Spring Cache

Spring Cache常用注解

在示例启动类中开启缓存注解功能

@Slf4j
@SpringBootApplication
@EnableCaching
public class CacheDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(CacheDemoApplication.class,args);
        log.info("项目启动成功...");
    }
}

示例控制层UserController.java

@RestController
@RequestMapping("/user")
@Slf4j
public class UserController {

    @Autowired
    private CacheManager cacheManager;

    @Autowired
    private UserService userService;

    /**
     * CachePut：将方法返回值放入缓存
     * value：缓存的名称，每个缓存名称下面可以有多个key
     * key：缓存的key
     */
    @CachePut(value = "userCache",key = "#user.id")
    @PostMapping
    public User save(User user){
        userService.save(user);
        return user;
    }

    /**
     * CacheEvict：清理指定缓存
     * value：缓存的名称，每个缓存名称下面可以有多个key
     * key：缓存的key
     */
    @CacheEvict(value = "userCache",key = "#p0")
    //@CacheEvict(value = "userCache",key = "#root.args[0]")
    //@CacheEvict(value = "userCache",key = "#id")
    @DeleteMapping("/{id}")
    public void delete(@PathVariable Long id){
        userService.removeById(id);
    }

    //@CacheEvict(value = "userCache",key = "#p0.id")
    //@CacheEvict(value = "userCache",key = "#user.id")
    //@CacheEvict(value = "userCache",key = "#root.args[0].id")
    @CacheEvict(value = "userCache",key = "#result.id")
    @PutMapping
    public User update(User user){
        userService.updateById(user);
        return user;
    }

    /**
     * Cacheable：在方法执行前spring先查看缓存中是否有数据，如果有数据，则直接返回缓存数据；若没有数据，调用方法并将方法返回值放到缓存中
     * value：缓存的名称，每个缓存名称下面可以有多个key
     * key：缓存的key
     * condition：条件，满足条件时才缓存数据
     * unless：满足条件则不缓存
     */
    @Cacheable(value = "userCache",key = "#id",unless = "#result == null")
    @GetMapping("/{id}")
    public User getById(@PathVariable Long id){
        User user = userService.getById(id);
        return user;
    }

    @Cacheable(value = "userCache",key = "#user.id + '_' + #user.name")
    @GetMapping("/list")
    public List<User> list(User user){
        LambdaQueryWrapper<User> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(user.getId() != null,User::getId,user.getId());
        queryWrapper.eq(user.getName() != null,User::getName,user.getName());
        List<User> list = userService.list(queryWrapper);
        return list;
    }
}

Spring Cache使用方式

导入maven坐标

        <!-- Spring整合Redis -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

        <!-- 引入缓存 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-cache</artifactId>
        </dependency>

配置application.yml

spring:
  cache:
    redis:
      time-to-live: 1800000

值得注意的是，对于需要加入缓存的数据，是需要实现序列化Serializable的，否则会缓存失败，例如：自定义的返回结果类型R，就需要public class R<T> implements Serializable才能成功缓存