转 Tomcat 5/6 GBK 编码下完美解决中文表单问题的过滤器

http://www.blogjava.net/beansoft/archive/2007/10/09/151368.html

常见的 Tomcat 5 表单编码提交后乱码的解决方案有很多, 有改 Tomcat Connector 属性的, 有加过滤器的. 但是 Tomcat 自带的那个过滤器只解决了 POST 方式的乱码却不能处理 GET 方式的乱码.  在这里那我就给出一个不需要修改任何 Tomcat 配置文件的完美解决中文问题的过滤器的代码:

首先是我们的测试页面:

GET 方式:
POST 方式:

index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>


"-//W3C//DTD HTML 4.01 Transitional//EN">

  
   
    

  
  
  
   "action.jsp">
   GET 方式: "name" value="GET 中文">
   
   
   
      "action.jsp" method="POST">
   POST 方式: "name" value="POST 中文">
   
   
  

和普通的表单没有任何区别.

然后就是表单提交页面 action.jsp:

<%@ page language="java" pageEncoding="GBK"%>


   参数: <%=request.getParameter("name") %>

 

接着是过滤器的配置文件 web.xml (用 2.5 版本也可以):

 

xml 代码

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>TomcatFormFilter<!---->filter-name>
    <filter-class>filters.TomcatFormFilter<!---->filter-class>
    <!---->filter>

    <filter-mapping>
    <filter-name>TomcatFormFilter<!---->filter-name>
    <url-pattern>*.jsp<!---->url-pattern>
    <!---->filter-mapping>

  <welcome-file-list>
    <welcome-file>index.jsp<!---->welcome-file>
  <!---->welcome-file-list>
<!---->web-app>

最后最关键的就是我们的过滤器代码了, 对 GET 方式使用请求包装器, 而 POST 方式则用 setCharacterEncoding():

java 代码

ackage filters;

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

public class TomcatFormFilter implements Filter {
    /**
      * Request.java
      * 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.
      */

    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 GBK.
         */
        public String toChi(String input) {
            try {
              byte[] bytes = input.getBytes("ISO8859-1");
              return new String(bytes, "GBK");
            }
            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 destroy() {

    }

    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpreq = (HttpServletRequest)request;
        if(httpreq.getMethod().equals("POST")) {
            request.setCharacterEncoding("GBK");
        } else {
            request = new Request(httpreq);
        }

        chain.doFilter(request, response);
    }

    public void init(FilterConfig filterConfig) throws ServletException {
    }

}