struts2和servlet同时用（访问servlet时被struts2过滤器拦截问题的解决）

在同一个项目中间，如果既用到servlet有用了struts2的框架，运行项目时可能无法正常使用servlet，原因是在配置struts2的核心控制器时<url-pattern>/*</url-pattern>所致，需要定义一个过滤器，将servlet过滤，使struts2的核心控制器对servlet不起作用。注意：在xml文件中定义的servlet过滤器要写在struts2核心控制器前面，否则还是不能使用。举例来说，定义的过滤器文件是ReDispatcherFilter.java，只需按照该文件中注释内容做以下配置，即可。 

package filters;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
public class ReDispatcherFilter implements Filter {
public void destroy() {
   // TODO Auto-generated method stub
}
public void doFilter(ServletRequest req, ServletResponse resp,
    FilterChain chain) throws IOException, ServletException 
{
  
   HttpServletRequest request = (HttpServletRequest)req;
   String target = request.getRequestURI();
   target = target.lastIndexOf("?")>0   
      ?target.substring(target.lastIndexOf("/")+1,target.lastIndexOf("?")-target.lastIndexOf("/"))
      :target.substring(target.lastIndexOf("/")+1);
  
   System.out.println(target);
   if(this.includes.contains(target))
   {
    RequestDispatcher rdsp = request.getRequestDispatcher(target);
   
    System.out.println("go..............."+rdsp);
    rdsp.forward(req, resp);
   }
   else
    chain.doFilter(req, resp);
}
private ArrayList<String> includes = new ArrayList<String>();

public void init(FilterConfig config) throws ServletException {
  
   this.includes.addAll( Arrays.asList(config.getInitParameter("includeServlets").split(",")));
}
}

/*该类是定义了一个过滤器，当既用到struts2有用到servlet时，
* 必须用该过滤器对所有的servlet做一次过滤，否则servlet将无法正常运行。
* 同时在web.xml中，在定义struts的核心控制器前面添加该过滤器，添加代码如下：
*/ 

<filter>
   <filter-name>redisp</filter-name>
   <filter-class>filters.ReDispatcherFilter（该过滤器的类名）</filter-class>
   <init-param>
    <param-name>includeServlets</param-name>
    <param-value>所有配置的servlet名字</param-value>
   </init-param>
 </filter>
 <filter-mapping>
   <filter-name>redisp</filter-name>
   <url-pattern>/*</url-pattern>
 </filter-mapping>