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[Java教程]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.// 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, adminguest = guest, guestpresidentskroob = 12345, presidentdarkhelmet = ludicrousspeed, darklord, schwartzlonestarr = 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。