import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;public class DynamicProxy implements InvocationHandler {private Target target;public DynamicProxy(Target target) {this.target = target;}@Overridepublic Object invoke(Object proxy, Method method, Object[] args)throws Throwable {System.out.println("before the work");method.invoke(target, args);System.out.println("after the work");return null;}public Target getProxy() {Class<?>[] interfaces = this.target.getClass().getInterfaces();if (interfaces == null || interfaces.length == 0) {interfaces = new Class<?>[] { Target.class };}Target proxy = (Target) Proxy.newProxyInstance(this.target.getClass().getClassLoader(), interfaces, this);return proxy;}public static void main(String[] args) {Target target = new TargetImpl();new DynamicProxy(target).getProxy().sayHello();}}interface Target {public void sayHello();
}class TargetImpl implements Target {public void sayHello() {System.out.println("hello world");}
}

import java.lang.reflect.Method;import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;public class TestCglibProxy {public static void main(String[] args) {Target target = new Target();TestCglibProxy testCglibProxy = new TestCglibProxy();Target targetProxy = (Target) testCglibProxy.createProxy(target.getClass());targetProxy.sayHello();}public Object createProxy(Class targetClass) {Enhancer enhancer = new Enhancer();enhancer.setSuperclass(targetClass);enhancer.setCallback(new MethodInteceptor());return enhancer.create();}
}class MethodInteceptor implements MethodInterceptor {@Overridepublic Object intercept(Object object, Method method, Object[] arg2,MethodProxy methodProxy) throws Throwable {System.out.println("start to do the work");Object result = methodProxy.invokeSuper(object, arg2);System.out.println("end:do the work");return "haha";}
}class Target {public void sayHello() {System.out.println("hello world");}
}