在struts2中使用filter来配置servlet处理业务

在一个struts2项目中，如果同时用到了servlet和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的核心控制器时如下配置所致
<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>
此时要想请求不经过该FilterDispatcher过滤器而直接响应servlet，可以通过自定义一个过滤器，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
<filter>

<filter-name>redisp</filter-name>

<filter-class>filters.ReDispatcherFilter</filter-class>

<init-param>

<param-name>includeServlets</param-name>

<param-value>attachmentUpload.do,aa.do</param-value>

</init-param>

</filter>

<filter-mapping>

<filter-name>redisp</filter-name>

<url-pattern>/*</url-pattern>

</filter-mapping>

<servlet>

<servlet-name>attachmentUpload</servlet-name>

<servlet-class>com.yan.AttachmentUploadServlet</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>attachmentUpload</servlet-name>

<url-pattern>/attachmentUpload.do</url-pattern>

</servlet-mapping>
在filters包下定义ReDispatcherFilter类，如下：
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

{

System.out.println(" filter beginning...........");

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);

for(int i=0;i<this.includes.size();i++)

System.out.println(this.includes.get(i));

if(this.includes.contains(target))

{

System.out.println("includes.contains(target) is true");

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(",")));
}
}