1.案例中shrio 逻辑认证会频繁的查询数据库,消耗性能

2.改造一下,把之前学习的缓存中间件拿来用

<!--shiro整合redis缓存,和之前的缓存不同-->
<dependency><groupId>org.crazycake</groupId><artifactId>shiro-redis</artifactId><version>2.4.2.1-RELEASE</version>
</dependency>

这种整合方式没有搞懂 会爆错
具体原因是springboot2.X默认是lettuce客户端
而报错是jedis出来XXX问题,不知道怎么解决
百度了很多都是没用的,所以懒得看了

---

导依赖 commons-pool2 spring-boot-starter-data-redis spring-boot-starter-cache

<!--spring2.0集成redis所需common-pool2-->
<dependency><groupId>org.apache.commons</groupId><artifactId>commons-pool2</artifactId><version>2.4.2</version>
</dependency>
<!-- redis依赖，2.0以上使用这个依赖 -->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<!-- 缓存依赖 -->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-cache</artifactId>
</dependency>

配置文件

#redis
#第几个数据库，由于redis中数据库不止一个
spring.redis.database=2 
# 也可指定为127.0.0.1
spring.redis.host=127.0.0.1
# 默认端口
spring.redis.port=6379 
spring.redis.password=
#默认为空
# springboot2.x以上如此配置，由于2.x的客户端是lettuce
# 单位要带上
spring.redis.lettuce.pool.max-active=8
spring.redis.lettuce.pool.min-idle=1
spring.redis.lettuce.pool.max-idle=8
spring.redis.lettuce.pool.max-wait=10000ms
spring.redis.lettuce.shutdown-timeout=100ms

redis缓存的一些配置

>@Slf4j
@Configuration
@EnableCaching
public class RedisCache extends CachingConfigurerSupport {// 自定义key生成器@Beanpublic KeyGenerator keyGenerator() {return (o, method, params) -> {StringBuilder sb = new StringBuilder ( );sb.append (o.getClass ( ).getName ( )); // 类目sb.append (method.getName ( )); // 方法名for (Object param : params) {sb.append (param.toString ( )); // 参数名}return sb.toString ( );};}// 配置缓存管理器@Beanpublic RedisCacheManager cacheManager(RedisConnectionFactory connectionFactory) {RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig ( ).entryTtl (Duration.ofSeconds (60 * 60 * 24 * 3)) // 缓存*秒失效// 设置key的序列化方式.serializeKeysWith (RedisSerializationContext.SerializationPair.fromSerializer (keySerializer ( )))// 设置value的序列化方式.serializeValuesWith (RedisSerializationContext.SerializationPair.fromSerializer (valueSerializer ( )))// 不缓存null值.disableCachingNullValues ( );RedisCacheManager redisCacheManager = RedisCacheManager.builder (connectionFactory).cacheDefaults (config).transactionAware ( ).build ( );log.info ("自定义RedisCacheManager加载完成");return redisCacheManager;}// key键序列化方式private RedisSerializer<String> keySerializer() {return new StringRedisSerializer ( );}// value值序列化方式private GenericJackson2JsonRedisSerializer valueSerializer() {return new GenericJackson2JsonRedisSerializer ( );}
}

开启缓存 使用注解@EnableCaching

>@EnableCaching
@SpringBootApplication
public class ShiroApplication {public static void main(String[] args) {SpringApplication.run (ShiroApplication.class, args);}}

缓存注解,在业务层调用

@Cacheable在方法上 注意key如果定义了没有的键或值会报500,默认是参数作为simplekey
权限和角色一般都不会变 假如变更了 使用@CacheEvict移除一个或者多个缓存 详情百度

@Service
@Transactional(rollbackFor = Exception.class)
public class UserServiceImpl implements UserService {@AutowiredUserDao userDao;@Override@Cacheable(cacheNames = "users",key ="#name")public User getPwdByName(String name) {System.out.println(name+":数据库查询用户中.....");return userDao.getPwdByName (name);}@Override@Cacheable(cacheNames = "roles",key = "#name")public List<String> listRoles(String name) {System.out.println(name+":数据库查询角色中.....");return userDao.listRoles (name);}@Override@Cacheable(cacheNames = "Permissions",key = "#name")public List<String> listPermissions(String name) {System.out.println(name+":数据库查询用户权限中");return userDao.listPermissions (name);}

测试:
正确输入账号密码都可以使用 但是出现一个Bug 输入错误的登陆会跳出error500 显然之前设置的出错跳转回登陆页失效了
原因是你输入了错误的信息数据库查询不到内容 key为用户名 value为null 缓存策略是value为空不缓存
IllegalArgumentException: Cache ‘users’ does not allow ‘null’ values. Avoid storing null via ‘@Cacheable(unless="#result == null")’ or configure RedisCache to allow ‘null’ via RedisCacheConfiguration.

所以爆了500
解决:
方案1:

@Controller public class LoginController {//表单提交,处理后返回首页@PostMapping("/tologin")String tologin(String name, String password, Model model) {//处理逻辑/**使用Shiro编写认证操作*///1.获取SubjectSubject subject = SecurityUtils.getSubject ( );//2.封装用户数据UsernamePasswordToken token = new UsernamePasswordToken (name, password);//执行登陆方法try {subject.login (token);//登陆信息会交给Realm去执行认证逻辑,比如去数据库对比用户,密码//然后会设置角色,权限} catch (UnknownAccountException e) {model.addAttribute ("msg", "用户名不存在");return "/login";} catch (IncorrectCredentialsException e) {model.addAttribute ("msg", "密码错误");return "/login";}catch (Exception e){//redis 数据库没查到值 model.addAttribute ("msg", "用户名不存在");return "/login";}//这里的请求不能返回"/index"这是返回index.html了 没有经过mvc拦截到// 必须使用"redirect:/index" 或者"forward:/index"//catch块可以跳转是因为我的页面就叫login.html 请求也是/loginreturn "redirect:/index";}

方案2:
设置缓存条件:unless="#result == null" 缓存到redis 除非结果是空

@Override
@Cacheable(cacheNames = "users",key ="#name",unless="#result == null")
public User getPwdByName(String name) {System.out.println(name+":数据库查询用户中.....");return userDao.getPwdByName (name);
}

shrio整合结束,如有错误多多指正~