Spring Boot + Redis 实现各种操作，写得太好了吧！

曾经终败给现在 2022-09-11 14:22 186阅读 0赞

来源：blog.csdn.net/qq\_42105629/article/details/102589319

## **一、Jedis,Redisson,Lettuce三者的区别** ##

共同点：都提供了基于Redis操作的Java API，只是封装程度，具体实现稍有不同。

不同点：

**1.1、Jedis**

是Redis的Java实现的客户端。支持基本的数据类型如：String、Hash、List、Set、Sorted Set。

特点：使用阻塞的I/O，方法调用同步，程序流需要等到socket处理完I/O才能执行，不支持异步操作。Jedis客户端实例不是线程安全的，需要通过连接池来使用Jedis。

**1.2、Redisson**

优点点：分布式锁，分布式集合，可通过Redis支持延迟队列。

**1.3、 Lettuce**

用于线程安全同步，异步和响应使用，支持集群，Sentinel，管道和编码器。

基于Netty框架的事件驱动的通信层，其方法调用是异步的。Lettuce的API是线程安全的，所以可以操作单个Lettuce连接来完成各种操作。

## **二、RedisTemplate** ##

### 2.1、使用配置 ###

maven配置引入，（要加上版本号，我这里是因为Parent已声明）

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-redis</artifactId>
    </dependency>

application-dev.yml

spring:
      redis:
        host: 192.168.1.140
        port: 6379
        password:
        database: 15 # 指定redis的分库（共16个0到15）

Spring Boot 基础就不介绍了，推荐下这个实战教程： [https://github.com/javastacks/spring-boot-best-practice][https_github.com_javastacks_spring-boot-best-practice]

### 2.2、使用示例 ###

@Resource
     private StringRedisTemplate stringRedisTemplate;
    
        @Override
        public CustomersEntity findById(Integer id) {
            // 需要缓存
            // 所有涉及的缓存都需要删除，或者更新
            try {
                String toString = stringRedisTemplate.opsForHash().get(REDIS_CUSTOMERS_ONE, id + "").toString();
                if (toString != null) {
                    return JSONUtil.toBean(toString, CustomersEntity.class);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            // 缓存为空的时候，先查,然后缓存redis
            Optional<CustomersEntity> byId = customerRepo.findById(id);
            if (byId.isPresent()) {
                CustomersEntity customersEntity = byId.get();
                try {
                    stringRedisTemplate.opsForHash().put(REDIS_CUSTOMERS_ONE, id + "", JSONUtil.toJsonStr(customersEntity));
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return customersEntity;
            }
            return null;
        }

### 2.3、扩展 ###

##### 2.3.1、spring-boot-starter-data-redis的依赖包 #####

![20210917142249229.png][]

##### 3.3.2、stringRedisTemplate API（部分展示） #####

*  opsForHash --> hash操作
 *  opsForList --> list操作
 *  opsForSet --> set操作
 *  opsForValue --> string操作
 *  opsForZSet --> Zset操作

![20210917142249550.png][]

##### 3.3.3 StringRedisTemplate默认序列化机制 #####

public class StringRedisTemplate extends RedisTemplate<String, String> {
    
         /**
          * Constructs a new <code>StringRedisTemplate</code> instance. {@link #setConnectionFactory(RedisConnectionFactory)}
          * and {@link #afterPropertiesSet()} still need to be called.
          */
         public StringRedisTemplate() {
          RedisSerializer<String> stringSerializer = new StringRedisSerializer();
          setKeySerializer(stringSerializer);
          setValueSerializer(stringSerializer);
          setHashKeySerializer(stringSerializer);
          setHashValueSerializer(stringSerializer);
         }
     }

## **三、RedissonClient 操作示例** ##

### 3.1 基本配置 ###

##### 3.1.1、Maven pom 引入 #####

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-redis</artifactId>
    </dependency>
    <dependency>
        <groupId>org.redisson</groupId>
        <artifactId>redisson</artifactId>
        <version>3.8.2</version>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.redisson</groupId>
        <artifactId>redisson-spring-boot-starter</artifactId>
        <version>LATEST</version>
    </dependency>

##### 3.1.2、添加配置文件Yaml或者json格式 #####

redisson-config.yml

# Redisson 配置
    singleServerConfig:
      address: "redis://192.168.1.140:6379"
      password: null
      clientName: null
      database: 15 #选择使用哪个数据库0~15
      idleConnectionTimeout: 10000
      pingTimeout: 1000
      connectTimeout: 10000
      timeout: 3000
      retryAttempts: 3
      retryInterval: 1500
      reconnectionTimeout: 3000
      failedAttempts: 3
      subscriptionsPerConnection: 5
      subscriptionConnectionMinimumIdleSize: 1
      subscriptionConnectionPoolSize: 50
      connectionMinimumIdleSize: 32
      connectionPoolSize: 64
      dnsMonitoringInterval: 5000
      #dnsMonitoring: false
    
    threads: 0
    nettyThreads: 0
    codec:
      class: "org.redisson.codec.JsonJacksonCodec"
    transportMode: "NIO"

或者，配置 redisson-config.json

{
      "singleServerConfig": {
        "idleConnectionTimeout": 10000,
        "pingTimeout": 1000,
        "connectTimeout": 10000,
        "timeout": 3000,
        "retryAttempts": 3,
        "retryInterval": 1500,
        "reconnectionTimeout": 3000,
        "failedAttempts": 3,
        "password": null,
        "subscriptionsPerConnection": 5,
        "clientName": null,
        "address": "redis://192.168.1.140:6379",
        "subscriptionConnectionMinimumIdleSize": 1,
        "subscriptionConnectionPoolSize": 50,
        "connectionMinimumIdleSize": 10,
        "connectionPoolSize": 64,
        "database": 0,
        "dnsMonitoring": false,
        "dnsMonitoringInterval": 5000
      },
      "threads": 0,
      "nettyThreads": 0,
      "codec": null,
      "useLinuxNativeEpoll": false
    }

##### 3.1.3、读取配置 #####

新建读取配置类

@Configuration
    public class RedissonConfig {
    
        @Bean
        public RedissonClient redisson() throws IOException {
    
            // 两种读取方式，Config.fromYAML 和 Config.fromJSON
    //        Config config = Config.fromJSON(RedissonConfig.class.getClassLoader().getResource("redisson-config.json"));
            Config config = Config.fromYAML(RedissonConfig.class.getClassLoader().getResource("redisson-config.yml"));
            return Redisson.create(config);
        }
    }

或者，在 application.yml中配置如下

spring:
      redis:
        redisson:
          config: classpath:redisson-config.yaml

### 3.2 使用示例 ###

@RestController
    @RequestMapping("/")
    public class TeController {
    
        @Autowired
        private RedissonClient redissonClient;
    
        static long i = 20;
        static long sum = 300;
    
    //    ========================== String =======================
        @GetMapping("/set/{key}")
        public String s1(@PathVariable String key) {
            // 设置字符串
            RBucket<String> keyObj = redissonClient.getBucket(key);
            keyObj.set(key + "1-v1");
            return key;
        }
    
        @GetMapping("/get/{key}")
        public String g1(@PathVariable String key) {
            // 设置字符串
            RBucket<String> keyObj = redissonClient.getBucket(key);
            String s = keyObj.get();
            return s;
        }
    
        //    ========================== hash =======================-=
    
        @GetMapping("/hset/{key}")
        public String h1(@PathVariable String key) {
    
            Ur ur = new Ur();
            ur.setId(MathUtil.randomLong(1,20));
            ur.setName(key);
          // 存放 Hash
            RMap<String, Ur> ss = redissonClient.getMap("UR");
            ss.put(ur.getId().toString(), ur);
            return ur.toString();
        }
    
        @GetMapping("/hget/{id}")
        public String h2(@PathVariable String id) {
            // hash 查询
            RMap<String, Ur> ss = redissonClient.getMap("UR");
            Ur ur = ss.get(id);
            return ur.toString();
        }
    
        // 查询所有的 keys
        @GetMapping("/all")
        public String all(){
            RKeys keys = redissonClient.getKeys();
            Iterable<String> keys1 = keys.getKeys();
            keys1.forEach(System.out::println);
            return keys.toString();
        }
    
        // ================== ==============读写锁测试 =============================
    
        @GetMapping("/rw/set/{key}")
        public void rw_set(){
    //        RedissonLock.
            RBucket<String> ls_count = redissonClient.getBucket("LS_COUNT");
            ls_count.set("300",360000000l, TimeUnit.SECONDS);
        }
    
        // 减法运算
        @GetMapping("/jf")
        public void jf(){
    
            String key = "S_COUNT";
    
    //        RAtomicLong atomicLong = redissonClient.getAtomicLong(key);
    //        atomicLong.set(sum);
    //        long l = atomicLong.decrementAndGet();
    //        System.out.println(l);
    
            RAtomicLong atomicLong = redissonClient.getAtomicLong(key);
            if (!atomicLong.isExists()) {
                atomicLong.set(300l);
            }
    
            while (i == 0) {
                if (atomicLong.get() > 0) {
                    long l = atomicLong.getAndDecrement();
                            try {
                                Thread.sleep(1000l);
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                    i --;
                    System.out.println(Thread.currentThread().getName() + "->" + i + "->" + l);
                }
            }
    
    
        }
    
        @GetMapping("/rw/get")
        public String rw_get(){
    
            String key = "S_COUNT";
            Runnable r = new Runnable() {
                @Override
                public void run() {
                    RAtomicLong atomicLong = redissonClient.getAtomicLong(key);
                    if (!atomicLong.isExists()) {
                        atomicLong.set(300l);
                    }
                    if (atomicLong.get() > 0) {
                        long l = atomicLong.getAndDecrement();
                        i --;
                        System.out.println(Thread.currentThread().getName() + "->" + i + "->" + l);
                    }
                }
            };
    
            while (i != 0) {
                new Thread(r).start();
    //            new Thread(r).run();
    //            new Thread(r).run();
    //            new Thread(r).run();
    //            new Thread(r).run();
            }
    
    
            RBucket<String> bucket = redissonClient.getBucket(key);
            String s = bucket.get();
            System.out.println("================线程已结束================================" + s);
    
            return s;
        }
    
    }

### 4.3 扩展 ###

4.3.1 丰富的jar支持，尤其是对 Netty NIO框架

4.3.2 丰富的配置机制选择，这里是详细的配置说明

> [https://github.com/redisson/redisson/wiki/2.-Configuration][https_github.com_redisson_redisson_wiki_2.-Configuration]

关于序列化机制中，就有很多

![20210917142249828.png][]

![2021091714225068.png][]

4.3.3 API支持（部分展示），具体的 Redis --> RedissonClient ,可查看这里

> [https://github.com/redisson/redisson/wiki/11.-Redis-commands-mapping][https_github.com_redisson_redisson_wiki_11.-Redis-commands-mapping]

![20210917142250363.png][]

4.3.4 轻便的丰富的锁机制的实现

*  Lock
 *  Fair Lock
 *  MultiLock
 *  RedLock
 *  ReadWriteLock
 *  Semaphore
 *  PermitExpirableSemaphore
 *  CountDownLatch

## **四、基于注解实现的Redis缓存** ##

### 4.1 Maven 和 YML配置 ###

参考 RedisTemplate 配置。另外，还需要额外的配置类

// todo 定义序列化，解决乱码问题
    @EnableCaching
    @Configuration
    @ConfigurationProperties(prefix = "spring.cache.redis")
    public class RedisCacheConfig {
    
        private Duration timeToLive = Duration.ZERO;
    
        public void setTimeToLive(Duration timeToLive) {
            this.timeToLive = timeToLive;
        }
    
        @Bean
        public CacheManager cacheManager(RedisConnectionFactory factory) {
            RedisSerializer<String> redisSerializer = new StringRedisSerializer();
            Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
    
            // 解决查询缓存转换异常的问题
            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（解决乱码的问题）
            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;
        }
    
    }

### 4.2 使用示例 ###

@Transactional
    @Service
    public class ReImpl implements RedisService {
    
        @Resource
        private CustomerRepo customerRepo;
        @Resource
        private StringRedisTemplate stringRedisTemplate;
    
        public static final String REDIS_CUSTOMERS_ONE = "Customers";
    
        public static final String REDIS_CUSTOMERS_ALL = "allList";
    
        // =====================================================================使用Spring cahce 注解方式实现缓存
        // ==================================单个操作
    
        @Override
        @Cacheable(value = "cache:customer", unless = "null == #result",key = "#id")
        public CustomersEntity cacheOne(Integer id) {
            final Optional<CustomersEntity> byId = customerRepo.findById(id);
            return byId.isPresent() ? byId.get() : null;
        }
    
        @Override
        @Cacheable(value = "cache:customer", unless = "null == #result", key = "#id")
        public CustomersEntity cacheOne2(Integer id) {
            final Optional<CustomersEntity> byId = customerRepo.findById(id);
            return byId.isPresent() ? byId.get() : null;
        }
    
         // todo 自定义redis缓存的key,
        @Override
        @Cacheable(value = "cache:customer", unless = "null == #result", key = "#root.methodName + '.' + #id")
        public CustomersEntity cacheOne3(Integer id) {
            final Optional<CustomersEntity> byId = customerRepo.findById(id);
            return byId.isPresent() ? byId.get() : null;
        }
    
        // todo 这里缓存到redis，还有响应页面是String（加了很多转义符\,），不是Json格式
        @Override
        @Cacheable(value = "cache:customer", unless = "null == #result", key = "#root.methodName + '.' + #id")
        public String cacheOne4(Integer id) {
            final Optional<CustomersEntity> byId = customerRepo.findById(id);
            return byId.map(JSONUtil::toJsonStr).orElse(null);
        }
    
         // todo 缓存json，不乱码已处理好,调整序列化和反序列化
        @Override
        @Cacheable(value = "cache:customer", unless = "null == #result", key = "#root.methodName + '.' + #id")
        public CustomersEntity cacheOne5(Integer id) {
            Optional<CustomersEntity> byId = customerRepo.findById(id);
            return byId.filter(obj -> !StrUtil.isBlankIfStr(obj)).orElse(null);
        }
    
    
    
        // ==================================删除缓存
        @Override
        @CacheEvict(value = "cache:customer", key = "'cacheOne5' + '.' + #id")
        public Object del(Integer id) {
            // 删除缓存后的逻辑
            return null;
        }
    
        @Override
        @CacheEvict(value = "cache:customer",allEntries = true)
        public void del() {
    
        }
    
        @CacheEvict(value = "cache:all",allEntries = true)
        public void delall() {
    
        }
        // ==================List操作
    
        @Override
        @Cacheable(value = "cache:all")
        public List<CustomersEntity> cacheList() {
            List<CustomersEntity> all = customerRepo.findAll();
            return all;
        }
    
        // todo 先查询缓存，再校验是否一致，然后更新操作，比较实用，要清楚缓存的数据格式（明确业务和缓存模型数据）
        @Override
        @CachePut(value = "cache:all",unless = "null == #result",key = "#root.methodName")
        public List<CustomersEntity> cacheList2() {
            List<CustomersEntity> all = customerRepo.findAll();
            return all;
        }
    
    }

### 4.3 扩展 ###

基于spring缓存实现

![20210917142250680.png][]

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[https_github.com_javastacks_spring-boot-best-practice]: https://github.com/javastacks/spring-boot-best-practice
[20210917142249229.png]: /images/20220828/3920a957acb94a70bcd2ac01a04de032.png
[20210917142249550.png]: /images/20220828/6072d6bf1c73451e908825564ec2f094.png
[https_github.com_redisson_redisson_wiki_2.-Configuration]: https://github.com/redisson/redisson/wiki/2.-Configuration
[20210917142249828.png]: /images/20220828/acfe7f1df33242b892273ad88dd3f162.png
[2021091714225068.png]: /images/20220828/41b9238817df44339fc20e9ddbde6957.png
[https_github.com_redisson_redisson_wiki_11.-Redis-commands-mapping]: https://github.com/redisson/redisson/wiki/11.-Redis-commands-mapping
[20210917142250363.png]: /images/20220828/4f187c6cc50f40dda3e35acdd2f09042.png
[20210917142250680.png]: /images/20220828/94336b9b9ea44b11847bf5f69116e262.png
[1_000_ _ Java_2021]: https://www.javastack.cn/mst/
[if_ else]: https://www.javastack.cn/article/2021/strategy-pattern-instead-of-if-else/
[Java _ xx _ null]: https://www.javastack.cn/article/2021/intellij-idea-ligatures-settings/
[Spring Boot 2.5]: https://www.javastack.cn/article/2021/spring-boot-2.5-released/
[Java]: http://www.javastack.cn/article/2020/alibaba-release-java-develop-rules-songshan/