Java web过滤器验证登录(避免未经登录进入主页)
今天用ssh2写了个简单的系统,发现了一个问题,我这系统必须先登录成功才能进入主页,但我在浏览器里直接输入主页地址,发现也能进入,这个肯定不好,毫无安全性可言,后经查资料发现需要登录过滤器,就试了下,发现果然可以避免未经登录即可进入主页的危险,下面是我整理出的详细步骤:
1.首先写一个权限过滤filter类,实现Filter接口
1 import java.io.IOException;
2
3 import javax.servlet.Filter;
4 import javax.servlet.FilterChain;
5 import javax.servlet.FilterConfig;
6 import javax.servlet.ServletException;
7 import javax.servlet.ServletRequest;
8 import javax.servlet.ServletResponse;
9 import javax.servlet.http.HttpServletRequest;
10 import javax.servlet.http.HttpServletResponse;
11 import javax.servlet.http.HttpSession;
12
13 public class LoginFilter implements Filter {
14
15 @Override
16 public void init(FilterConfig filterConfig) throws ServletException {
17 // TODO Auto-generated method stub
18
19 }
20
21 @Override
22 public void doFilter(ServletRequest request, ServletResponse response,
23 FilterChain chain) throws IOException, ServletException {
24 // 获得在下面代码中要用的request,response,session对象
25 HttpServletRequest servletRequest = (HttpServletRequest) request;
26 HttpServletResponse servletResponse = (HttpServletResponse) response;
27 HttpSession session = servletRequest.getSession();
28
29 // 获得用户请求的URI
30 String path = servletRequest.getRequestURI();
31 //System.out.println(path);
32
33 // 从session里取员工工号信息
34 String empId = (String) session.getAttribute("empId");
35
36 /*创建类Constants.java,里面写的是无需过滤的页面
37 for (int i = 0; i < Constants.NoFilter_Pages.length; i++) {
38
39 if (path.indexOf(Constants.NoFilter_Pages[i]) > -1) {
40 chain.doFilter(servletRequest, servletResponse);
41 return;
42 }
43 }*/
44
45 // 登陆页面无需过滤
46 if(path.indexOf("/login.jsp") > -1) {
47 chain.doFilter(servletRequest, servletResponse);
48 return;
49 }
50
51 // 判断如果没有取到员工信息,就跳转到登陆页面
52 if (empId == null || "".equals(empId)) {
53 // 跳转到登陆页面
54 servletResponse.sendRedirect("/JingXing_OA/login.jsp");
55 } else {
56 // 已经登陆,继续此次请求
57 chain.doFilter(request, response);
58 }
59
60 }
61
62 @Override
63 public void destroy() {
64 // TODO Auto-generated method stub
65
66 }
67
68 }
2.然后在web.xml里配置需要登陆权限验证的JSP文件:
a.如果是某个具体的JSP文件(如a.jsp)需要登陆验证
1 <!-- 配置登陆过滤器 -->
2 <filter>
3 <filter-name>login</filter-name>
4 <filter-class>com.jingxing.oa.filter.LoginFilter</filter-class>
5 </filter>
6
7 <filter-mapping>
8 <filter-name>login</filter-name>
9 <url-pattern>/*</url-pattern>
10 </filter-mapping>
b.如果是某一个目录(如a/目录)整个目录下的文件都需要登陆验证:
1 <!-- 配置登陆过滤器 -->
2 <filter>
3 <filter-name>login</filter-name>
4 <filter-class>com.jingxing.oa.filter.LoginFilter</filter-class>
5 </filter>
6
7 <filter-mapping>
8 <filter-name>login</filter-name>
9 <url-pattern>/a/*</url-pattern>
10 </filter-mapping>
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