过滤器Filter(2)

package com.gqx.discussFilter;

import java.io.IOException;

import java.lang.reflect.InvocationHandler;

import java.lang.reflect.Method;

import java.lang.reflect.Proxy;

import java.util.ArrayList;

import java.util.List;

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;

/**

 * 无效数据过滤

 * @author Jie.Yuan

 *

 */

public class DataFilter implements Filter {

     

    // 初始化无效数据

    private List<String> dirtyData;

    @Override

    public void init(FilterConfig filterConfig) throws ServletException {

        // 模拟几个数据

        dirtyData = new ArrayList<String>();

        dirtyData.add("NND");

        dirtyData.add("滚蛋");

    }

    @Override

    public void doFilter(ServletRequest req, ServletResponse res,

            FilterChain chain) throws IOException, ServletException {

         

        // 转型

        final HttpServletRequest request = (HttpServletRequest) req;   

        HttpServletResponse response = (HttpServletResponse) res;

         

        // 一、处理公用业务

        request.setCharacterEncoding("UTF-8");                  // POST提交有效

        response.setContentType("text/html;charset=UTF-8");

         

        HttpServletRequest proxy =  (HttpServletRequest) Proxy.newProxyInstance(

                request.getClass().getClassLoader(),        // 指定当前使用的累加载器

                new Class[]{HttpServletRequest.class},      // 对目标对象实现的接口类型

                new InvocationHandler() {                   // 事件处理器

                    @Override

                    public Object invoke(Object proxy, Method method, Object[] args)

                            throws Throwable {

                        // 定义方法返回值

                        Object returnValue = null;

                        // 获取方法名

                        String methodName = method.getName();

                         

                        // 判断：对getParameter方法进行GET提交中文处理

                        if ("getParameter".equals(methodName)) {

                             

                            // 获取请求数据值【 <input type="text" name="userName">】

                            String value = request.getParameter(args[0].toString());    // 调用目标对象的方法

                             

                            // 获取提交方式

                            String methodSubmit = request.getMethod(); // 直接调用目标对象的方法

                             

                            // 判断如果是GET提交，需要对数据进行处理  (POST提交已经处理过了)

                            if ("GET".equals(methodSubmit)) {

                                if (value != null && !"".equals(value.trim())){

                                    // 处理GET中文

                                    value = new String(value.getBytes("ISO8859-1"),"UTF-8");   

                                }

                            }

                             

                            // 中文数据已经处理完： 下面进行无效数据过滤  

                            //【如何value中出现dirtyData中数据，用****替换】

                            System.out.println("jj");

                            for (String data : dirtyData) {

                                System.out.println("dd");

                                // 判断当前输入数据(value), 是否包含无效数据

                                if (value.contains(data)){

                                    value = value.replace(data, "*****");

                                }

                            }

                            // 处理完编码、无效数据后的正确数据

                            return value;

                        }

                        else {

                            // 执行request对象的其他方法

                            returnValue = method.invoke(request, args);

                        }

                         

                        return returnValue;

                    }

                });

         

        // 二、放行 (执行下一个过滤器或者servlet)

        chain.doFilter(proxy, response);        // 传入代理对象

    }

    @Override

    public void destroy() {

         

    }

}