struts2过滤器拦截servlet处理问题

问题：
      报表服务器部和客户应用做集成时，客户的应用中通常会用到struts2，并且由于安全上的考虑会加上自带的过滤器，拦截执行的servlet，如下：
 <filter>
  <filter-name>struts2</filter-name>
  <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
 </filter>
 <filter-mapping>
  <filter-name>struts2</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>
这样对导致润乾的reportServlet在访问时会被拦截，打印、导出或做参数表单查询时出现异常。
解决方案：
同样可以定义过滤器，然后在过滤器中增加配置，允许配置的servlet执行。
Java代码：
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() {
  }
 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);
    if (this.includes.contains(target)) {
   RequestDispatcher rdsp = request.getRequestDispatcher(target);
   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(“,”)));

 }

}

将该java程序编译后放到类路径下，并且要在web.xml中增加配置：
<filter>
  <filter-name>redisp</filter-name>
  <filter-class>filters.ReDispatcherFilter</filter-class>
  <init-param>
   <param-name>includeServlets</param-name>
   <param-value>reportServlet </param-value>
  </init-param>
 </filter>
 <filter-mapping>
  <filter-name>redisp</filter-name>
  <url-pattern>/*</url-pattern>
  <dispatcher>REQUEST</dispatcher>
 </filter-mapping>
其中 includeServlets 对应的值为允许执行的servlet，将润乾的reportServlet在这里边配置即可，如果要允许多个servlet，此处用逗号隔开即可