SpringBoot使用Redis實現自動緩存更新刪除

本篇主要講述如何使用基本的註解 @Cacheable @CachePut @CacheEvict 操作緩存

1.我們導入Redis的依賴


 <dependency>
 <groupid>org.springframework.boot/<groupid>
 <artifactid>spring-boot-starter-data-redis/<artifactid>
 <version>1.5.10.RELEASE/<version>
 /<dependency>
 <dependency>
 <groupid>org.springframework.boot/<groupid>
 <artifactid>spring-boot-starter-cache/<artifactid>
 /<dependency>

 <dependency>
 <groupid>org.springframework.boot/<groupid>
 <artifactid>spring-boot-configuration-processor/<artifactid>
 <optional>true/<optional>
 /<dependency>

2.編寫配置類

@ConfigurationProperties(prefix = "spring.cache.redis")
@Configuration
public class RedisConfig {
 private Duration timeToLive = Duration.ZERO;
 public void setTimeToLive(Duration timeToLive) {
 this.timeToLive = timeToLive;
 }
 @Bean
 /**
 * 該bean只針對cache存入到數據亂碼問題
 */
 public RedisCacheManager cacheManager(RedisConnectionFactory factory) { 

 RedisSerializer<string> redisSerializer = new StringRedisSerializer();
 Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
 //解決查詢緩存轉換異常的問題
 ObjectMapper om = new ObjectMapper();
 om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
 om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
 jackson2JsonRedisSerializer.setObjectMapper(om);
 // 配置序列化（解決亂碼的問題）
 RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
 .entryTtl(timeToLive)
 .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer))
 .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer))
 .disableCachingNullValues();
 RedisCacheManager cacheManager = RedisCacheManager.builder(factory)
 .cacheDefaults(config)
 .build();
 return cacheManager;
 }
}
/<string>

3.配置文件

#要連接的數據是哪個
spring.redis.database=1
#數據連接地址
spring.redis.host=localhost
#端口號
spring.redis.port=6379
#連接超時時間
spring.redis.timeout=1s
#最大連接數
spring.redis.jedis.pool.max-active=20
#最大空閒連接
spring.redis.jedis.pool.max-idle=20
#最小空閒連接
spring.redis.jedis.pool.min-idle=10
#最大等待阻塞等待時間
spring.redis.jedis.pool.max-wait=-1ms
#在寫入Redis時是否要使用key前綴 

spring.cache.redis.use-key-prefix=true
#key前綴
spring.cache.redis.key-prefix=dev
#是否允許有null值
spring.cache.redis.cache-null-values=false
#設置緩存存在時間，只針對cacheable存入數據有用
spring.cache.redis.time-to-live=120s

4.現在我們的環境準備好了，開始編寫代碼

這裡是pojo

@Table(name = "user1")
public class User implements Serializable {
 @Id
 private Integer id;
 private String name;
 private String pwd;
 public Integer getId() {
 return id;
 }
 public void setId(Integer id) {
 this.id = id;
 }
 public String getName() {
 return name;
 }
 public void setName(String name) {
 this.name = name;
 }
 public String getPwd() {
 return pwd;
 }
 public void setPwd(String pwd) {
 this.pwd = pwd;
 }
 @Override
 public String toString() {
 return "User{" +
 "id=" + id +
 ", name='" + name + '\\'' +
 ", pwd='" + pwd + '\\'' +
 '}'; 

 }
}

這裡是dao類

@org.apache.ibatis.annotations.Mapper
public interface UserMapper extends Mapper<user> {
}
/<user>

這裡是在service類上使用註解

@CacheConfig(cacheNames = "user")//注意,用於同一配置給其它註解配置名稱
public class UserServiceImpl implements UserService {
 @Autowired
 private UserMapper userMapper;
 @Override
 @Cacheable(key="#p0")//該註解用於向緩存中存入數據
 public User findUser(Integer id) {
 System.out.println("查詢數據了"+id);
 User user = userMapper.selectByPrimaryKey(id);
 return user;
 }
 @Override
 @CachePut(key="#p0.id")//該註解用於更新緩存中的註解
 public User updateUser(User user) {
 userMapper.updateByPrimaryKeySelective(user);
 return user;
 }
 @Override
 @CacheEvict(key="#p0")//該註解用於刪除緩存
 public void deleteUser(Integer id) {
 userMapper.deleteByPrimaryKey(id);
 }
 @Override
 public List<user> findUsers() {
 return userMapper.selectAll();
 }
}
/<user>

注意，這裡需要說明一下，#p0代表第一個參數，返回值默認是方法的返回值,@Cacheable之類的註解必須要有value值，這裡我在類上加@CacheConfig註解，使下面的註解有了同一個value值

這裡是controller裡面的代碼

@RestController
@RequestMapping("/user")
public class UserController {
 @Resource
 private UserService userService;
 @GetMapping
 public ResponseEntity<list>> findUsers(){
 try {
 List<user> users = userService.findUsers();
 
 return new ResponseEntity<>(users,HttpStatus.OK);
 } catch (Exception e) {
 e.printStackTrace();
 return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
 }
 }
 @GetMapping("/{id}")
 public ResponseEntity<user> findUser(@PathVariable("id")Integer id){
 try {
 User user = userService.findUser(id);
 return new ResponseEntity<>(user, HttpStatus.OK);
 } catch (Exception e) {
 e.printStackTrace();
 return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
 }
 }
 @PutMapping
 public ResponseEntity<string> updateUser(@RequestBody User user){
 try {
 userService.updateUser(user);
 return new ResponseEntity<>("修改成功",HttpStatus.OK);
 } catch (Exception e) {
 e.printStackTrace();
 return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
 }
 }
 @DeleteMapping("/{id}")
 public ResponseEntity<void> deleteUser(@PathVariable("id")Integer id){ 

 try {
 userService.deleteUser(id);
 return new ResponseEntity<>(HttpStatus.OK);
 } catch (Exception e) {
 e.printStackTrace();
 return new ResponseEntity<>(HttpStatus.INTERNAL_SERVER_ERROR);
 }
 }
}
/<void>/<string>/<user>/<user>/<list>