Shiro框架

1、Shiro简介

1.1、什么是Shiro?

  • Apache Shiro是一个Java的安全(权限)框架。
  • Shiro可以非常容易的开发出足够好的应用,其不仅可以用在JavaSE环境,也可以用在JavaEE环境。
  • Shiro可以完成,认证,授权,加密,会话管理,Web集成,缓存等。
  • 下载地址:http://shiro.apache.org/

SpringBoot整合Shiro框架 - 图1

1.2、有哪些功能?

SpringBoot整合Shiro框架 - 图2

  • Authentication:身份认证、登录,验证用户是不是拥有相应的身份;

  • Authorization:授权,即权限验证,验证某个已认证的用户是否拥有某个权限,即判断用户能否进行什么操作,如:验证某个用户是否拥有某个角色,或者细粒度的验证某个用户对某个资源是否具有某个权限!

  • Session Manager:会话管理,即用户登录后就是第一次会话,在没有退出之前,它的所有信息都在会话中;
    会话可以是普通的JavaSE环境,也可以是Web环境;

  • Cryptography:加密,保护数据的安全性,如密码加密存储到数据库中,而不是明文存储;

  • Web Support:Web支持,可以非常容易的集成到Web环境

  • Caching:缓存,比如用户登录后,其用户信息,拥有的角色、权限不必每次去查,这样可以提高效率

  • Concurrency:Shiro支持多线程应用的并发验证,即,如在一个线程中开启另一个线程,能把权限自动的传播过去

  • Testing:提供测试支持;

  • RunAs:允许一个用户假装为另一个用户(如果他们允许)的身份进行访问;

  • Remember Me:记住我,这个是非常常见的功能,即一次登录后,下次再来的话不用登录了

1.3、Shiro架构(外部)

  1. 从外部来看Shiro,即从应用程序角度来观察如何使用shiro完成工作

SpringBoot整合Shiro框架 - 图3

  • subject:应用代码直接交互的对象是Subject,也就是说Shiro的对外API核心就是Subject,Subject代表了当前的用户,这个用户不一定是一个具体的人,与当前应用交互的任何东西都是Subject,如网络爬虫,机器人等,与Subject的所有交互都会委托给SecurityManager;Subject其实是一个门面,SecurityManageer才是实际的执行者

  • SecurityManager:安全管理器,即所有与安全有关的操作都会与SercurityManager交互,并且它管理着所有的Subject,可以看出它是Shiro的核心,它负责与Shiro的其他组件进行交互,它相当于SpringMVC的DispatcherServlet的角色

  • Realm:Shiro从Realm获取安全数据(如用户,角色,权限),就是说SecurityManager要验证用户身份,那么它需要从Realm获取相应的用户进行比较,来确定用户的身份是否合法;也需要从Realm得到用户相应的角色、权限,进行验证用户的操作是否能够进行,可以把Realm看成DataSource;

1.4、Shiro架构(内部)

SpringBoot整合Shiro框架 - 图4

  • Subject:任何可以与应用交互的用户;
  • Security Manager:相当于SpringMVC中的DispatcherServlet;是Shiro的心脏,所有具体的交互都通过
    Security Manager进行控制,它管理者所有的Subject,且负责进行认证,授权,会话,及缓存的管理。
  • Authenticator:负责Subject认证,是一个扩展点,可以自定义实现;可以使用认证策略(AuthenticationStrategy),即什么情况下算用户认证通过了;
  • Authorizer:授权器,即访问控制器,用来决定主体是否有权限进行相应的操作;即控制着用户能访问应用中的那些功能;
  • Realm:可以有一个或者多个的realm,可以认为是安全实体数据源,即用于获取安全实体的,可以用JDBC实现,也可以是内存实现等等,由用户提供;所以一般在应用中都需要实现自己的realm
  • SessionManager:管理Session生命周期的组件,而Shiro并不仅仅可以用在Web环境,也可以用在普通的JavaSE环境中
  • CacheManager:缓存控制器,来管理如用户,角色,权限等缓存的;因为这些数据基本上很少改变,放到缓存中后可以提高访问的性能;
  • Cryptography:密码模块,Shiro提高了一些常见的加密组件用于密码加密,解密等

2、HelloWorld

2.2、快速实战

查看官网文档:http://shiro.apache.org/tutorial.html

官方的quickstart:https://github.com/apache/shiro/tree/master/samples/quickstart/

  1. 创建一个maven父工程,用于学习Shiro,删掉不必要的东西

  2. 创建一个普通的Maven子工程:shiro-01-helloworld

  3. 根据官方文档,我们来导入Shiro的依赖

    1. <dependencies>
    2. <dependency>
    3. <groupId>org.apache.shiro</groupId>
    4. <artifactId>shiro-core</artifactId>
    5. <version>1.4.1</version>
    6. </dependency>
    7. <dependency>
    8. <groupId>org.slf4j</groupId>
    9. <artifactId>slf4j-simple</artifactId>
    10. <version>1.7.21</version>
    11. </dependency>
    12. <dependency>
    13. <groupId>org.slf4j</groupId>
    14. <artifactId>jcl-over-slf4j</artifactId>
    15. <version>1.7.21</version>
    16. </dependency>
    17. <dependency>
    18. <groupId>log4j</groupId>
    19. <artifactId>log4j</artifactId>
    20. <version>1.2.17</version>
    21. </dependency>
    22. </dependencies>
  1. 配置文件
    shiro.ini ```ini [users] root = secret, admin guest = guest, guest presidentskroob = 12345, president darkhelmet = ludicrousspeed, darklord, schwartz lonestarr = vespa, goodguy, schwartz

——————————————————————————————————————-

Roles with assigned permissions

roleName = perm1, perm2, …, permN

——————————————————————————————————————-

[roles] admin = schwartz = lightsaber: goodguy = winnebago:drive:eagle5

  1. <br />log4j.properties
  2. ```properties
  3. log4j.rootLogger=INFO, stdout
  4. log4j.appender.stdout=org.apache.log4j.ConsoleAppender
  5. log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
  6. log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m %n
  7. # General Apache libraries
  8. log4j.logger.org.apache=WARN
  9. # Spring
  10. log4j.logger.org.springframework=WARN
  11. # Default Shiro logging
  12. log4j.logger.org.apache.shiro=INFO
  13. # Disable verbose logging
  14. log4j.logger.org.apache.shiro.util.ThreadContext=WARN
  15. log4j.logger.org.apache.shiro.cache.ehcache.EhCache=WARN
  1. Quickstart ```java 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 {

      //使用log来输出 private static final transient Logger log = LoggerFactory.getLogger(Quickstart.class);

  1. public static void main(String[] args) {
  2. // The easiest way to create a Shiro SecurityManager with configured
  3. // realms, users, roles and permissions is to use the simple INI config.
  4. // We'll do that by using a factory that can ingest a .ini file and
  5. // return a SecurityManager instance:
  6. //创建带有配置的Shiro SecurityManager的最简单方法
  7. //领域,用户,角色和权限是使用简单的INI配置。
  8. //我们将使用可提取.ini文件的工厂来完成此操作,
  9. //返回一个SecurityManager实例:
  10. // Use the shiro.ini file at the root of the classpath
  11. // (file: and url: prefixes load from files and urls respectively):
  12. //在类路径的根目录下使用shiro.ini文件
  13. //(file:和url:前缀分别从文件和url加载):
  14. Factory<SecurityManager> factory = new IniSecurityManagerFactory("classpath:shiro.ini");
  15. SecurityManager securityManager = factory.getInstance();
  16. // for this simple example quickstart, make the SecurityManager
  17. // accessible as a JVM singleton. Most applications wouldn't do this
  18. // and instead rely on their container configuration or web.xml for
  19. // webapps. That is outside the scope of this simple quickstart, so
  20. // we'll just do the bare minimum so you can continue to get a feel
  21. // for things.
  22. //对于这个简单的示例快速入门,请使SecurityManager
  23. //作为JVM 单例 访问。大多数应用程序都不会这样做
  24. //,而是依靠其容器配置或web.xml进行
  25. // webapps。这超出了此简单快速入门的范围,因此
  26. //我们只做最低限度的工作,所以您可以继续感受一下
  27. // 为了这些事。
  28. SecurityUtils.setSecurityManager(securityManager);
  29. // Now that a simple Shiro environment is set up, let's see what you can do:
  30. //获取当前正在用户对象Subject:
  31. Subject currentUser = SecurityUtils.getSubject();
  32. //通过当前用户获取Session
  33. Session session = currentUser.getSession();
  34. session.setAttribute("someKey", "aValue");
  35. String value = (String) session.getAttribute("someKey");
  36. if (value.equals("aValue")) {
  37. log.info("Subject===>session [" + value + "]");
  38. }
  39. // 判断当前用户是否被认证
  40. if (!currentUser.isAuthenticated()) {
  41. // token 令牌 没有获取,随机
  42. UsernamePasswordToken token = new UsernamePasswordToken("lonestarr", "vespa");
  43. // 设置记住我
  44. token.setRememberMe(true);
  45. try {
  46. // 执行了登陆操作
  47. currentUser.login(token);
  48. } catch (UnknownAccountException uae) {
  49. // 未知账号
  50. log.info("There is no user with username of " + token.getPrincipal());
  51. } catch (IncorrectCredentialsException ice) {
  52. // 密码错误
  53. log.info("Password for account " + token.getPrincipal() + " was incorrect!");
  54. } catch (LockedAccountException lae) {
  55. // 账号锁定
  56. log.info("The account for username " + token.getPrincipal() + " is locked. " +
  57. "Please contact your administrator to unlock it.");
  58. }
  59. // ... catch more exceptions here (maybe custom ones specific to your application?
  60. catch (AuthenticationException ae) {
  61. // 认证异常
  62. //unexpected condition? error?
  63. }
  64. }
  65. //say who they are:
  66. //print their identifying principal (in this case, a username):
  67. // 获取当前用户认证码,可以存储信息
  68. log.info("User [" + currentUser.getPrincipal() + "] logged in successfully.");
  69. //test a role:
  70. // 测试角色
  71. if (currentUser.hasRole("schwartz")) {
  72. log.info("May the Schwartz be with you!");
  73. } else {
  74. log.info("Hello, mere mortal.");
  75. }
  76. //test a typed permission (not instance-level)
  77. // 测试输入的权限 粗粒度权限
  78. if (currentUser.isPermitted("lightsaber:wield")) {
  79. log.info("You may use a lightsaber ring. Use it wisely.");
  80. } else {
  81. log.info("Sorry, lightsaber rings are for schwartz masters only.");
  82. }
  83. //a (very powerful) Instance Level permission:
  84. // 细粒度权限
  85. if (currentUser.isPermitted("winnebago:drive:eagle5")) {
  86. log.info("You are permitted to 'drive' the winnebago with license plate (id) 'eagle5'. " +
  87. "Here are the keys - have fun!");
  88. } else {
  89. log.info("Sorry, you aren't allowed to drive the 'eagle5' winnebago!");
  90. }
  91. // 注销
  92. //all done - log out!
  93. currentUser.logout();
  94. System.exit(0);
  95. }

}

  1. ```java
  2. //获取当前正在用户对象Subject:
  3. Subject currentUser = SecurityUtils.getSubject();
  4. //通过当前用户获取Session
  5. Session session = currentUser.getSession();
  6. //用户认证
  7. currentUser.isAuthenticated();
  8. //获取当前用户认证码,(可以存储信息)
  9. currentUser.getPrincipal();
  10. //用户——>角色
  11. currentUser.hasRole("schwartz");
  12. //角色权限
  13. currentUser.isPermitted("lightsaber:wield");
  14. //注销
  15. currentUser.logout();

3、SpringBoot整合Shiro

3.1、环境搭建

1、导入依赖

  1. <!--shiro整合spring-->
  2. <dependency>
  3. <groupId>org.apache.shiro</groupId>
  4. <artifactId>shiro-spring</artifactId>
  5. <version>1.4.1</version>
  6. </dependency>
  7. <!--thymeleaf模板-->
  8. <dependency>
  9. <groupId>org.thymeleaf</groupId>
  10. <artifactId>thymeleaf-spring5</artifactId>
  11. </dependency>
  12. <dependency>
  13. <groupId>org.thymeleaf.extras</groupId>
  14. <artifactId>thymeleaf-extras-java8time</artifactId>
  15. </dependency>

2、编写Config配置类

  1. //自定义Realm
  2. public class UserRealm extends AuthorizingRealm {
  3. //授权
  4. @Override
  5. protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principalCollection) {
  6. System.out.println("==执行了授权==");
  7. return null;
  8. }
  9. //认证
  10. @Override
  11. protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authenticationToken) throws AuthenticationException {
  12. System.out.println("==执行了认证==");
  13. return null;
  14. }
  15. }
  1. @Configuration
  2. public class ShiroConfig {
  3. //ShiroFilterFactoryBean:3
  4. @Bean
  5. public ShiroFilterFactoryBean getShiroFilterFactoryBean(@Qualifier("securityManager") DefaultWebSecurityManager defaultWebSecurityManager) {
  6. ShiroFilterFactoryBean bean = new ShiroFilterFactoryBean();
  7. //设置安全管理器
  8. bean.setSecurityManager(defaultWebSecurityManager);
  9. return bean;
  10. }
  11. //DefaultWebSecurityManager:2
  12. @Bean(name = "securityManager")
  13. public DefaultWebSecurityManager getDefaultWebSecurityManager(@Qualifier("userRealm") UserRealm userRealm) {
  14. DefaultWebSecurityManager securityManager = new DefaultWebSecurityManager();
  15. //关联Realm
  16. securityManager.setRealm(userRealm());
  17. return securityManager;
  18. }
  19. //创建realm对象, 需要自定义类:1
  20. @Bean
  21. public UserRealm userRealm() {
  22. return new UserRealm();
  23. }
  24. }
  1. 页面跳转
  1. @Controller
  2. public class MyController {
  3. @RequestMapping({"/","index"})
  4. public String index(Model model) {
  5. model.addAttribute("msg","hello,Shiro");
  6. return "index";
  7. }
  8. @RequestMapping("/user/add")
  9. public String add() {
  10. return "user/add";
  11. }
  12. @RequestMapping("/user/update")
  13. public String update() {
  14. return "user/update";
  15. }
  16. }

3.2、登录拦截

增加配置

  1. //添加shiro的内置过滤器
  2. /*
  3. anon:无需认证就可以访问
  4. authc:必须认证了才能让问
  5. user:必须拥有记住我功能才能用
  6. perms:拥有对某个资源的权限才能访问
  7. role:拥有某个角色权限才能访问
  8. */
  9. /*
  10. filterMap.put("/user/add","authc");
  11. filterMap.put("/user/update","authc");
  12. */
  13. //登录拦截
  14. Map<String, String> filterMap = new LinkedHashMap<>();
  15. filterMap.put("/user/*","authc");
  16. bean.setFilterChainDefinitionMap(filterMap);
  17. //设置登录请求
  18. bean.setLoginUrl("/toLogin");

跳转

  1. @RequestMapping("/toLogin")
  2. public String toLogin() {
  3. return "login";
  4. }

3.3、用户认证

增加用户判断

  1. @RequestMapping("/login")
  2. public String login(String username, String password, Model model) {
  3. //获取当前用户
  4. Subject subject = SecurityUtils.getSubject();
  5. //封装用户登录数据
  6. UsernamePasswordToken token = new UsernamePasswordToken(username, password);
  7. try {
  8. //执行登录方法
  9. subject.login(token);
  10. return "index";
  11. } catch (UnknownAccountException e) {
  12. //用户名不存在
  13. model.addAttribute("msg","用户名错误");
  14. return "login";
  15. } catch (IncorrectCredentialsException e) {
  16. //密码不正确
  17. model.addAttribute("msg","密码错误");
  18. return "login";
  19. }
  20. }

给UserRealm增加新的配置

  1. //认证
  2. @Override
  3. protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
  4. System.out.println("==执行了认证==");
  5. //用户名,密码 数据中取
  6. String name="root";
  7. String password="root";
  8. UsernamePasswordToken userToken = (UsernamePasswordToken) token;
  9. if (!userToken.getUsername().equals(name)) {
  10. //抛出异常 UnknownAccountException
  11. return null;
  12. }
  13. //密码认证Shiro做
  14. return new SimpleAuthenticationInfo("",password,"");
  15. }

3.4、整合Mybatis

导入依赖

  1. <dependency>
  2. <groupId>org.projectlombok</groupId>
  3. <artifactId>lombok</artifactId>
  4. <version>1.16.10</version>
  5. </dependency>
  6. <!--
  7. Subject用户
  8. SecurityManager 管理所有用户
  9. Realm连接数据
  10. -->
  11. <!--连接mysql-->
  12. <dependency>
  13. <groupId>mysql</groupId>
  14. <artifactId>mysql-connector-java</artifactId>
  15. </dependency>
  16. <!--druid-->
  17. <dependency>
  18. <groupId>com.alibaba</groupId>
  19. <artifactId>druid</artifactId>
  20. <version>1.1.12</version>
  21. </dependency>
  22. <!--mybatis-->
  23. <dependency>
  24. <groupId>org.mybatis.spring.boot</groupId>
  25. <artifactId>mybatis-spring-boot-starter</artifactId>
  26. <version>2.1.0</version>
  27. </dependency>
  28. <!--log4j-->
  29. <dependency>
  30. <groupId>log4j</groupId>
  31. <artifactId>log4j</artifactId>
  32. <version>1.2.17</version>
  33. </dependency>

配置application.yml 数据库和mybatis

  1. spring:
  2. datasource:
  3. username: root
  4. password: 123456
  5. #?serverTimezone=UTC解决时区的报错
  6. url: jdbc:mysql://localhost:3306/mybatisK?useUnicode=true&characterEncoding=utf-8
  7. driver-class-name: com.mysql.cj.jdbc.Driver
  8. type: com.alibaba.druid.pool.DruidDataSource
  9. #Spring Boot 默认是不注入这些属性值的,需要自己绑定
  10. #druid 数据源专有配置
  11. initialSize: 5
  12. minIdle: 5
  13. maxActive: 20
  14. maxWait: 60000
  15. timeBetweenEvictionRunsMillis: 60000
  16. minEvictableIdleTimeMillis: 300000
  17. validationQuery: SELECT 1 FROM DUAL
  18. testWhileIdle: true
  19. testOnBorrow: false
  20. testOnReturn: false
  21. poolPreparedStatements: true
  22. #配置监控统计拦截的filters,stat:监控统计、log4j:日志记录、wall:防御sql注入
  23. #如果允许时报错 java.lang.ClassNotFoundException: org.apache.log4j.Priority
  24. #则导入 log4j 依赖即可,Maven 地址:https://mvnrepository.com/artifact/log4j/log4j
  25. filters: stat,wall,log4j
  26. maxPoolPreparedStatementPerConnectionSize: 20
  27. useGlobalDataSourceStat: true
  28. connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
  29. # 整合 mybatis
  30. mybatis:
  31. type-aliases-package: cn.dafran.pojo
  32. mapper-locations: classpath:mapper/*.xml
  33. # #缓存
  34. # thymeleaf:
  35. # cache: false
  36. #
  37. # #我们的配置文件的真实位置
  38. # messages:
  39. # basename: i18n.login
  40. #
  41. # mvc:
  42. # #时间日期格式化
  43. # date-format: yyyy-MM-dd
  44. # #是否开启默认图标
  45. # favicon:
  46. # enabled: false
  47. #
  48. #

修改UserRealm配置

  1. @Autowired
  2. UserServiceImpl userService;
  3. //认证
  4. @Override
  5. protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
  6. System.out.println("==执行了认证==");
  7. UsernamePasswordToken userToken = (UsernamePasswordToken) token;
  8. //连接真实数据库
  9. User user = userService.queryUserByName(userToken.getUsername());
  10. if (user == null) {
  11. return null;
  12. }
  13. //密码认证Shiro做
  14. return new SimpleAuthenticationInfo("",user.getPwd(),"");
  15. }

编写pojo、dao、service

3.5、请求授权实现

增加权限配置

ShiroConfig

  1. public ShiroFilterFactoryBean getShiroFilterFactoryBean(@Qualifier("securityManager") DefaultWebSecurityManager defaultWebSecurityManager) {
  2. //授权,正常的情况下,没有授权会跳转到未授权页面
  3. filterMap.put("/user/add","perms[user:add]");
  4. filterMap.put("/user/update","perms[user:update]");
  5. filterMap.put("/user/*","authc");
  6. bean.setFilterChainDefinitionMap(filterMap);
  7. //设置登录请求
  8. bean.setLoginUrl("/toLogin");
  9. //设置未授权页面
  10. bean.setUnauthorizedUrl("/noauth");
  11. }

Controller增加

  1. @RequestMapping("/noauth")
  2. @ResponseBody
  3. public String unauthorized() {
  4. return "未经授权无法访问";
  5. }

修改Realm

  1. public class UserRealm extends AuthorizingRealm {
  2. @Autowired
  3. UserServiceImpl userService;
  4. //授权
  5. @Override
  6. protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principalCollection) {
  7. System.out.println("==执行了授权==");
  8. //SimpleAuthenticationInfo
  9. SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();
  10. //增加权限
  11. /*info.addStringPermission("user:add");*/
  12. Subject subject = SecurityUtils.getSubject();
  13. User currentUser = (User) subject.getPrincipal(); //拿到user对象
  14. //设置当前用户对象
  15. info.addStringPermission(currentUser.getPerms());
  16. return info;
  17. }
  18. //认证
  19. @Override
  20. protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
  21. System.out.println("==执行了认证==");
  22. UsernamePasswordToken userToken = (UsernamePasswordToken) token;
  23. //连接真实数据库
  24. User user = userService.queryUserByName(userToken.getUsername());
  25. if (user == null) {
  26. return null;
  27. }
  28. return new SimpleAuthenticationInfo(user,user.getPwd(),"");
  29. }
  30. }

3.6、整合Thymelafe

导入依赖

  1. <!--shiro整合thymeleaf-->
  2. <dependency>
  3. <groupId>com.github.theborakompanioni</groupId>
  4. <artifactId>thymeleaf-extras-shiro</artifactId>
  5. <version>2.0.0</version>
  6. </dependency>

ShiroConfig 增加配置

  1. //整合ShiroDialect:用来整合 shiro thymeleaf
  2. @Bean
  3. public ShiroDialect getShiroDialect() {
  4. return new ShiroDialect();
  5. }

验证session

  1. //认证
  2. @Override
  3. protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) throws AuthenticationException {
  4. System.out.println("==执行了认证==");
  5. UsernamePasswordToken userToken = (UsernamePasswordToken) token;
  6. //连接真实数据库
  7. User user = userService.queryUserByName(userToken.getUsername());
  8. if (user == null) {
  9. return null;
  10. }
  11. /*//加密方式
  12. String hashAlgorithmName = "MD5";
  13. ByteSource credential = ByteSource.Util.bytes(user.getPwd());
  14. String realpwd=user.getPwd();
  15. //密码认证Shiro做*/
  16. /*判断是否有用户*/
  17. Subject currentSubject = SecurityUtils.getSubject();
  18. Session session = currentSubject.getSession();
  19. session.setAttribute("loginUser",user);
  20. return new SimpleAuthenticationInfo(user,user.getPwd(),"");
  21. }

修改页面

  1. <div shiro:hasPermission="user:add">
  2. <a th:href="@{/user/add}">add</a>|
  3. </div>
  4. <div shiro:hasPermission="user:update">
  5. <a th:href="@{/user/update}">update</a>
  6. </div>
  1. <div th:if="${session.loginUser==null}">
  2. <a th:href="@{/toLogin}">登录</a>
  3. </div>