添加合法用户验证的过滤器

当非用户访问页面时，需要过滤器判断是否是合法用户：

• 解决方法：新建SessionFilter，用来判断session中是否保存了currentUser
• 如果没有currentUser，表明当前不是一个登录合法的用户，应该跳转到登录页面让其登录

【SessionFilter.java】

package com.javaweb.myssm.filters;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebFilter(urlPatterns = {"*.do","*.html"})
public class sessionFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        HttpSession session = request.getSession();
        Object currUserObj = session.getAttribute("currentUser");
        if (currUserObj == null) {
            response.sendRedirect("page.do?operation=page&page=login");
        } else {
            filterChain.doFilter(request,response);
        }
    }

    @Override
    public void destroy() {

    }
}

添加过滤器后出现的问题：

最终的解决方案，是将合法用户的正常请求设为白名单

【SessionFilter.java】

package com.javaweb.myssm.filters;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

@WebFilter(urlPatterns = {"*.do","*.html"},
         initParams = {
            @WebInitParam(name = "white",
                    value = "/07book/page.do?operation=page&page=user/login,/07book/user.do?null")
         })
public class sessionFilter implements Filter {

    List whiteList = new ArrayList<>();

    @Override
    public void init(FilterConfig config) throws ServletException {
        String white = config.getInitParameter("white");
        String[] whiteArr = white.split(",");
        whiteList = Arrays.asList(whiteArr);
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;

        System.out.println("request.getRequestURI():" + request.getRequestURI());
        System.out.println("request.getQueryString():" + request.getQueryString());

        String uri = request.getRequestURI();
        String queryString = request.getQueryString();
        String str = uri + "?" + queryString;
        if (whiteList.contains(str)) {
            filterChain.doFilter(request,response);
        } else {
            HttpSession session = request.getSession();
            Object currUserObj = session.getAttribute("currentUser");
            if (currUserObj == null) {
                response.sendRedirect("page.do?operation=page&page=user/login");
            } else {
                filterChain.doFilter(request,response);
            }
        }
    }

    @Override
    public void destroy() {

    }
}