# 具体遇到的问题
5-2中在写代码时发现tomcat启动时就运行过滤器中的代码，不是访问对应url才执行吗？
# 报错信息的截图
​# 相关课程内容截图

# 尝试过的解决思路和结果

# 粘贴全部相关代码，切记添加代码注释（请勿截图）

package com.imooc.management.filter;

import java.io.IOException;

import javax.servlet.Filter;

import javax.servlet.FilterChain;

import javax.servlet.FilterConfig;

import javax.servlet.ServletContext;

import javax.servlet.ServletException;

import javax.servlet.ServletRequest;

import javax.servlet.ServletResponse;

import javax.servlet.annotation.WebFilter;

import javax.servlet.http.HttpServletResponse;

/**

 * Servlet Filter implementation class AuthFilter

 */

@WebFilter(filterName="AuthFilter",urlPatterns="/*")

public class AuthFilter implements Filter {

    /**

     * Default constructor. 

     */

    public AuthFilter() {

        // TODO Auto-generated constructor stub

    }

/**

* @see Filter#destroy()

*/

public void destroy() {

// TODO Auto-generated method stub

}

/**

* @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)

*/

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

//1,判断用户是否登陆,2,判断用户名密码是否匹配

ServletContext context = request.getServletContext();

HttpServletResponse res = (HttpServletResponse)response;

int flag = (int)context.getAttribute("flag");

System.out.println(flag);

System.out.println("过滤器在运行");

chain.doFilter(request, response);

// if(flag == 1) {

// chain.doFilter(request, response);

// }else if(flag == 0) {

// res.sendRedirect("/login.html");

// chain.doFilter(request, response);

// }

}

/**

* @see Filter#init(FilterConfig)

*/

public void init(FilterConfig fConfig) throws ServletException {

// TODO Auto-generated method stub

}

}