动态代理工厂类

[huangxw000]

import java.lang.reflect.InvocationHandler;  
import java.lang.reflect.Proxy;  
public abstract class JdkProxyFactoryUtils {  
  
    public static Object wrap(InvocationHandlerWrapper hander) {  
    Class<?> clazz = hander.getBean().getClass();  
    return Proxy.newProxyInstance(clazz.getClassLoader(),  
        clazz.getInterfaces(), hander);  
    }  
} 

import java.lang.reflect.InvocationHandler;  
import java.lang.reflect.Method;  
  
public abstract class InvocationHandlerWrapper implements InvocationHandler {  
    private Object object = null;  
  
    public InvocationHandlerWrapper(Object object) {  
    super();  
    this.object = object;  
    }  
  
    public Object getBean() {  
    return object;  
    }  
  
    abstract public Object invoke(Object proxy, Method method, Object[] args)  
        throws Throwable;  
  
}  

测试代码，定义一个过滤器，对HttpServletRequest和HttpServletResponse包装，实现输出调用的方法的名称。

package com.mvc.filter;

import java.io.IOException;
import java.lang.reflect.Method;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.mvc.common.InvocationHandlerWrapper;
import com.mvc.common.JdkProxyFactoryUtils;

public class ProxyFilter implements Filter {

    @Override
    public void destroy() {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
	    FilterChain chain) throws IOException, ServletException {
	HttpServletRequest req = (HttpServletRequest) request;
	HttpServletResponse resp = (HttpServletResponse) response;
	HttpServletRequest httpServletRequestWrapper = (HttpServletRequest) JdkProxyFactoryUtils
		.wrap(new InvocationHandlerWrapper(req) {
		    @Override
		    public Object invoke(Object proxy, Method method,
			    Object[] args) throws Throwable {
			Object result = method.invoke(this.getBean(), args);
			System.out.println(method.getName());
			return result;
		    }
		});
	HttpServletResponse httpServletResponseWrapper = (HttpServletResponse) JdkProxyFactoryUtils
		.wrap(new InvocationHandlerWrapper(resp) {
		    @Override
		    public Object invoke(Object proxy, Method method,
			    Object[] args) throws Throwable {
			Object result = method.invoke(this.getBean(), args);
			System.out.println(method.getName());
			return result;
		    }
		});
	chain.doFilter(httpServletRequestWrapper, httpServletResponseWrapper);
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {

    }

}