SpringBoot Cache操作

在上一节JPA操作基础上修改

Cache缓存策略：使更少的操作数据库，更快的返回数据

1、引入cache依赖

1<dependency>
2            <groupId>org.springframework.boot</groupId>
3            <artifactId>spring-boot-starter-cache</artifactId>
4</dependency>

2.主要是修改UserSerViceImpl服务层实现类

1@Service
2@Transactional  //事务
3public class UserServiceImpl implements UserService {
4
5    @Autowired
6    private UserRepository userRepository;
7
8    @Override
9    @Cacheable(value = "user", key = "#id")
10    public User findUserById(Integer id) {
11        System.out.println("查询用户查询数据库");
12        return userRepository.getOne(id);
13    }
14
15    @Override
16    @Cacheable(value = "userListPage" , key = "#pageable") //key值可视化,每页的key值是不同的
17    public Page<User> findUserListPage(Pageable pageable) {
18        System.out.println("分页查询数据库");
19        return userRepository.findAll(pageable);
20    }
21    @Override
22    //@CacheEvict(value = "users",key = "#id")  //清空缓存中以users和key值缓存策略缓存的对象
23    @CacheEvict(value = "userListPage",allEntries = true)  //清空所有缓存中以users缓存策略缓存的对象
24    public void saveUser(User user) {
25        userRepository.save(user);
26    }
27
28    /*
29        注解Caching可以混合几个注解
30     */
31    @Override
32    @Caching(evict = {@CacheEvict(cacheNames = "user",key = "#user.id"),
33            @CacheEvict(cacheNames = "user2" ,key = "user2.id")})
34    public void updateUser(User user) {
35
36    }
37
38}

3.测试TsetController类

1@Controller
2public class TestController {
3
4    @Autowired
5    private UserService userService;
6 
7    @RequestMapping("/getUserById")
8    public @ResponseBody User getUserById(){
9        System.out.println(userService.findUserById(1527));
10        System.out.println(userService.findUserById(1527));
11        System.out.println(userService.findUserById(1528));
12        return userService.findUserById(1527);
13    }
14  
15}

4.对启动类添加缓存注解

1@SpringBootApplication
2@EnableCaching  //对缓存做配置
3public class DemoApplication {
4
5    public static void main(String[] args) {
6        SpringApplication.run(DemoApplication.class, args);
7    }
8
9}

5.进行测试：

运行结果：

第二次查询数据库是因为id不同没有这个缓存，会去查询数据库的