterceptorProxy.bind(new UserServiceImpl(), new MyInterceptor());
		UserService proxy2 = (UserService) InterceptorProxy.bind(proxy1, new MyInterceptor2());
		UserService proxy3 = (UserService) InterceptorProxy.bind(proxy2, new MyInterceptor3());
		proxy3.speak("hello");
	}
}