1 在 Java 中操作 Redis

1.1 Redis 的 Java 客户端

• Jedis（官方推荐，且命令语句同 redis 命令）
• Lettuce（底层基于 Netty 多线程框架实现，性能高效）
• Spring Data Redis（对 Jedis 和 Lettuce 进行了高度封装，使用更加简单）

【注】Spring Data Redis 是 Spring 的一部分，对 Redis 底层开发包进行了高度封装，在 Spring 项目中，可以使用 Spring Data Redis 进行简化操作，本项目使用此

1.2 Spring Data Redis 的使用方式

操作步骤：

① 导入 Spring Data Redis 的 maven 坐标

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

② 配置 Redis 数据源

spring:  
    redis:
        host: localhost
        port: 6379
        password: 123456
        database: 0

③ 编写配置类，创建 RedisTemplate 对象

@Configuration
@Slf4j
public class RedisConfiguration {
    @Bean
    public RedisTemplate redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        log.info("开始创建redis模板对象...");
        RedisTemplate redisTemplate = new RedisTemplate();

        //设置redis的连接工厂对象
        redisTemplate.setConnectionFactory(redisConnectionFactory);

        //设置redis (键)的序列化器
        redisTemplate.setKeySerializer(new StringRedisSerializer());

        return redisTemplate;
    }

}

④ 通过 RedisTemplate 对象操作 Redis

public class SpringDataRedisTest {
    @Autowired
    private RedisTemplate redisTemplate;

    @Test
    public void testRedisTemplate() {
        System.out.println(redisTemplate);
        ValueOperations valueOperations = redisTemplate.opsForValue();
        HashOperations hashOperations = redisTemplate.opsForHash();
        ListOperations listOperations = redisTemplate.opsForList();
        SetOperations setoperations = redisTemplate.opsForSet();
        ZSetOperations zSetOperations = redisTemplate.opsForZSet();
    }

    /**
     *操作字符串类型的数据
     */
    @Test
    public void testString() {
        // redis 里的 string 操作命令：set/ get/ setex:设置有效期/ setnx：如果存在key，插入失败
        redisTemplate.opsForValue().set("city","北京");
        String city = (String) redisTemplate.opsForValue().get("city");
        System.out.println(city);
        redisTemplate.opsForValue().set("code",1234,3, TimeUnit.MINUTES);
        redisTemplate.opsForValue().setIfAbsent("lock","1");
        redisTemplate.opsForValue().setIfAbsent("lock","2");
    }

    /**
     * 操作哈希类型数据
     */
    @Test
    public void teshHash() {
        //hset hget hdel hkeys hvals
        HashOperations hashOperations = redisTemplate.opsForHash();
        hashOperations.put("101","name","tom");
        hashOperations.put("101","age","20");

        String name = (String) hashOperations.get("101","name");
        System.out.println(name);

        Set keys = hashOperations.keys("101");
        System.out.println(keys);

        List values = hashOperations.values("101");
        System.out.println(values);

        hashOperations.delete("101","age");
    }

    /**
     * 操作列表类型的数据
     */
    @Test
    public void testList() {
        //lpush lrange rpop llen
        ListOperations listOperations = redisTemplate.opsForList();

        listOperations.leftPushAll("mylist","a","b","c");
        listOperations.leftPush("mylist","d");

        List mylist = listOperations.range("mylist",0,-1);
        System.out.println(mylist);

        listOperations.rightPop("mylist");

        Long size = listOperations.size("mylist");
        System.out.println(size);
    }

    /**
     * 操作集合类型的数据
     */
    @Test
    public void testSet() {
        //sadd smembers scard sinter sunion srem
        SetOperations setOperations = redisTemplate.opsForSet();

        setOperations.add("set1","a","b","c","d");
        setOperations.add("set2","a","b","x","y");

        Set members = setOperations.members("set1");
        System.out.println(members);

        Long size = setOperations.size("set1");
        System.out.println(size);

        Set intersect = setOperations.intersect("set1","set2");
        System.out.println(intersect);

        Set union = setOperations.union("set1","set2");
        System.out.println(union);

        setOperations.remove("set1","a","b");

    }

    /**
     * 操作有序集合类型的数据
     */
    @Test
    public void testZset() {
        //zadd zrange zincrby zrem
        ZSetOperations zSetOperations = redisTemplate.opsForZSet();

        zSetOperations.add("zset1","a",10);
        zSetOperations.add("zset2", "b", 12);
        zSetOperations.add("zset2", "c", 9);

        Set zset1 = zSetOperations.range("zset1" ,0 , -1);
        System.out.println(zset1);

        zSetOperations.incrementScore("zset1","c",10);
        zSetOperations.remove("zset1","a","b");
    }

    /**
     * 通用命令操作
     */
    @Test
    public void testCommon() {
        //keys exists type del
        Set keys = redisTemplate.keys("*");
        System.out.println(keys);

        Boolean name = redisTemplate.hasKey("name");
        Boolean set1 = redisTemplate.hasKey("set1");

        for (Object key :keys) {
            DataType type = redisTemplate.type(key);
            System.out.println(type.name());
        }

        redisTemplate.delete("mylist");
    }

}

2 店铺营业状态设置

2.1 需求分析

产品原型

接口设计 

• 设置营业状态
• 管理端查询营业状态
• 用户端查询营业状态

【项目约定】 

管理端发出的请求，统一使用 /admin 作为前缀；

用户端发出的请求，统一使用 /user 作为前缀

营业状态数据存储方式：

基于 Redis 的字符串来进行存储 ，key：SHOP_STATUS ；value：1/0

【项目约定】 1表示营业，0表示打烊

2.2 代码分析

admin.ShopController.java

@RestController("adminShopController")
@RequestMapping("/admin/shop")
@Api(tags = "店铺相关接口")
@Slf4j
public class ShopController {

    public static final String KEY = "SHOP_STATUS";

    @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 设置店铺的营业状态
     * @param status
     * @return
     */
    @PutMapping("/{status}")
    @ApiOperation("设置店铺的营业状态")
    public Result setStatus(@PathVariable Integer status) {
        log.info("设置店铺的营业状态为：{}",status == 1 ? "营业中" : "打烊中");
        redisTemplate.opsForValue().set(KEY, status);
        return Result.success();
    }

    /**
     * 获取店铺的营业状态
     * @return
     */
    @GetMapping("/status")
    @ApiOperation("获取店铺的营业状态")
    public Result<Integer> getStatus() {
        Integer status = (Integer) redisTemplate.opsForValue().get(KEY);
        log.info("获取到店铺的营业状态为：{}",status == 1 ? "营业中" : "打烊中");
        return null;
    }

}

user.ShopController.java

@RestController("userShopController")
@RequestMapping("/user/shop")
@Api(tags = "店铺相关接口")
@Slf4j
public class ShopController {

    public static final String KEY = "SHOP_STATUS";

    @Autowired
    private RedisTemplate redisTemplate;

    /**
     * 获取店铺的营业状态
     * @return
     */
    @GetMapping("/status")
    @ApiOperation("获取店铺的营业状态")
    public Result<Integer> getStatus() {
        Integer status = (Integer) redisTemplate.opsForValue().get(KEY);
        log.info("获取到店铺的营业状态为：{}",status == 1 ? "营业中" : "打烊中");
        return null;
    }

}