使用Jedis操作redis

Redis是一个开源的Key-Value数据缓存，和Memcached类似。

Redis多种类型的value，包括string(字符串)、list(链表)、set(集合)、zset(sorted set --有序集合)和hash（哈希类型）。

Jedis 是 Redis 官方首选的 Java 客户端开发包 (redis的java版本的客户端实现)

#MAVEN配置

<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.9.0</version>
</dependency>

#JAVA代码

package yyl.example.demo.redis;

import java.util.HashMap;
import java.util.Map;

import redis.clients.jedis.Jedis;

/**
* Jedis 基本用法
*/
public class JedisTest {

public static void main(String[] args) {
Jedis jedis = new Jedis("localhost", 6379);
//jedis.auth("admin");

testString(jedis);
testHash(jedis);
testList(jedis);
testSet(jedis);
testZSet(jedis);

testCommands(jedis);

jedis.disconnect();
}

/** 字符串 */
private static void testString(Jedis jedis) {

System.out.println("#string:");

//# SET key "hello"
System.out.println("> SET key \"hello\"");
System.out.println(jedis.set("key", "hello"));

//# GET key
System.out.println("> GET key");
System.out.println(jedis.get("key"));

System.out.println("> APPEND key \" world\"");
System.out.println(jedis.append("key", " world")); //拼接
System.out.println("> GET key");
System.out.println(jedis.get("key"));

//删除某个键  #DEL key [key ...]
System.out.println("> DEL key");
System.out.println(jedis.del("key")); //删除某个键
System.out.println("> GET key");
System.out.println(jedis.get("key"));

//设置多个键值
//#MSET key1 "Hello" key2 "World"
System.out.println("> MSET key1 \"Hello\" key2 \"World\"");
System.out.println(jedis.mset("key1", "hello", "key2", "World"));

System.out.println("> GET key1");
System.out.println(jedis.get("key1"));
System.out.println("> GET key2");
System.out.println(jedis.get("key2"));

//删除一组键  #DEL key1 key2
System.out.println("> DEL key1 key2");
System.out.println(jedis.del("key1", "key2"));
System.out.println(jedis.get("key2"));

System.out.println("\n");
}

/** 哈希 */
private static void testHash(Jedis jedis) {

System.out.println("#hash:");

System.out.println("> HMSET myhash field1 \"Hello\" field2 \"World\"");
Map<String, String> map = new HashMap<String, String>();
map.put("field1", "Hello");
map.put("field2", "World");
System.out.println(jedis.hmset("myhash", map));

System.out.println("> HMGET myhash field1 field2");
System.out.println(jedis.hmget("myhash", "field1", "field2"));

//返回 key 指定的哈希集中所有的字段和值。
System.out.println("> HGETALL myhash");
System.out.println(jedis.hgetAll("myhash"));

//删除map中的某个键值
System.out.println("> HDEL myhash field1");
System.out.println(jedis.hdel("myhash", "field1"));
System.out.println("> HDEL myhash field1");
System.out.println(jedis.hdel("myhash", "field1"));

//返回 key 指定的哈希集包含的字段的数量
System.out.println("> HLEN myhash");
System.out.println(jedis.hlen("myhash"));

//设置 key 指定的哈希集中指定字段的值
System.out.println("> HSET myhash field1 \"Hello\"");
System.out.println(jedis.hset("myhash", "field1", "Hello"));
System.out.println("> HGET myhash field1");
System.out.println(jedis.hget("myhash", "field1"));

//返回指定的哈希集中所有字段的名字
System.out.println("> HKEYS myhash");
System.out.println(jedis.hkeys("myhash"));

//移除哈希
jedis.del("myhash");
System.out.println("\n");
}

/** 列表 */
private static void testList(Jedis jedis) {

System.out.println("#list:");

//将所有指定的值插入到存于 key 的列表的头部
//如果 key 不存在，那么在进行 push 操作前会创建一个空列表
//如果 key 对应的值不是一个 list 的话，那么会抛出异常
System.out.println("> HKEYS myhash");
System.out.println(jedis.lpush("mylist", "hello"));
System.out.println(jedis.lpush("mylist", "world"));

//返回存储在列表里指定范围内的元素
//(偏移量也可以是负数，表示偏移量是从list尾部开始计数。 例如， -1 表示列表的最后一个元素，-2 是倒数第二个，以此类推)
System.out.println(">  LRANGE mylist 0 -1");
System.out.println(jedis.lrange("mylist", 0, -1));

System.out.println("> DEL mylist");
System.out.println(jedis.del("mylist"));

//向存于 key 的列表的尾部插入所有指定的值
System.out.println("> RPUSH mylist \"1\" \"2\" \"3\" \"4\" \"5\"");
System.out.println(jedis.rpush("mylist", "1", "2", "3", "4", "5"));

//移除并且返回list的第一个元素
System.out.println("> LPOP mylist");
System.out.println(jedis.lpop("mylist"));
System.out.println("> LPOP mylist");
System.out.println(jedis.lpop("mylist"));

//返回存储在 key 里的list的长度
System.out.println("> LLEN mylist");
System.out.println(jedis.llen("mylist"));

//移除列表
jedis.del("mylist");
System.out.println("\n");
}

/** 集合 */
private static void testSet(Jedis jedis) {

System.out.println("#set:");

//添加元素
System.out.println("> SADD myset \"Hello\"");
System.out.println(jedis.sadd("myset", "Hello"));
System.out.println("> SADD myset \"World\"");
System.out.println(jedis.sadd("myset", "World"));
System.out.println("> SADD myset \"World\"");
System.out.println(jedis.sadd("myset", "World"));

//获取集合成员(元素)
System.out.println("> SMEMBERS myset");
System.out.println(jedis.smembers("myset"));

//移除集合
jedis.del("myset");
System.out.println("\n");
}

/** 有序集合 */
private static void testZSet(Jedis jedis) {
System.out.println("#zset:");

System.out.println("> ZADD myzset 3 \"three\"");
System.out.println(jedis.zadd("myzset", 3, "three"));

System.out.println("> ZADD myzset 1 \"two\"");
System.out.println(jedis.zadd("myzset", 2, "two"));

System.out.println("> ZADD myzset 1 \"one\" 1 \"uno\"");
Map<String, Double> scoreMembers = new HashMap<>();
scoreMembers.put("one", 1D);
scoreMembers.put("uno", 1D);
System.out.println(jedis.zadd("myzset", scoreMembers));

System.out.println("> ZRANGE myzset 0 -1");
System.out.println(jedis.zrange("myzset", 0, -1));

//移除集合
jedis.del("myzset");
System.out.println("\n");
}

/** 其他常用操作 */
private static void testCommands(Jedis jedis) {

System.out.println("#COMMANDS:");

//# 返回key所存储的value的数据结构类型
System.out.println("> SET key1 \"value\"");
System.out.println(jedis.set("key1", "value"));
System.out.println("> HSET key2 field \"value\"");
System.out.println(jedis.hset("key2", "field", "value"));
System.out.println("> LPUSH key3 \"value\"");
System.out.println(jedis.lpush("key3", "value"));
System.out.println("> SADD key4 \"value\"");
System.out.println(jedis.sadd("key4", "value"));
System.out.println("> ZADD key5 \"value\"");
System.out.println(jedis.zadd("key5", 0, "value"));

//type可以返回string, list, set, zset , hash, none 等不同的类型。
System.out.println("> TYPE key1");
System.out.println(jedis.type("key1"));
System.out.println("> TYPE key2");
System.out.println(jedis.type("key2"));
System.out.println("> TYPE key3");
System.out.println(jedis.type("key3"));
System.out.println("> TYPE key4");
System.out.println(jedis.type("key4"));
System.out.println("> TYPE key5");
System.out.println(jedis.type("key5"));
System.out.println("> TYPE key6");
System.out.println(jedis.type("key6"));//不存在时返回none

System.out.println("\n");
//设置超时时间
System.out.println("> SET mykey \"hello\"");
System.out.println(jedis.set("mykey", "hello"));

//设置超时时间(单位：秒)
System.out.println("> EXPIRE mykey 2 ");
System.out.println(jedis.expire("mykey", 2));//[EXPIRE key seconds]

//返回key剩余的过期时间(单位：秒)
System.out.println("> TTL mykey ");
System.out.println(jedis.ttl("mykey"));

//返回key剩余的过期时间(单位：毫秒)
System.out.println("> PTTL mykey ");
System.out.println(jedis.pttl("mykey"));

System.out.println("> EXISTS mykey ");
System.out.println(jedis.exists("mykey"));

System.out.println("# sleep 2000 Millisecond!");
try {
Thread.sleep(2 * 1000);
} catch (InterruptedException e) {
}

System.out.println("> EXISTS mykey ");
System.out.println(jedis.exists("mykey"));

//移除
jedis.del("mykey", "key1", "key2", "key3", "key4", "key5");
System.out.println("\n");
}
}