脚本之家 服务器常用软件
快捷导航
您的位置：首页 → 软件编程 → java → javaweb设计中filter粗粒度权限控制

javaweb设计中filter粗粒度权限控制代码示例

 更新时间：2017年10月14日 14:10:42   作者：bluzelee2011  
这篇文章主要介绍了javaweb设计中filter粗粒度权限控制代码示例，小编觉得还是挺不错的，需要的朋友可以参考。

1 说明

我们给出三个页面：index.jsp、user.jsp、admin.jsp。

index.jsp：谁都可以访问，没有限制；

user.jsp：只有登录用户才能访问；

admin.jsp：只有管理员才能访问。

2 分析

设计User类：username、password、grade，其中grade表示用户等级，1表示普通用户，2表示管理员用户。

当用户登录成功后，把user保存到session中。

创建LoginFilter，它有两种过滤方式：

如果访问的是user.jsp，查看session中是否存在user；
如果访问的是admin.jsp，查看session中是否存在user，并且user的grade等于2。

3 代码

<?xml version="1.0" encoding="UTF-8"?> 
<web-app version="2.5" 
 xmlns="http://java.sun.com/xml/ns/javaee" 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
 http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> 
<servlet> 
 <servlet-name>LoginServlet</servlet-name> 
 <servlet-class>com.cug.web.servlet.LoginServlet</servlet-class> 
</servlet> 
<servlet-mapping> 
 <servlet-name>LoginServlet</servlet-name> 
 <url-pattern>/LoginServlet</url-pattern> 
</servlet-mapping> 
<welcome-file-list> 
 <welcome-file>index.jsp</welcome-file> 
</welcome-file-list> 
<filter> 
 <filter-name>UserFilter</filter-name> 
 <filter-class>com.cug.filter.UserFilter</filter-class> 
</filter> 
<filter-mapping> 
 <filter-name>UserFilter</filter-name> 
 <url-pattern>/user/*</url-pattern> 
</filter-mapping> 
<filter> 
 <filter-name>AdminFilter</filter-name> 
 <filter-class>com.cug.filter.AdminFilter</filter-class> 
</filter> 
<filter-mapping> 
 <filter-name>AdminFilter</filter-name> 
 <url-pattern>/admin/*</url-pattern> 
</filter-mapping> 
</web-app>

LoginServlet.java

package com.cug.web.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.cug.domain.User;
import com.cug.web.service.UserService;
public class LoginServlet extends HttpServlet{
	@Override 
	 protected void doPost(HttpServletRequest req, HttpServletResponse resp) 
	   throws ServletException, IOException {
		req.setCharacterEncoding("utf-8");
		resp.setContentType("text/html;charset=utf-8");
		String username = req.getParameter("username");
		String password = req.getParameter("password");
		User user = UserService.login(username, password);
		if(user == null){
			req.setAttribute("msg", "用户名或者密码错误");
			req.getRequestDispatcher("/login.jsp").forward(req, resp);
		} else{
			req.getSession().setAttribute("user", user);
			req.getRequestDispatcher("index.jsp").forward(req,resp);
		}
	}
}

UserService

package com.cug.web.service;
import java.util.HashMap;
import java.util.Map;
import com.cug.domain.User;
public class UserService {
	private static Map<String, User> users = new HashMap<String, User>();
	static{
		users.put("zhu", new User("zhu", "123", 2));
		users.put("xiao", new User("xiao", "123", 1));
	}
	public static User login(String username, String password){
		User user = users.get(username);
		if(user == null) 
		   return null;
		if(!user.getPassword().equals(password)) 
		   return null;
		return user;
	}
}

AdminFilter

package com.cug.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 com.cug.domain.User;
public class AdminFilter implements Filter{
	@Override 
	 public void destroy() {
	}
	@Override 
	 public void doFilter(ServletRequest req, ServletResponse resp, 
	   FilterChain chain) throws IOException, ServletException {
		req.setCharacterEncoding("utf-8");
		resp.setContentType("text/html;charset=utf-8");
		HttpServletRequest request = (HttpServletRequest)req;
		User user = (User)request.getSession().getAttribute("user");
		if(user == null){
			resp.getWriter().print("用户还没有登陆");
			request.getRequestDispatcher("/login.jsp").forward(req, resp);
		}
		if(user.getGrade() < 2){
			resp.getWriter().print("您的等级不够");
			return;
		}
		chain.doFilter(req, resp);
	}
	@Override 
	 public void init(FilterConfig arg0) throws ServletException {
	}
}

UserFilter

package com.cug.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 com.cug.domain.User;
public class UserFilter implements Filter{
	@Override 
	 public void destroy() {
	}
	@Override 
	 public void doFilter(ServletRequest request, ServletResponse response, 
	   FilterChain chain) throws IOException, ServletException {
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
		HttpServletRequest httpReq = (HttpServletRequest)request;
		User user = (User)httpReq.getSession().getAttribute("user");
		if(user == null){
			request.getRequestDispatcher("/login.jsp").forward(request, response);
		}
		chain.doFilter(request, response);
	}
	@Override 
	 public void init(FilterConfig filterConfig) throws ServletException {
	}
}

User

package com.cug.domain;
public class User {
	private String username;
	private String password;
	private int grade;
	public User() {
		super();
	}
	public User(String username, String password, int grade) {
		super();
		this.username = username;
		this.password = password;
		this.grade = grade;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public int getGrade() {
		return grade;
	}
	public void setGrade(int grade) {
		this.grade = grade;
	}
	@Override 
	 public String toString() {
		return "User [username=" + username + ", password=" + password 
		    + ", grade=" + grade + "]";
	}
}

html

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> 
<% 
String path = request.getContextPath(); 
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 
%> 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 
<html> 
 <head> 
 <base href="<%=basePath%>" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 <title>My JSP 'admin.jsp' starting page</title> 
 <meta http-equiv="pragma" content="no-cache"> 
 <meta http-equiv="cache-control" content="no-cache"> 
 <meta http-equiv="expires" content="0">  
 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> 
 <meta http-equiv="description" content="This is my page"> 
 <!-- 
 <link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 --> 
 </head> 
 <body> 
 <h1>admin.jsp</h1> 
 <h3>${user.username }</h3> 
 <a href="<c:url value='/index.jsp'/>" rel="external nofollow" rel="external nofollow" rel="external nofollow" >首页</a><br/> 
 <a href="<c:url value='/user/user.jsp'/>" rel="external nofollow" rel="external nofollow" rel="external nofollow" >用户页</a><br/> 
 <a href="<c:url value='/admin/admin.jsp'/>" rel="external nofollow" rel="external nofollow" rel="external nofollow" >系统管理员</a><br/> 
 </body> 
</html> 

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
<% 
String path = request.getContextPath(); 
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 
%> 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 
<html> 
 <head> 
 <base href="<%=basePath%>" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 <title>My JSP 'user.jsp' starting page</title> 
 <meta http-equiv="pragma" content="no-cache"> 
 <meta http-equiv="cache-control" content="no-cache"> 
 <meta http-equiv="expires" content="0">  
 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> 
 <meta http-equiv="description" content="This is my page"> 
 <!-- 
 <link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 --> 
 </head> 
 <body> 
 <h1>user.jsp</h1> 
 <h3>${user.username }</h3> 
 <a href="<c:url value='/index.jsp'/>" rel="external nofollow" rel="external nofollow" rel="external nofollow" >首页</a><br> 
 <a href="<c:url value='/user/user.jsp'/>" rel="external nofollow" rel="external nofollow" rel="external nofollow" >用户登陆界面</a><br> 
 <a href="<c:url value='/admin/admin.jsp'/>" rel="external nofollow" rel="external nofollow" rel="external nofollow" >管理员登陆界面</a><br> 
 </body> 
</html>

用户登录

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> 
<% 
String path = request.getContextPath(); 
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 
%> 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 
<html> 
 <head> 
 <base href="<%=basePath%>" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 <title>My JSP 'login.jsp' starting page</title> 
 <meta http-equiv="pragma" content="no-cache"> 
 <meta http-equiv="cache-control" content="no-cache"> 
 <meta http-equiv="expires" content="0">  
 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> 
 <meta http-equiv="description" content="This is my page"> 
 <!-- 
 <link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 --> 
 </head> 
 <body> 
 ${msg } 
 <form action="<c:url value='/LoginServlet'/>" method="post"> 
  用户名：<input type="text" name="username"/><br/> 
  密码：<input type="password" name="password"/><br/> 
  <input type="submit" value="登陆"/> 
 </form> 
 </body> 
</html> 

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%> 
<% 
String path = request.getContextPath(); 
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 
%> 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 
<html> 
 <head> 
 <base href="<%=basePath%>" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 <title>My JSP 'index.jsp' starting page</title> 
 <meta http-equiv="pragma" content="no-cache"> 
 <meta http-equiv="cache-control" content="no-cache"> 
 <meta http-equiv="expires" content="0">  
 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> 
 <meta http-equiv="description" content="This is my page"> 
 <!-- 
 <link rel="stylesheet" type="text/css" href="styles.css" rel="external nofollow" rel="external nofollow" rel="external nofollow" rel="external nofollow" > 
 --> 
 </head> 
 <body> 
 <h1>index.jsp</h1> 
 <h3>${user.username }</h3> 
 <a href="<c:url value='/index.jsp'/>" rel="external nofollow" rel="external nofollow" rel="external nofollow" >首页</a><br> 
 <a href="<c:url value='/user/user.jsp'/>" rel="external nofollow" rel="external nofollow" rel="external nofollow" >用户登陆界面</a><br> 
 <a href="<c:url value='/admin/admin.jsp'/>" rel="external nofollow" rel="external nofollow" rel="external nofollow" >管理员登陆界面</a><br> 
 </body> 
</html>

总结

以上就是本文关于javaweb设计中filter粗粒度权限控制代码示例的全部内容，感兴趣的朋友可以继续参阅：JavaWeb项目中dll文件动态加载方法解析（详细步骤）、Javaweb使用cors完成跨域ajax数据交互、Javaweb项目session超时解决方案等。

希望对大家有所帮助，如有不足之处，欢迎留言指正。感谢大家对本站的支持！

您可能感兴趣的文章:

相关文章

  • Java单例模式的讲解

    Java单例模式的讲解

    今天小编就为大家分享一篇关于Java单例模式的讲解，小编觉得内容挺不错的，现在分享给大家，具有很好的参考价值，需要的朋友一起跟随小编来看看吧
    2019-01-01
  • 使用Zxing实现二维码生成器内嵌图片

    使用Zxing实现二维码生成器内嵌图片

    二维码在现实中的应用已经很广泛了，本文介绍了使用Zxing实现二维码生成器内嵌图片，有需要的可以了解一下。
    2016-10-10
  • Java对比两个实体的差异分析

    Java对比两个实体的差异分析

    这篇文章主要介绍了Java对比两个实体的差异分析，具有很好的参考价值，希望对大家有所帮助。如有错误或未考虑完全的地方，望不吝赐教
    2021-12-12
  • Java 最重要布局管理器GridBagLayout的使用方法

    Java 最重要布局管理器GridBagLayout的使用方法

    GridBagLayout是java里面最重要的布局管理器之一,可以做出很复杂的布局，可以说GridBagLayout是必须要学好的的,需要的朋友可以了解下
    2012-12-12
  • springboot之如何获取项目目录路径

    springboot之如何获取项目目录路径

    这篇文章主要介绍了springboot之如何获取项目目录路径问题，具有很好的参考价值，希望对大家有所帮助。如有错误或未考虑完全的地方，望不吝赐教
    2023-05-05
  • springboot jpa 实现返回结果自定义查询

    springboot jpa 实现返回结果自定义查询

    这篇文章主要介绍了springboot jpa 实现返回结果自定义查询方式，具有很好的参考价值，希望对大家有所帮助。如有错误或未考虑完全的地方，望不吝赐教
    2022-02-02
  • Spring配置shiro时自定义Realm中属性无法使用注解注入的解决办法

    Spring配置shiro时自定义Realm中属性无法使用注解注入的解决办法

    今天小编就为大家分享一篇关于Spring配置shiro时自定义Realm中属性无法使用注解注入的解决办法，小编觉得内容挺不错的，现在分享给大家，具有很好的参考价值，需要的朋友一起跟随小编来看看吧
    2019-03-03
  • 关于Springboot日期时间格式化处理方式总结

    关于Springboot日期时间格式化处理方式总结

    这篇文章主要介绍了关于Springboot日期时间格式化处理方式总结,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值，需要的朋友们下面随着小编来一起学习学习吧
    2020-03-03
  • Java基础教程之封装与接口

    Java基础教程之封装与接口

    这篇文章主要介绍了Java基础教程之封装与接口,本文用浅显易懂的语言讲解了Java中的封装与接口,很形象的说明了这两个面向对象术语,需要的朋友可以参考下
    2014-08-08
  • 详解Java中如何使用日志库在代码中添加日志

    详解Java中如何使用日志库在代码中添加日志

    这篇文章主要为大家介绍了Java中如何使用日志库在代码中添加日志详解，有需要的朋友可以借鉴参考下，希望能够有所帮助，祝大家多多进步，早日升职加薪
    2023-07-07

最新评论