登录过滤器的问题，输入分类管理和图书管理的地址可以直接访问，新建分量或者图书点提交就返回了登录界面

package com.imooc.filter;

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;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.imooc.user.User;

public class JspFilter implements Filter {

@Override

public void destroy() {

// TODO Auto-generated method stub

}

@Override

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)

throws IOException, ServletException {

HttpServletRequest req=(HttpServletRequest)request;

HttpServletResponse res=(HttpServletResponse)response;

String user=(String)req.getSession().getAttribute("ex");

String uri=req.getRequestURI();

String[] urls= {"/KaptchaServlet","/LoginServlet",".js",".css",".ico",".jpg",".png"};

boolean flag=false;

for(String str:urls) {

if(uri.indexOf(str)!=-1) {

flag=true;

break;

}

}

if(flag||user!=null) {

chain.doFilter(request, response);

return;

}else {

res.sendRedirect(req.getContextPath()+"/login.jsp");

}

}

@Override

public void init(FilterConfig filterConfig) throws ServletException {

// TODO Auto-generated method stub

}

}

<filter>

  <filter-name>JspFilter</filter-name>

  <filter-class>com.imooc.filter.JspFilter</filter-class>

  </filter>

<filter-mapping>

<filter-name>JspFilter</filter-name>

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

</filter-mapping>