<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.1.0</version>
</dependency>
public static void main(String[] args) {
Jedis jedis = new Jedis("127.0.0.1",6379);
//授权
jedis.auth("123456");
//输出PONG,redis连通成功
System.out.println(jedis.ping());
jedis.set("k1","v1");
jedis.set("k2","v2");
jedis.set("k3","v3");
Set<String> keys = jedis.keys("*");
keys.forEach(u-> System.out.println(u));
System.out.println("jedis.exists:" + jedis.exists("k2"));
//一次放入多个String
jedis.mset("m1","vm1","m2","vm2","m3","vm3");
Set<String> keys1 = jedis.keys("*");
keys.forEach(u-> System.out.print(u+" "));
System.out.println("");
// list
jedis.lpush("mylist","1","2","3","4");
List<String> list=jedis.lrange("mylist",0,-1);
System.out.println(list);
//set
jedis.sadd("myset","hello");
jedis.sadd("myset","hello");
jedis.sadd("myset","hello1");
jedis.sadd("myset","hello2");
Set<String> set=jedis.smembers("myset");
System.out.println(set);
// hash
jedis.hset("myhash","username","lcg");
jedis.hset("myhash","username","lcg1");
jedis.hset("myhash","password","123456");
jedis.hset("myhash1","username","lcg1");
jedis.hset("myhash1","username","lcg111");
jedis.hset("myhash1","password","12345611");
jedis.hset("myhash2","username","lcg1");
jedis.hset("myhash2","username","lcg1213");
jedis.hset("myhash2","password","123456afewf");
List<String> list1=jedis.hmget("myhash","username","password");
Map<String,String> map1=jedis.hgetAll("myhash2");
System.out.println(list1);
System.out.println(map1);
//zset
jedis.zadd("zset01", 60d, "v1");
jedis.zadd("zset01", 170d, "v2");
jedis.zadd("zset01", 180d, "v3");
jedis.zadd("zset01", 90d, "v4");
Set<String> s1 = jedis.zrange("zset01", 0, -1);
System.out.println(s1);
}
package com.example.redis;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.Response;
import redis.clients.jedis.Transaction;
import java.util.List;
public class TestRedisTransaction {
public static void main(String[] args) throws InterruptedException {
Jedis jedis = new Jedis(“127.0.0.1”,6379);
//授权
jedis.auth(“123456”);
//输出PONG,redis连通成功
System.out.println(jedis.ping());
//事务
Transaction transaction=jedis.multi();
Response<String> response = transaction.get("serialNum");
transaction.set("serialNum", "s002");
transaction.set("serialNum", "s004");
response = transaction.get("serialNum");
transaction.lpush("list3", "a");
transaction.lpush("list3", "b");
transaction.lpush("list3", "c");
transaction.exec();
// 2 transaction.discard();
System.out.println("serialNum***********" + response.get());
List<String> list= jedis.lrange("list3",0,-1);
System.out.println(list);
/**
* 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
*/
TestRedisTransaction t1=new TestRedisTransaction();
boolean retValue = t1.transMethod();
System.out.println("main retValue-------: " + retValue);
}
public static boolean transMethod() throws InterruptedException {
Jedis jedis = new Jedis("127.0.0.1", 6379);
jedis.auth("123456");
int balance;// 可用余额
int debt;// 欠额
int amtToSubtract = 10;// 实刷额度
jedis.set("balance","100");
jedis.set("debt","0");
jedis.watch("balance");
// Thread.sleep(7000); //让该线程休眠七秒,然后在其他地方例如再开启一个redis-cli修改balance,就会报错
balance = Integer.parseInt(jedis.get("balance"));
if (balance < amtToSubtract) {
jedis.unwatch();
System.out.println("modify");
return false;
} else {
System.out.println("***********transaction");
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("*******" + balance);
System.out.println("*******" + debt);
return true;
}
}
}
package com.example.redis;
import redis.clients.jedis.Jedis;
public class MasterSlave {
public static void main(String[] args) {
//主从复制
Jedis jedis_M = new Jedis("127.0.0.1", 6379);
Jedis jedis_S = new Jedis("127.0.0.1", 6380);
jedis_S.slaveof("127.0.0.1", 6379);
jedis_M.set("class", "1122V2");
String result = jedis_S.get("class");//可能有延迟,需再次启动才能使用
System.out.println(result);
}
}
池化技术应用:Java多线程知识模块的线程池、Mysql,Redis的数据库连接池、http连接池等等。
降低资源消耗:通过重复利用已创建的线程降低线程创建和销毁造成的消耗。
提高响应速度:当任务到达时,可以不需要等待线程创建就能立即执行。
提高线程的可管理性:线程是稀缺资源,如果无限制的创建,不仅会消耗系统资源,还会降低系统的稳定性,使用线程池可以进行统一的分配,监控和调优。
package com.example.redis;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
public class JedisPoolUtil {
private static volatile JedisPool jedisPool=null;
private JedisPoolUtil(){}
public static JedisPool getJedisPoolInstance(){
if(jedisPool==null){
synchronized (JedisPoolUtil.class){
if(jedisPool==null){
JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMaxActive(1000);
poolConfig.setMaxIdle(32);
poolConfig.setMaxWait(100 * 1000);
poolConfig.setTestOnBorrow(true);
//redis线程池和主从复制不是一回事情!
//redis线程池是针对一个ip+port的redis而言,即同一个redis的不同redis-cli,而主从复制是针对不同的redis-server
jedisPool=new JedisPool(poolConfig,"121.37.68.120",6379);
}
}
}
return jedisPool;
}
public static void release(JedisPool jedisPool, Jedis jedis) {
if (null != jedis) {
jedisPool.returnResourceObject(jedis);
}
}
}
Test
package com.example.redis;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
public class RedisPool {
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("testaa", "testaa");
} catch (Exception e) {
e.printStackTrace();
} finally {
JedisPoolUtil.release(jedisPool, jedis);
}
}
}