Redis key survival time (expire)

A, redis expire command can be used to set a bond of survival time, time to redis automatically deleted after it.

• Set expire survival time (in / sec)
• pexpire provided survival time (/ msec)
• ttl / pttl the remaining lifetime of the review key
• persist cancel survival time
• expireat [key] unix timestamp 1351858600
• pexpireat [key] unix timestamp (in milliseconds) 1351858700000

Second, the application scenarios:

• Limited time promotions
• Website data cache (data for some of the need for regular updates)
• Restriction site visitors access frequency (for example: 1 minute access up to 10 times)

Third, the frequency of access restriction site visitors

package com.chb.common.iface.database.redis;


import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

public class RedisUtil {
	private final String host = "192.168.179.14";
	private final int port = 6379;
	
	public static void main(String[] args) {
		RedisUtil redisUtil = new RedisUtil();
		Jedis jedis = redisUtil.connect1();
		for (int i = 0 ; i < 15; i++) {
			boolean visited = redisUtil.checkLogin(jedis, "192.168.179.11");
			System.out.println("是否允许访问：" + visited);
		}
	}
	
	
	public boolean checkLogin(Jedis jedis, String key) { 
		String value = jedis.get(key);
		if (value == null) {
			jedis.set(key, "0");
			jedis.expire(key, 60); // 设置生存周期60s
		} else {
			int count = Integer.parseInt(value);
			if (count >= 10) {
				System.out.println("当前访问频率过于频繁....");
				return false;
			}
		}
		jedis.incr(key);  // 累加访问次数
		
		return true;
	}
	
	
	
	public Jedis connect() {
		Jedis jedis = new Jedis(host, port);
		return jedis;
	}	
	
	// 使用连接池
	public Jedis connect1() {
		JedisPoolConfig poolConfig = new JedisPoolConfig();
		poolConfig.setMaxTotal(100);//总连接数
		poolConfig.setMaxIdle(10);//空闲链接数
		poolConfig.setMaxWaitMillis(3000);//创建连接的超时时间
		poolConfig.setTestOnBorrow(true);//在创建连接的时候是否会测试
		JedisPool jedisPool = new JedisPool(poolConfig, host, port);
		
		// 通过连接池获取jedis 连接
		Jedis jedis = jedisPool.getResource();
		return jedis;
	}
}