关于Struts里提交中文表单到ActionForm后的乱码问题

由于Struts框架直接把表单数据发送给了ActionForm，所以这里面没有对HttpRequestServlet进行SetCharacterEncoding,所以默认是按照ISO-8859-1(参见Tomcat 源代码中的org.apache.catalina.connector.HttpRequestBase中的protected void parseParameters()方法)，

解决的方法，就是在表单提交到ActionForm之前对request进行编码。
第一种方法，就是写一个过滤器，对所有请求进行过滤

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过滤器代码：

package com.first.struts.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;

public class SetCharacterEncodingFilter implements Filter {

private String encoding;
private FilterConfig filterConfig = null;

public void destroy() {
this.encoding = null;
this.filterConfig = null;

}

public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
request.setCharacterEncoding(this.encoding);
chain.doFilter(request, response);
}

public void init(FilterConfig filterConfig) throws ServletException {
this.encoding = filterConfig.getInitParameter("encoding");
}

}

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配置文件web.xml
<filter>
<filter-name>Set Character Encoding</filter-name>
<filter-class>com.first.struts.filters.SetCharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>GBK</param-value>
</init-param>
</filter>

<filter-mapping>
<filter-name>Set Character Encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</filter-mapping>

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第二种方法是替换默认的控制器org.apache.struts.action.ActionServlet

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子类代码：
package jp.co.ricoh.gtis.others.profile.controllers;

import java.io.IOException;

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

import org.apache.struts.action.ActionServlet;

public class SetEncodingActionServlet extends ActionServlet {

protected void process(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
// TODO Auto-generated method stub
String encoding = getInitParameter("encoding");
request.setCharacterEncoding(encoding);
super.process(request, response);
}

}

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配置文件web.xml
<servlet>
<servlet-name>testAction</servlet-name>
<servlet-class>jp.co.ricoh.gtis.others.profile.controllers.SetEncodingActionServlet</servlet-class>
<init-param>
<param-name>config</param-name>
<param-value>/WEB-INF/struts-config.xml</param-value>
</init-param>
<init-param>
<param-name>encoding</param-name>
<param-value>Shift_JIS</param-value>
</init-param>
<load-on-startup>2</load-on-startup>
</servlet>

<servlet-mapping>
<servlet-name>testAction</servlet-name>
<url-pattern>*.testdo</url-pattern>
</servlet-mapping>

此例，凡是通过*.testdo来请求的数据，都会经过参数encoding设定的值来编码。