struts action接到form汉字乱码解决（过滤器）

首先在项目中建一个包com.common.filter。
然后再将tomcat的webapps/examples/WEB-INF/classes/filters中的SetCharacterEncodingFilter.java拷到项目新建的com.common.filter包中。
然后在web.xml中添加：
      注意添加的红色过滤器部分，位置固定在最前面，否则action得到的汉字就变为???了

<?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">

    <!-- jsp过滤器 -->
    <filter>
          <filter-name>Set   Character   Encoding</filter-name>
           //这里根据文件实际位置来写
          <filter-class>com.common.filter.SetCharacterEncodingFilter</filter-class>
          <init-param>
              <param-name>encoding</param-name>
              <param-value>UTF-8</param-value>
          </init-param>
      </filter>
      <filter-mapping>
          <filter-name>Set   Character   Encoding</filter-name>
          <url-pattern>/*</url-pattern>
      </filter-mapping>
    
    <!-- struts2 配置信息 -->
    <filter>
        <filter-name>struts2</filter-name>
        <filter-class>
            org.apache.struts2.dispatcher.FilterDispatcher
        </filter-class>
    </filter>
    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!-- spring 配置信息 -->
    <listener>
        <listener-class>
            org.springframework.web.context.ContextLoaderListener
        </listener-class>
    </listener>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/classes/applicationContext.xml
        </param-value>
    </context-param>  


    <welcome-file-list>
        <welcome-file>registe/registe.jsp</welcome-file>
    </welcome-file-list>
</web-app>






附带SetCharacterEncodingFilter.java文件内容：

package com.common.filter;  //改为你放置文件的包

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;


public class SetCharacterEncodingFilter implements Filter {

    protected String encoding = null;
    protected FilterConfig filterConfig = null;
    protected boolean ignore = true;

    public void destroy() {

        this.encoding = null;
        this.filterConfig = null;

    }

    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
    throws IOException, ServletException {

        // Conditionally select and set the character encoding to be used
        if (ignore || (request.getCharacterEncoding() == null)) {
            String encoding = selectEncoding(request);
            if (encoding != null)
                request.setCharacterEncoding(encoding);
        }

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

    }


    public void init(FilterConfig filterConfig) throws ServletException {

    this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
        String value = filterConfig.getInitParameter("ignore");
        if (value == null)
            this.ignore = true;
        else if (value.equalsIgnoreCase("true"))
            this.ignore = true;
        else if (value.equalsIgnoreCase("yes"))
            this.ignore = true;
        else
            this.ignore = false;

    }

    protected String selectEncoding(ServletRequest request) {

        return (this.encoding);

    }
}