Jedis对redis的五大类型操作代码详解

本篇主要阐述Jedis对redis的五大类型的操作：字符串、列表、散列、集合、有序集合。

JedisUtil

这里的测试用例采用junit4进行运行，准备代码如下：

private static final String ipAddr = "10.10.195.112";
private static final int port = 6379;
private static Jedis jedis= null;
@BeforeClass
  public static void init()
  {
	jedis = JedisUtil.getInstance().getJedis(ipAddr,port);
}
@AfterClass
  public static void close()
  {
	JedisUtil.getInstance().closeJedis(jedis,ipAddr,port);
}

其中JedisUtil是对jedis做的简单封装，代码如下：

import org.apache.log4j.Logger;
import java.util.HashMap;
import java.util.Map;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
public class JedisUtil
{
	private Logger logger = Logger.getLogger(this.getClass().getName());
	private JedisUtil(){
	}
	private static class RedisUtilHolder{
		private static final JedisUtil instance = new JedisUtil();
	}
	public static JedisUtil getInstance(){
		return RedisUtilHolder.instance;
	}
	private static Map<String,JedisPool> maps = new HashMap<String,JedisPool>();
	private static JedisPool getPool(String ip,int port){
		String key = ip+":"+port;
		JedisPool pool = null;
		if(!maps.containsKey(key))
		    {
			JedisPoolConfig config = new JedisPoolConfig();
			config.setMaxActive(RedisConfig.MAX_ACTIVE);
			config.setMaxIdle(RedisConfig.MAX_IDLE);
			config.setMaxWait(RedisConfig.MAX_WAIT);
			config.setTestOnBorrow(true);
			config.setTestOnReturn(true);
			pool = new JedisPool(config,ip,port,RedisConfig.TIMEOUT);
			maps.put(key,pool);
		} else
		    {
			pool = maps.get(key);
		}
		return pool;
	}
	public Jedis getJedis(String ip,int port)
	  {
		Jedis jedis = null;
		int count = 0;
		do
		    {
			try
			      {
				jedis = getPool(ip,port).getResource();
			}
			catch (Exception e)
			      {
				logger.error("get redis master1 failed!",e);
				getPool(ip,port).returnBrokenResource(jedis);
			}
		}
		while(jedis == null && count<RedisConfig.RETRY_NUM);
		return jedis;
	}
	public void closeJedis(Jedis jedis,String ip,int port){
		if(jedis != null)
		    {
			getPool(ip,port).returnResource(jedis);
		}
	}
}
public class RedisConfig
{
	//可用连接实例的最大数目，默认值为8；
	//如果赋值为-1，则表示不限制；如果pool已经分配了maxActive个jedis实例，则此时pool的状态为exhausted(耗尽)。
	public static int MAX_ACTIVE = 1024;
	//控制一个pool最多有多少个状态为idle(空闲的)的jedis实例，默认值也是8。
	public static int MAX_IDLE = 200;
	//等待可用连接的最大时间，单位毫秒，默认值为-1，表示永不超时。如果超过等待时间，则直接抛出JedisConnectionException；
	public static int MAX_WAIT = 10000;
	public static int TIMEOUT = 10000;
	public static int RETRY_NUM = 5;
}

键操作

@Test public void testKey() throws InterruptedException
  {
    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','zzh'>的键值对："+jedis.set("username","zzh"));
    System.out.println(jedis.exists("name"));
    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("设置键username的过期时间为5s:"+jedis.expire("username",5));
    TimeUnit.SECONDS.sleep(2);
    System.out.println("查看键username的剩余生存时间："+jedis.ttl("username"));
    System.out.println("移除键username的生存时间："+jedis.persist("username"));
    System.out.println("查看键username的剩余生存时间："+jedis.ttl("username"));
    System.out.println("查看键username所存储的值的类型："+jedis.type("username"));
  }

输出结果：

清空数据：OK
判断某个键是否存在：false
新增<'username','zzh'>的键值对：OK
false
新增<'password','password'>的键值对：OK
系统中所有的键如下：[username,password]
删除键password:1
判断键password是否存在：false
设置键username的过期时间为5s:1
查看键username的剩余生存时间：3
移除键username的生存时间：1
查看键username的剩余生存时间：-1
查看键username所存储的值的类型：string

字符串操作

在Redis里面，字符串可以存储三种类型的值：

字节串(byte string)
整数
浮点数
字节串

@Test public void testString() throws InterruptedException
 {
	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","key03"));
	System.out.println("获取多个键值对："+jedis.mget("key01","key04"));
	System.out.println("删除多个键值对："+jedis.del(new String[]{
		"key01","key02"
	}
	));
	System.out.println("获取多个键值对："+jedis.mget("key01","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"));
	TimeUnit.SECONDS.sleep(3);
	System.out.println(jedis.get("key3"));
	System.out.println("===========获取原值，更新为新值==========");
	//GETSET is an atomic set this value and return the old value command.
	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",4));
}

输出结果：

===========增加数据===========
OK
OK
OK
删除键key2:1
获取键key2:null
修改key1:OK
获取key1的值：value1Changed
在key3后面加入值：9
key3的值：value3End
增加多个键值对：OK
获取多个键值对：[value01,value02,value03]
获取多个键值对：[value01,value03,null]
删除多个键值对：2
获取多个键值对：[null,null,value03]
===========新增键值对防止覆盖原先值==============
1
1
0
value1
value2
===========新增键值对并设置有效时间=============
OK
value3
null
===========获取原值，更新为新值==========
value2
key2GetSet
获得key2的值的字串：y2G

memcached和redis同样有append的操作，但是memcached有prepend的操作，redis中并没有。

整数和浮点数

@Test public void testNumber()
  {
    jedis.flushDB();
    jedis.set("key1","1");
    jedis.set("key2","2");
    jedis.set("key3","2.3");
    System.out.println("key1的值："+jedis.get("key1"));
    System.out.println("key2的值："+jedis.get("key2"));
    System.out.println("key1的值加1："+jedis.incr("key1"));
    System.out.println("获取key1的值："+jedis.get("key1"));
    System.out.println("key2的值减1："+jedis.decr("key2"));
    System.out.println("获取key2的值："+jedis.get("key2"));
    System.out.println("将key1的值加上整数5："+jedis.incrBy("key1",5));
    System.out.println("获取key1的值："+jedis.get("key1"));
    System.out.println("将key2的值减去整数5："+jedis.decrBy("key2",5));
    System.out.println("获取key2的值："+jedis.get("key2"));
  }

输出结果：

key1的值：1
key2的值：2
key1的值加1：2
获取key1的值：2
key2的值减1：1
获取key2的值：1
将key1的值加上整数5：7
获取key1的值：7
将key2的值减去整数5：-4
获取key2的值：-4

在redis2.6或以上版本中有这个命令：incrbyfloat，即将键存储的值加上浮点数amount，jedis-2.1.0中不支持这一操作。

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