Shiro —— 从一个简单的例子开始
一、Shiro是用来做权限的。
二、权限
1.基本概念：
（1）安全实体：要保护的数据。
（2）权限：是否有能力去操作（查看、修改、删除 ）保护的数据。
2、权限的两个特性
（1）权限的继承性：A 包含 B，B无权限，但A有权限，此时B 的权限即为 A 的权限。如大厦里有公共厕所，进出大厦需要门禁，所以公共厕所的权限就是大厦的门禁权限。
（2）最近路劲匹配：如大厦某层有卫生间，要想到此卫生间需要有该层电梯权限，此时该卫生间的权限为该层电梯的权限，而不是大厦的门禁权限。
3.几个关键词
（1）认证：验证用户身份，即验证登录的用户名密码是否正确，用户是否被锁死。
（2）授权：决定是否有权限访问受保护的资源。
（3）加密：保护或隐藏受保护的资源。
（4）会话管理
（5）单点登录（SSO）
三、Shiro
1.核心组件
（1）Subject：当前用户。
（2）Shiro SecurityManager：Shiro 大管家。
（3）Realm：用于访问数据库。
2.Shiro SecurityManager
Shiro 的大管家管理着 Shiro 下的认证、授权、会话管理、缓存管理、以及 Realm 访问数据库，贯穿于始终的是加密。
3.用户、角色、权限
（1）概念：
- 用户：通俗来讲，指的就是要登录的用户名密码。
- 角色：权限的集合。
- 权限：是否有能力去做某件事。
（2）关系
- 权限作用于角色，角色是权限的一个集合
- 角色作用于用户，用户是什么角色。
（3）维系关系
- 用户——角色：用户角色中间表。
- 角色——权限：角色权限中间表。
（4）以上所有的这些都归 Shiro 大管家来管理。
四、一个简单的官方的例子
1.需要导入的 jar 包。
2.官方demo。
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ import org.apache.shiro.SecurityUtils; import org.apache.shiro.authc.*; import org.apache.shiro.config.IniSecurityManagerFactory; import org.apache.shiro.mgt.SecurityManager; import org.apache.shiro.session.Session; import org.apache.shiro.subject.Subject; import org.apache.shiro.util.Factory; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Simple Quickstart application showing how to use Shiro's API. * * @since 0.9 RC2 */ public class Quickstart { private static final transient Logger log = LoggerFactory.getLogger(Quickstart.class); public static void main(String[] args) { // The easiest way to create a Shiro SecurityManager with configured // realms, users, roles and permissions is to use the simple INI config. // We'll do that by using a factory that can ingest a .ini file and // return a SecurityManager instance: // Use the shiro.ini file at the root of the classpath // (file: and url: prefixes load from files and urls respectively): Factory<SecurityManager> factory = new IniSecurityManagerFactory("classpath:shiro.ini"); SecurityManager securityManager = factory.getInstance(); // for this simple example quickstart, make the SecurityManager // accessible as a JVM singleton. Most applications wouldn't do this // and instead rely on their container configuration or web.xml for // webapps. That is outside the scope of this simple quickstart, so // we'll just do the bare minimum so you can continue to get a feel // for things. SecurityUtils.setSecurityManager(securityManager); // Now that a simple Shiro environment is set up, let's see what you can do: // get the currently executing user: Subject currentUser = SecurityUtils.getSubject(); // Do some stuff with a Session (no need for a web or EJB container!!!) Session session = currentUser.getSession(); session.setAttribute("someKey", "aValue"); String value = (String) session.getAttribute("someKey"); if (value.equals("aValue")) { log.info("-->Retrieved the correct value! [" + value + "]"); } // let's login the current user so we can check against roles and permissions: if (!currentUser.isAuthenticated()) { UsernamePasswordToken token = new UsernamePasswordToken("lonestarr", "vespa"); token.setRememberMe(true); try { currentUser.login(token); } catch (UnknownAccountException uae) { log.info("-->There is no user with username of " + token.getPrincipal()); } catch (IncorrectCredentialsException ice) { log.info("-->Password for account " + token.getPrincipal() + " was incorrect!"); } catch (LockedAccountException lae) { log.info("The account for username " + token.getPrincipal() + " is locked. " + "Please contact your administrator to unlock it."); } // ... catch more exceptions here (maybe custom ones specific to your application? catch (AuthenticationException ae) { //unexpected condition? error? } } //say who they are: //print their identifying principal (in this case, a username): log.info("-->User [" + currentUser.getPrincipal() + "] logged in successfully."); //test a role: if (currentUser.hasRole("schwartz")) { log.info("-->May the Schwartz be with you!"); } else { log.info("Hello, mere mortal."); } //test a typed permission (not instance-level) if (currentUser.isPermitted("lightsaber:weild")) { log.info("-->You may use a lightsaber ring. Use it wisely."); } else { log.info("Sorry, lightsaber rings are for schwartz masters only."); } //a (very powerful) Instance Level permission: if (currentUser.isPermitted("winnebago:drive:eagle5")) { log.info("-->You are permitted to 'drive' the winnebago with license plate (id) 'eagle5'. " + "Here are the keys - have fun!"); } else { log.info("Sorry, you aren't allowed to drive the 'eagle5' winnebago!"); } //all done - log out! currentUser.logout(); System.exit(0); } }
说明：获取 SecurityManager ，认证，认证失败的几种情况，成功登陆后是否拥有某个角色，某个角色是否有某个权限。
[users] root = secret, admin guest = guest, guest presidentskroob = 12345, president darkhelmet = ludicrousspeed, darklord, schwartz lonestarr = vespa, goodguy, schwartz [roles] admin = * schwartz = lightsaber:* goodguy = winnebago:drive:eagle5
说明：Shiro.ini 文件，用来维系用户——角色——权限之间的关系。
3.ini 文件说明
[users]：用户名=密码，角色1，角色2
[roles]：角色=权限1，权限2
权限：
（1）用简单的字符串来表示一个权限。如：user
（2）多层次管理：如：user:query,user:edit,user:query,edit。第一部分为操作的领域，第二部分为执行的操作。可以使用通配符：user:*,*:query
（3）实例级权限：域：操作：实例
如：user:edit:manager 只能对 user 中的 manager 进行 edit。
通配符：user:edit:*、user:*:*、user:*:manager
等价：user:edit==user:edit:*、user == user:*:* 只能从字符串结尾处省略。
（4）可对比官方例子学习。
五、总结：
介绍了权限的基础，介绍了 Shiro 的 HelloWorld，要明白其中重要的部分，如：认证、授权，以及Shiro 是如何来做这两件事情的。介绍官方demo 的 ini 配置方式，只是想更加深刻的去理解
Shiro 的管理器，认证，授权，角色，权限等等这些概念。
