Tomcat 5/6 utf-8 编码下完美解决(post/get)中文表单问题的过滤器

1.过滤器 (包含get与post方式)SetCharacterEncodingFilter.java

package com.qingfeng.filter;

import java.io.IOException;
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.UnavailableException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

public class SetCharacterEncodingFilter implements Filter {
     /**
     *
     * 对 HttpServletRequestWrapper 进行扩充, 不影响原来的功能并能提供所有的 HttpServletRequest
     * 接口中的功能. 它可以统一的对 Tomcat 默认设置下的中文问题进行解决而只需要用新的 Request 对象替换页面中的
     * request 对象即可.
     */
    protected String encoding = null;
    protected FilterConfig filterConfig = null;
    //protected boolean ignore = true;

    public void destroy() {
        this.encoding = null;
        this.filterConfig = null;
    }
    
    class Request extends HttpServletRequestWrapper {

        public Request(HttpServletRequest request) {
            super(request);
        }
        /**
         * 转换由表单读取的数据的内码.
         * 从 ISO 字符转到 utf-8(或gbk).
         */
        public String toChi(String input) {
            try {
                
              byte[] bytes = input.getBytes("ISO-8859-1");
              return new String(bytes, encoding);
            }
            catch (Exception ex) {
            }
            return null;
        }

        /**
         * Return the HttpServletRequest holded by this object.
         */
        private HttpServletRequest getHttpServletRequest()
        {
            return (HttpServletRequest)super.getRequest();
        }

        /**
         * 读取参数 -- 修正了中文问题.
         */
        public String getParameter(String name)
        {
            return toChi(getHttpServletRequest().getParameter(name));
        }

        /**
         * 读取参数列表 - 修正了中文问题.
         */
        public String[] getParameterValues(String name)
        {
              String values[] = getHttpServletRequest().getParameterValues(name);
              if (values != null) {
                for (int i = 0; i < values.length; i++) {
                  values[i] = toChi(values[i]);
                }
              }
              return values;
        }
    }
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
        throws IOException, ServletException {


       // if (ignore || (request.getCharacterEncoding() == null)) {
       //     String encoding = selectEncoding(request);
            /*if (encoding != null)
                request.setCharacterEncoding(encoding);*/
       // }
        HttpServletRequest httpreq = (HttpServletRequest)request;
        if(httpreq.getMethod().equals("POST")) {
            request.setCharacterEncoding(encoding);
        } else {
            request = new Request(httpreq);
        }

    // Pass control on to the next filter
        chain.doFilter(request, response);

    }


    /**
     * Place this filter into service.
     *
     * @param filterConfig The filter configuration object
     */
    public void init(FilterConfig filterConfig) throws ServletException {

    this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
 

    }

}

 

2.web.xml 中增加过滤器配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <filter>
        <filter-name>encodingfilter</filter-name>
        <filter-class>com.filter.SetCharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encodingfilter</filter-name>
        <url-pattern>/jsp/encoding/*</url-pattern>
    </filter-mapping>

  <servlet>
    <description>changecode</description>
    <display-name>changecode</display-name>
    <servlet-name>CodeServlet</servlet-name>
    <servlet-class>com.filter.CodeServlet</servlet-class>
  </servlet>
<servlet-mapping>
    <servlet-name>CodeServlet</servlet-name>
    <url-pattern>/servlet/CodeServlet</url-pattern>
  </servlet-mapping>
</web-app>

 

3.测试页面
(1) test.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>My JSP 'test.jsp' starting page</title>
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
  </head>
  <body>
   <form action="action.jsp">
   GET 方式: <input type=text name="name" value="GET 中文">
   <input type=submit>
   </form>
   <form action="action.jsp" method="POST">
   POST 方式: <input type=text name="name" value="POST 中文">
   <input type=submit>
   </form>
  
   <form action="/Test_2/servlet/CodeServlet">
   GET 方式: <input type=text name="name" value="GET 中文">
   <input type=submit>
   </form>
   <form action="/Test_2/servlet/CodeServlet" method="POST">
   POST 方式: <input type=text name="name" value="POST 中文">
   <input type=submit>
   </form>
  </body>
</html>

 

(2)action.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>My JSP 'action.jsp' starting page</title>
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->
  </head>
   参数: <%=request.getParameter("name") %> <br>
  </body>
</html>

 

(3)CodeServlet.java

package com.filter.codetest;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class CodeServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String name = request.getParameter("name");
        System.out.println("get方式:"+name);
    }

    /**
     * The doPost method of the servlet. <br>
     *
     * This method is called when a form has its tag value method equals to post.
     *
     * @param request the request send by the client to the server
     * @param response the response send by the server to the client
     * @throws ServletException if an error occurred
     * @throws IOException if an error occurred
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String name = request.getParameter("name");
        System.out.println("post方式:"+name);
       
    }

}