java动态代理的应用——动力节点.docx

动态代理其实就是java.lang.reflect.Proxy类动态的根据您指定的所有接口生成一个class byte，该class会继承Proxy类，并实现所有你指定的接口（您在参数中传入的接口数组）；然后再利用您指定的classloader将 class byte加载进系统，最后生成这样一个类的对象，并初始化该对象的一些值，如invocationHandler,以即所有的接口对应的Method成员。 初始化之后将对象返回给调用的客户端。这样客户端拿到的就是一个实现你所有的接口的Proxy对象。请看实例分析：代码如下package xy; public interface BusinessProcessor { public void processBusiness();} 代码如下package xy;/** * 业务处理类 * @author fanshadoop * */public class BusinessProcessorImpl implements BusinessProcessor { @Override public void processBusiness() { System.out.println(processing business.....); } }代码如下package xy; import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;/** * 业务代理类 * @author fanshadoop * */public class BusinessProcessorHandler implements InvocationHandler { private Object target = null; BusinessProcessorHandler(Object target) { this.target = target; } public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { System.out .println(You can do something here before process your business); Object result = method.invoke(target, args); System.out .println(You can do something here after process your business); return result; } }代码如下package xy; import java.lang.reflect.Field;import java.lang.reflect.Method;import java.lang.reflect.Modifier;import java.lang.reflect.Proxy; public class Test { /** * @param args */ public static void main(String[] args) { BusinessProcessorImpl bpimpl = new BusinessProcessorImpl(); BusinessProcessorHandler handler = new BusinessProcessorHandler(bpimpl); BusinessProcessor bp = (BusinessProcessor) Proxy.newProxyInstance( bpimpl.getClass().getClassLoader(), bpimpl.getClass() .getInterfaces(), handler); cessBusiness(); System.out.println(bp.getClass().getName()); printClassDefinition(bp.getClass()); } public static String getModifier(int modifier) { String result = ; switch (modifier) { case Modifier.PRIVATE: result = private; case Modifier.PUBLIC: result = public; case Modifier.PROTECTED: result = protected; case Modifier.A