注解+动态代理的一个实例.doc

学习下动态代理模式（关于代理的基础只是有很多帖子都有我就不重复了），做了个注解动态代理的例子，给那些学习注解或动态代理的初学者。花了将近1小时，没做个什么优化，大牛勿喷。几个主要的类：注解类：package test2;import java.lang.annotation.ElementType;import java.lang.annotation.Retention;import java.lang.annotation.RetentionPolicy;import java.lang.annotation.Target;Retention(RetentionPolicy.RUNTIME) Target(ElementType.METHOD)public interface ProxyTag public Class proxyClass(); 代理类父类： import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;import java.lang.reflect.Proxy;public abstract class ProxyBean implements InvocationHandlerprivate Object o;private ProxyBean proxyBean;private String methodName;public Object bind(Object obj,ProxyBean proxyBean,String methodName)this.o = obj;xyBean = proxyBean;this.methodName = methodName;return Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(), this);public Object invoke(Object proxy, Method method, Object obj)throws Throwable if(method.getName().equals(methodName)proxyBean.before();Object result = method.invoke(o, obj);proxyBean.after();return result;elseObject result = method.invoke(o, obj);return result;public abstract void before();public abstract void after();代理工厂：import java.lang.reflect.Constructor;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;public class ProxyFactory public static T getProxyBean(Class clazz)T t = (T) newInstance(clazz);Method methods = clazz.getMethods();for(int i=0;imethods.length;i+)ProxyTag pt = methodsi.getAnnotation(ProxyTag.class);if(pt = null)continue;ProxyBean pb = (ProxyBean) newInstance(xyClass();t = (T) pb.bind(t, pb, methodsi.getName();return t;private static Object newInstance(final Class clazz)try Constructor cons = clazz.getConstructor();return cons.newInstance(new Class); catch (SecurityException e) / TODO Auto-generated catch blocke.printStackTrace(); catch (NoSuchMethodException e) / TODO Auto-generated catch blocke.printStackTrace(); catch (IllegalArgumentException e) / TODO Auto-generated catch blocke.printStackTrace(); catch (InstantiationException e) / TODO Auto-generated catch blocke.printStackTrace(); catch (IllegalAccessException e) / TODO Auto-generated catch blocke.printStackTrace(); catch (InvocationTargetException e) / TODO Auto-generated catch blocke.printStackTrace();return null;测试类：package test2;public class ProxyClass extends ProxyBeanpublic void after() System.out.println(after.);public void before() System.out.println(before.);public class ProxyClass2 extends ProxyBeanpublic void after() System.out.println(after2.);public void before() System.out.println(before2.);public interface IDemo public void sayHello();public void sayHello2();public class Demo implements IDemoProxyTag(proxyClass=ProxyClass.class)public void sayHello()System.out.println(hello.);ProxyTag(proxyClass=ProxyClass2.class)public void sayHello2()System.out.println(hello2.); public class Test /* * param args */public static void main(String