Jedis的使用
1、引入依赖
<dependencies>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.1.0</version>
</dependency>
<dependency>
<groupId>commons-pool</groupId>
<artifactId>commons-pool</artifactId>
<version>1.6</version>
</dependency>
</dependencies>
2、测试连接
public class TestPing {
public static void main(String[] args) {
Jedis jedis = new Jedis("192.168.106.130",6379);
jedis.auth("root");
System.out.println(jedis.ping());
}
}
3、基本操作
public class TestAPI {
public static void main(String[] args) {
Jedis jedis = new Jedis("192.168.106.130",6379);
jedis.auth("root");
jedis.set("k1","v1");
jedis.set("k2","v2");
jedis.set("k3","v3");
jedis.set("k4","v4");
System.out.println(jedis.get("k3"));
Set<String> sets = jedis.keys("*");
System.out.println(sets.size());
}
}
public class Test02 {
public static void main(String[] args) {
Jedis jedis = new Jedis("192.168.106.130",6379);
jedis.auth("root");
//key
Set<String> keys = jedis.keys("*");
for (Iterator iterator = keys.iterator(); iterator.hasNext();) {
String key = (String) iterator.next();
System.out.println(key);
}
System.out.println("jedis.exists====>"+jedis.exists("k2"));
System.out.println(jedis.ttl("k1"));
//String
jedis.append("k1","myreids");
System.out.println(jedis.get("k1"));
jedis.set("k4","k4_redis");
jedis.mset("str1","v1","str2","v2","str3","v3");
System.out.println(jedis.mget("str1","str2","str3"));
//list
jedis.lpush("mylist","v1","v2","v3","v4","v5");
List<String> list = jedis.lrange("mylist",0,-1);
for (String element : list) {
System.out.println(element);
}
//set
jedis.sadd("orders","jd001");
jedis.sadd("orders","jd002");
jedis.sadd("orders","jd003");
Set<String> set1 = jedis.smembers("orders");
for (Iterator iterator = set1.iterator(); iterator.hasNext();) {
String string = (String) iterator.next();
System.out.println(string);
}
jedis.srem("orders","jd002");
System.out.println(jedis.smembers("orders").size());
//hash
jedis.hset("hash1","userName","lisi");
System.out.println(jedis.hget("hash1","userName"));
Map<String,String> map = new HashMap<String,String>();
map.put("telphone","13811814763");
map.put("address","atguigu");
map.put("email","abc@163.com");
jedis.hmset("hash2",map);
List<String> result = jedis.hmget("hash2", "telphone","email");
for (String element : result) {
System.out.println(element);
}
//zset
jedis.zadd("zset01",60d,"v1");
jedis.zadd("zset01",70d,"v2");
jedis.zadd("zset01",80d,"v3");
jedis.zadd("zset01",90d,"v4");
Set<String> s1 = jedis.zrange("zset01",0,-1);
for (Iterator iterator = s1.iterator(); iterator.hasNext();) {
String string = (String) iterator.next();
System.out.println(string);
}
}
}
控制台输出:
hash2
str3
hash1
k1
str1
mylist
k2
str2
k3
k4
zset01
orders
jedis.exists====>true
-1
v1myreidsmyreids
[v1, v2, v3]
v5
v4
v3
v2
v1
v5
v4
v3
v2
v1
jd001
jd003
jd002
2
lisi
13811814763
abc@163.com
v1
v2
v3
v4
4、事务
public class Test03 {
public static void main(String[] args) {
Jedis jedis = new Jedis("192.168.106.130",6379);
jedis.auth("root");
Transaction transaction = jedis.multi();
transaction.set("balance","100");
transaction.set("debt","0");
transaction.exec();
//transaction.discard();
}
}
public class TestTX {
public boolean transMethod() throws InterruptedException {
Jedis jedis = new Jedis("192.168.106.130", 6379);
jedis.auth("root");
int balance;// 可用余额
int debt;// 欠额
int amtToSubtract = 10;// 实刷额度
jedis.watch("balance");
jedis.set("balance","5");//模拟其他程序已经修改可用余额
Thread.sleep(7000);
balance = Integer.parseInt(jedis.get("balance"));
if (balance < amtToSubtract) {
jedis.unwatch();
System.out.println("可用余额被修改");
return false;
} else {
System.out.println("开启事务");
Transaction transaction = jedis.multi();
transaction.decrBy("balance", amtToSubtract);
transaction.incrBy("debt", amtToSubtract);
transaction.exec();
balance = Integer.parseInt(jedis.get("balance"));
debt = Integer.parseInt(jedis.get("debt"));
System.out.println("可用余额:" + balance);
System.out.println("欠额:" + debt);
return true;
}
}
/**
* 通俗点讲,watch命令就是标记一个键,如果标记了一个键,
* 在提交事务前如果该键被别人修改过,那事务就会失败,这种情况通常可以在程序中
* 重新再尝试一次。
* 首先标记了键balance,然后检查余额是否足够,不足就取消标记,并不做扣减;
* 足够的话,就启动事务进行更新操作,
* 如果在此期间键balance被其它人修改, 那在提交事务(执行exec)时就会报错,
* 程序中通常可以捕获这类错误再重新执行一次,直到成功。
* @throws InterruptedException
*/
public static void main(String[] args) throws InterruptedException {
TestTX test = new TestTX();
boolean retValue = test.transMethod();
System.out.println("操作是否成功: " + retValue);
}
}
5、主从复制
public class TestMS {
public static void main(String[] args) {
Jedis jedis_M = new Jedis("192.168.106.130",6379);
jedis_M.auth("root");
Jedis jedis_S = new Jedis("192.168.106.130",6380);
jedis_S.auth("root");
jedis_S.slaveof("192.168.106.130",6379);
jedis_M.set("class","1122V2");
String result = jedis_S.get("class");
System.out.println(result);
}
}
6、JedisPool
public class JedisPoolUtil {
private static volatile JedisPool jedisPool = null;
private JedisPoolUtil(){}
public static JedisPool getJedisPoolInstance() {
if(null == jedisPool) {
synchronized (JedisPoolUtil.class) {
if(null == jedisPool) {
JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMaxActive(1000);
poolConfig.setMaxIdle(32);
poolConfig.setMaxWait(100*1000);
poolConfig.setTestOnBorrow(true);
jedisPool = new JedisPool(poolConfig,"192.168.106.130",6379);
}
}
}
return jedisPool;
}
public static void release(JedisPool jedisPool,Jedis jedis) {
if(null != jedis) {
jedisPool.returnResourceObject(jedis);
}
}
}
public class TestPool {
public static void main(String[] args) {
JedisPool jedisPool = JedisPoolUtil.getJedisPoolInstance();
JedisPool jedisPool2 = JedisPoolUtil.getJedisPoolInstance();
System.out.println(jedisPool == jedisPool2);
Jedis jedis = null;
try {
jedis = jedisPool.getResource();
jedis.set("aa","bb");
} catch (Exception e) {
e.printStackTrace();
}finally{
JedisPoolUtil.release(jedisPool, jedis);
}
}
}
常用配置:
JedisPool的配置参数大部分是由JedisPoolConfig的对应项来赋值的。
maxActive:控制一个pool可分配多少个jedis实例,通过pool.getResource()来获取;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。
maxIdle:控制一个pool最多有多少个状态为idle(空闲)的jedis实例;
whenExhaustedAction:表示当pool中的jedis实例都被allocated完时,pool要采取的操作;默认有三种:
WHEN_EXHAUSTED_FAIL —> 表示无jedis实例时,直接抛出NoSuchElementException。
WHEN_EXHAUSTED_BLOCK —> 则表示阻塞住,或者达到maxWait时抛出JedisConnectionException。
WHEN_EXHAUSTED_GROW —> 则表示新建一个jedis实例,也就说设置的maxActive无用。
maxWait:表示当borrow一个jedis实例时,最大的等待时间,如果超过等待时间,则直接抛JedisConnectionException。
testOnBorrow:获得一个jedis实例的时候是否检查连接可用性(ping());如果为true,则得到的jedis实例均是可用的。
testOnReturn:return 一个jedis实例给pool时,是否检查连接可用性(ping())。
testWhileIdle:如果为true,表示有一个idle object evitor线程对idle object进行扫描,如果validate失败,此object会被从pool中drop掉;这一项只有在timeBetweenEvictionRunsMillis大于0时才有意义。
timeBetweenEvictionRunsMillis:表示idle object evitor两次扫描之间要sleep的毫秒数。
numTestsPerEvictionRun:表示idle object evitor每次扫描的最多的对象数。
minEvictableIdleTimeMillis:表示一个对象至少停留在idle状态的最短时间,然后才能被idle object evitor扫描并驱逐;这一项只有在timeBetweenEvictionRunsMillis大于0时才有意义。
softMinEvictableIdleTimeMillis:在minEvictableIdleTimeMillis基础上,加入了至少minIdle个对象已经在pool里面了。如果为-1,evicted不会根据idle time驱逐任何对象。如果minEvictableIdleTimeMillis>0,则此项设置无意义,且只有在timeBetweenEvictionRunsMillis大于0时才有意义。
lifo:borrowObject返回对象时,是采用DEFAULT_LIFO(last in first out,即类似cache的最频繁使用队列),如果为False,则表示FIFO队列。
其中JedisPoolConfig对一些参数的默认设置如下:
testWhileIdle=true
minEvictableIdleTimeMills=60000
timeBetweenEvictionRunsMillis=30000
numTestsPerEvictionRun=-1
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