使用Servlet Filter消除struts乱码

先创建一个Java类，继承自 javax.servlet.Filter ：

package com.test.util;  
 
import javax.servlet.Filter;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.FilterChain;
import java.io.IOException;
 
public class SetCharacterEncodingFilter implements Filter {
 
protected FilterConfig filterConfig;
protected String encodingName;
protected boolean enable;
 
public SetCharacterEncodingFilter() {
this.encodingName = "UTF-8";
this.enable = false;
}
 
public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
loadConfigParams();
}
 
private void loadConfigParams() {
this.encodingName = this.filterConfig.getInitParameter("encoding");
String strIgnoreFlag = this.filterConfig.getInitParameter("enable");
if (strIgnoreFlag.equalsIgnoreCase("true")) {
this.enable = true;
} else {
this.enable = false;
}
}
 
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
if (this.enable) {
request.setCharacterEncoding(this.encodingName);
response.setCharacterEncoding(this.encodingName);
}
chain.doFilter(request, response);
}
 
public void destroy() {
}
}

然后在web.xml中加入Filter的描述和参数配置：

 <filter>  
  <filter-name>SetCharacterEncoding</filter-name>   
  <filter-class>com.test.util.SetCharacterEncodingFilter</filter-class>  
  <init-param>   
   <param-name>encoding</param-name>   
   <param-value>UTF-8</param-value>  
  </init-param>  
  <init-param>  
   <param-name>enable</param-name>  
   <param-value>true</param-value>  
  </init-param>  
  </filter>  
  <filter-mapping>  
   <filter-name>SetCharacterEncoding</filter-name>  
   <servlet-name>action</servlet-name>  
  </filter-mapping>