社区网站项目4.2 Spring整合Redis

  引入依赖spring-boot-starter-data-redis。

  配置Redis

（1）配置数据库参数

（2）编写配置类，构造RedisTemplate

  访问Redis

（1）redisTemplate.opsForValue()

（2）redisTemplate.opsForHash()

（3）redisTemplate.opsForList()

（4）redisTemplate.opsForSet()

（5）redisTemplate.opsForSet()

（6）redisTemplate.opsForZSet()

  pom.xml里ctrl点击spring-boot-starter-parent，接着ctrl点击spring-boot-dependencies，就能看到spring-boot-dependencies-2.2.5.RELEASE.pom里关于各种jar包的版本。

  搜索RedisAutoConfiguration可以看到Spring对redis做自动配置相关的一个类。

  在application.properties里添加

#RedisProperties
spring.redis.database=11
spring.redis.host=127.0.0.1
spring.redis.port=6379
           

  在config包下新建RedisConfig类

@Bean  //把第三方的redis注入进来
    public RedisTemplate<String,Object> redisTemplate(RedisConnectionFactory factory){
        RedisTemplate<String,Object> template = new RedisTemplate<>();  //实例化这个RedisTemplate
        template.setConnectionFactory(factory);

        //设置key的序列化方式
        template.setKeySerializer(RedisSerializer.string());

        //设置value的序列化方式
        template.setValueSerializer(RedisSerializer.json());

        //设置hash的key的序列化方式
        template.setHashKeySerializer(RedisSerializer.string());

        //设置hash的value的序列化方式
        template.setHashValueSerializer(RedisSerializer.json());

        template.afterPropertiesSet(); //触发生效
        return template;
    }
           

  做测试

@Autowired
    private RedisTemplate redisTemplate;

    @Test
    public void testStrings(){
        String redisKey = "test:count"; //redis里的这个冒号:作用相当于_，用来起名

        redisTemplate.opsForValue().set(redisKey,1);

        System.out.println(redisTemplate.opsForValue().get(redisKey));
        System.out.println(redisTemplate.opsForValue().increment(redisKey));
        System.out.println(redisTemplate.opsForValue().decrement(redisKey));

    }

    @Test
    public void testHashes(){
        String redisKey = "test:user";

        redisTemplate.opsForHash().put(redisKey,"id",1);
        redisTemplate.opsForHash().put(redisKey,"username","zhangsan");

        System.out.println(redisTemplate.opsForHash().get(redisKey,"id"));
        System.out.println(redisTemplate.opsForHash().get(redisKey,"username"));
    }

    @Test
    public void testLists(){
        String redisKey = "test:ids";

        redisTemplate.opsForList().leftPush(redisKey,101);
        redisTemplate.opsForList().leftPush(redisKey,102);
        redisTemplate.opsForList().leftPush(redisKey,103);

        System.out.println(redisTemplate.opsForList().size(redisKey));
        System.out.println(redisTemplate.opsForList().index(redisKey,0));
        System.out.println(redisTemplate.opsForList().range(redisKey,0,2));

        System.out.println(redisTemplate.opsForList().leftPop(redisKey));
        System.out.println(redisTemplate.opsForList().leftPop(redisKey));
        System.out.println(redisTemplate.opsForList().leftPop(redisKey));
    }

    @Test
    public void testSets(){
        String redisKey = "test:teachers";

        redisTemplate.opsForSet().add(redisKey,"刘备","关羽","张飞","赵云","诸葛亮");
        System.out.println(redisTemplate.opsForSet().size(redisKey));
        System.out.println(redisTemplate.opsForSet().pop(redisKey));
        System.out.println(redisTemplate.opsForSet().members(redisKey));
    }

    @Test
    public void testSortedSets(){
        String redisKey = "test:students";

        redisTemplate.opsForZSet().add(redisKey,"唐僧",80);
        redisTemplate.opsForZSet().add(redisKey,"悟空",90);
        redisTemplate.opsForZSet().add(redisKey,"八戒",50);
        redisTemplate.opsForZSet().add(redisKey,"沙僧",70);
        redisTemplate.opsForZSet().add(redisKey,"白龙马",60);

        System.out.println(redisTemplate.opsForZSet().zCard(redisKey));
        System.out.println(redisTemplate.opsForZSet().score(redisKey,"八戒"));
        System.out.println(redisTemplate.opsForZSet().reverseRank(redisKey,"八戒"));  //reverse则按分数从大到小
        System.out.println(redisTemplate.opsForZSet().reverseRange(redisKey,0,2));
    }

    @Test
    public void testKeys(){
        redisTemplate.delete("test:user");

        System.out.println(redisTemplate.hasKey("test:user"));

        redisTemplate.expire("test:students",10, TimeUnit.SECONDS);  //用TimeUnit.SECONDS指明这里的10是以秒为单位
    }

    //多次访问同一个key，可以通过绑定来避免重复传key
    @Test
    public void testBoundOperations(){
        String redisKey = "test:count";
        BoundValueOperations operations = redisTemplate.boundValueOps(redisKey);
        operations.increment();
        operations.increment();
        operations.increment();
        operations.increment();
        operations.increment();
        System.out.println(operations.get());
    }

    //redis的事务不像关系型数据库那样完全满足事务的四个原则，且较少用声明式事务，而多用编程式事务（参考AlphaService)
    @Test
    public void testTransactional(){
        Object obj = redisTemplate.execute(new SessionCallback() {
            @Override
            public Object execute(RedisOperations operations) throws DataAccessException {
                String redisKey = "test:tx";

                operations.multi(); //启用事务

                operations.opsForSet().add(redisKey,"zhangsan");
                operations.opsForSet().add(redisKey,"lisi");
                operations.opsForSet().add(redisKey,"wangwu");

                System.out.println(operations.opsForSet().members(redisKey)); //其实redis是先把上面这些操作存到队列里，还未处理，查询无效，得到空集合[]

                return operations.exec(); //提交事务
            }
        });
        System.out.println(obj); //输出为[1, 1, 1, [lisi, wangwu, zhangsan]]前面的1,1,1表示每次操作影响的行数
    }