7.Jedis

Jedis

使用java来操作Redis

什么是Jedis ？
Redis官方推荐的java连接开发工具

测试

1. 导入对应依赖

<!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>2.9.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.74</version>
</dependency>

2. 编码测试

• 连接数据库
• 操作命令
• 断开连接

public class TestPing {
    public static void main(String[] args) {
        // 1. new Jedis对象
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        System.out.println(jedis.ping());
    }
}

输出：

常用API

---

String

public class TestString {
    public static void main(String[] args) {
        Jedis jedis = new Jedis("127.0.0.1", 6379);

        jedis.flushDB();
        System.out.println("===========增加数据===========");
        System.out.println(jedis.set("key1","value1"));
        System.out.println(jedis.set("key2","value2"));
        System.out.println(jedis.set("key3", "value3"));
        System.out.println("删除键key2:"+jedis.del("key2"));
        System.out.println("获取键key2:"+jedis.get("key2"));
        System.out.println("修改key1:"+jedis.set("key1", "value1Changed"));
        System.out.println("获取key1的值："+jedis.get("key1"));
        System.out.println("在key3后面加入值："+jedis.append("key3", "End"));
        System.out.println("key3的值："+jedis.get("key3"));
        System.out.println("增加多个键值对："+jedis.mset("key01","value01","key02","value02","key03","value03"));
        System.out.println("获取多个键值对："+jedis.mget("key01","key02","key03"));
        System.out.println("获取多个键值对："+jedis.mget("key01","key02","key03","key04"));
        System.out.println("删除多个键值对："+jedis.del("key01","key02"));
        System.out.println("获取多个键值对："+jedis.mget("key01","key02","key03"));

        jedis.flushDB();
        System.out.println("===========新增键值对防止覆盖原先值==============");
        System.out.println(jedis.setnx("key1", "value1"));
        System.out.println(jedis.setnx("key2", "value2"));
        System.out.println(jedis.setnx("key2", "value2-new"));
        System.out.println(jedis.get("key1"));
        System.out.println(jedis.get("key2"));

        System.out.println("===========新增键值对并设置有效时间=============");
        System.out.println(jedis.setex("key3", 2, "value3"));
        System.out.println(jedis.get("key3"));
        try {
            TimeUnit.SECONDS.sleep(3);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(jedis.get("key3"));

        System.out.println("===========获取原值，更新为新值==========");
        System.out.println(jedis.getSet("key2", "key2GetSet"));
        System.out.println(jedis.get("key2"));

        System.out.println("获得key2的值的字串："+jedis.getrange("key2", 2, 4));
    }

List

public class TestList {
    public static void main(String[] args) {
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        jedis.flushDB();
        System.out.println("===========添加一个list===========");
        jedis.lpush("collections", "ArrayList", "Vector", "Stack", "HashMap", "WeakHashMap", "LinkedHashMap");
        jedis.lpush("collections", "HashSet");
        jedis.lpush("collections", "TreeSet");
        jedis.lpush("collections", "TreeMap");
        System.out.println("collections的内容："+jedis.lrange("collections", 0, -1));//-1代表倒数第一个元素，-2代表倒数第二个元素,end为-1表示查询全部
        System.out.println("collections区间0-3的元素："+jedis.lrange("collections",0,3));
        System.out.println("===============================");
        // 删除列表指定的值 ，第二个参数为删除的个数（有重复时），后add进去的值先被删，类似于出栈
        System.out.println("删除指定元素个数："+jedis.lrem("collections", 2, "HashMap"));
        System.out.println("collections的内容："+jedis.lrange("collections", 0, -1));
        System.out.println("删除下表0-3区间之外的元素："+jedis.ltrim("collections", 0, 3));
        System.out.println("collections的内容："+jedis.lrange("collections", 0, -1));
        System.out.println("collections列表出栈（左端）："+jedis.lpop("collections"));
        System.out.println("collections的内容："+jedis.lrange("collections", 0, -1));
        System.out.println("collections添加元素，从列表右端，与lpush相对应："+jedis.rpush("collections", "EnumMap"));
        System.out.println("collections的内容："+jedis.lrange("collections", 0, -1));
        System.out.println("collections列表出栈（右端）："+jedis.rpop("collections"));
        System.out.println("collections的内容："+jedis.lrange("collections", 0, -1));
        System.out.println("修改collections指定下标1的内容："+jedis.lset("collections", 1, "LinkedArrayList"));
        System.out.println("collections的内容："+jedis.lrange("collections", 0, -1));
        System.out.println("===============================");
        System.out.println("collections的长度："+jedis.llen("collections"));
        System.out.println("获取collections下标为2的元素："+jedis.lindex("collections", 2));
        System.out.println("===============================");
        jedis.lpush("sortedList", "3","6","2","0","7","4");
        System.out.println("sortedList排序前："+jedis.lrange("sortedList", 0, -1));
        System.out.println(jedis.sort("sortedList"));
        System.out.println("sortedList排序后："+jedis.lrange("sortedList", 0, -1));
    }
}

Set

public class TestSet {
    public static void main(String[] args) {
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        jedis.flushDB();
        System.out.println("============向集合中添加元素（不重复）============");
        System.out.println(jedis.sadd("eleSet", "e1","e2","e4","e3","e0","e8","e7","e5"));
        System.out.println(jedis.sadd("eleSet", "e6"));
        System.out.println(jedis.sadd("eleSet", "e6"));
        System.out.println("eleSet的所有元素为："+jedis.smembers("eleSet"));
        System.out.println("删除一个元素e0："+jedis.srem("eleSet", "e0"));
        System.out.println("eleSet的所有元素为："+jedis.smembers("eleSet"));
        System.out.println("删除两个元素e7和e6："+jedis.srem("eleSet", "e7","e6"));
        System.out.println("eleSet的所有元素为："+jedis.smembers("eleSet"));
        System.out.println("随机的移除集合中的一个元素："+jedis.spop("eleSet"));
        System.out.println("随机的移除集合中的一个元素："+jedis.spop("eleSet"));
        System.out.println("eleSet的所有元素为："+jedis.smembers("eleSet"));
        System.out.println("eleSet中包含元素的个数："+jedis.scard("eleSet"));
        System.out.println("e3是否在eleSet中："+jedis.sismember("eleSet", "e3"));
        System.out.println("e1是否在eleSet中："+jedis.sismember("eleSet", "e1"));
        System.out.println("e1是否在eleSet中："+jedis.sismember("eleSet", "e5"));
        System.out.println("=================================");
        System.out.println(jedis.sadd("eleSet1", "e1","e2","e4","e3","e0","e8","e7","e5"));
        System.out.println(jedis.sadd("eleSet2", "e1","e2","e4","e3","e0","e8"));
        System.out.println("将eleSet1中删除e1并存入eleSet3中："+jedis.smove("eleSet1", "eleSet3", "e1"));//移到集合元素
        System.out.println("将eleSet1中删除e2并存入eleSet3中："+jedis.smove("eleSet1", "eleSet3", "e2"));
        System.out.println("eleSet1中的元素："+jedis.smembers("eleSet1"));
        System.out.println("eleSet3中的元素："+jedis.smembers("eleSet3"));
        System.out.println("============集合运算=================");
        System.out.println("eleSet1中的元素："+jedis.smembers("eleSet1"));
        System.out.println("eleSet2中的元素："+jedis.smembers("eleSet2"));
        System.out.println("eleSet1和eleSet2的交集:"+jedis.sinter("eleSet1","eleSet2"));
        System.out.println("eleSet1和eleSet2的并集:"+jedis.sunion("eleSet1","eleSet2"));
        System.out.println("eleSet1和eleSet2的差集:"+jedis.sdiff("eleSet1","eleSet2"));//eleSet1中有，eleSet2中没有
        jedis.sinterstore("eleSet4","eleSet1","eleSet2");//求交集并将交集保存到dstkey的集合
        System.out.println("eleSet4中的元素："+jedis.smembers("eleSet4"));
    }
}

Hash

public class TestHash {
    public static void main(String[] args) {
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        jedis.flushDB();
        Map<String,String> map = new HashMap<String,String>();
        map.put("key1","value1");
        map.put("key2","value2");
        map.put("key3","value3");
        map.put("key4","value4");
        //添加名称为hash（key）的hash元素
        jedis.hmset("hash",map);
        //向名称为hash的hash中添加key为key5，value为value5元素
        jedis.hset("hash", "key5", "value5");
        System.out.println("散列hash的所有键值对为："+jedis.hgetAll("hash"));//return Map<String,String>
        System.out.println("散列hash的所有键为："+jedis.hkeys("hash"));//return Set<String>
        System.out.println("散列hash的所有值为："+jedis.hvals("hash"));//return List<String>
        System.out.println("将key6保存的值加上一个整数，如果key6不存在则添加key6："+jedis.hincrBy("hash", "key6", 6));
        System.out.println("散列hash的所有键值对为："+jedis.hgetAll("hash"));
        System.out.println("将key6保存的值加上一个整数，如果key6不存在则添加key6："+jedis.hincrBy("hash", "key6", 3));
        System.out.println("散列hash的所有键值对为："+jedis.hgetAll("hash"));
        System.out.println("删除一个或者多个键值对："+jedis.hdel("hash", "key2"));
        System.out.println("散列hash的所有键值对为："+jedis.hgetAll("hash"));
        System.out.println("散列hash中键值对的个数："+jedis.hlen("hash"));
        System.out.println("判断hash中是否存在key2："+jedis.hexists("hash","key2"));
        System.out.println("判断hash中是否存在key3："+jedis.hexists("hash","key3"));
        System.out.println("获取hash中的值："+jedis.hmget("hash","key3"));
        System.out.println("获取hash中的值："+jedis.hmget("hash","key3","key4"));
    }
}

Zset

事务

public class TestMulti {
    public static void main(String[] args) {
        //创建客户端连接服务端，redis服务端需要被开启
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        jedis.flushDB();

        JSONObject jsonObject = new JSONObject();
        jsonObject.put("hello", "world");
        jsonObject.put("name", "java");
        //开启事务
        Transaction multi = jedis.multi();
        String result = jsonObject.toJSONString();
        try{
            //向redis存入一条数据
            multi.set("json", result);
            //再存入一条数据
            multi.set("json2", result);
            //这里引发了异常，用0作为被除数
            int i = 100/0;
            //如果没有引发异常，执行进入队列的命令
            multi.exec();
        }catch(Exception e){
            e.printStackTrace();
            //如果出现异常，回滚
            multi.discard();
        }finally{
            System.out.println(jedis.get("json"));
            System.out.println(jedis.get("json2"));
            //最终关闭客户端
            jedis.close();
        }
    }
}