Jedis如何使用

x33g5p2x  于2021-09-19 转载在 其他  
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Jedis

Jedis是Redis官方推荐的Java连接开发工具。要在Java开发中使用好Redis中间件,必须对Jedis熟悉才能写成漂亮的代码

测试

导入redis的依赖

<!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>3.2.0</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.58</version>
</dependency>

编写测试代码

public class Ping {
	public static void main(String[] args) {
        Jedis jedis = new Jedis("127.0.0.1",6379);
        System.out.println("连接成功");
        //查看服务是否运行
        System.out.println("服务正在运行: "+jedis.ping());
        }
}

常用API

基本操作
public class TestPassword {
    public static void main(String[] args) {
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        //验证密码,如果没有设置密码这段代码省略
        // jedis.auth("password");
        jedis.connect(); //连接
        jedis.disconnect(); //断开连接
        jedis.flushAll(); //清空所有的key
    }
}
对key操作的命令
public class TestKey {
    public static void main(String[] args) {
        Jedis jedis = new Jedis("127.0.0.1", 6379);
        System.out.println("清空数据:"+jedis.flushDB());
        System.out.println("判断某个键是否存在:"+jedis.exists("username"));
        System.out.println("新增<'username','kuangshen'>的键值
        对:"+jedis.set("username", "kuangshen"));
        System.out.println("新增<'password','password'>的键值
        对:"+jedis.set("password", "password"));
        System.out.print("系统中所有的键如下:");
        Set<String> keys = jedis.keys("*");
        System.out.println(keys);
        System.out.println("删除键password:"+jedis.del("password"));
        System.out.println("判断键password是否存
        在:"+jedis.exists("password"));
        System.out.println("查看键username所存储的值的类
        型:"+jedis.type("username"));
        System.out.println("随机返回key空间的一个:"+jedis.randomKey());
        System.out.println("重命名key:"+jedis.rename("username","name"));
        System.out.println("取出改后的name:"+jedis.get("name"));
        System.out.println("按索引查询:"+jedis.select(0));
        System.out.println("删除当前选择数据库中的所有key:"+jedis.flushDB());
        System.out.println("返回当前数据库中key的数目:"+jedis.dbSize());
        System.out.println("删除所有数据库中的所有key:"+jedis.flushAll());
    }
}
对String操作的命令
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();
        } S
        ystem.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));
    }
}
对List操作命令
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));
    }
}
对Set的操作命令
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"));
    }
}
对Hash的操作命令
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<>();
        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"));
    }
}

事务

基本操作

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();
        }
    }
}

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