限流(三)Redis+lua分布式限流

./redis-server 启动服务端
./redis-cli 启动客户端
./redis-cli shutdown 关闭服务
keys * 查看所有key
get 键 根据键获取值

local key = KEYS[1] --限流KEY（一秒一个）
local limit = tonumber(ARGV[1]) --限流大小
local current = tonumber(redis.call('get', key) or "0")
if current + 1 > limit then --如果超出限流大小
    return 0
else --请求数+1，并设置2秒过期
    redis.call("INCRBY", key,"1")
    redis.call("expire", key,"1")
    return 1
end

 <dependency>
    <groupId>redis.clientsgroupId>
    <artifactId>jedisartifactId>
    <version>2.9.0version>
dependency>

<dependency>
    <groupId>commons-iogroupId>
    <artifactId>commons-ioartifactId>
    <version>2.4version>
dependency>

import org.apache.commons.io.FileUtils;
import redis.clients.jedis.Jedis;

import java.io.File;
import java.io.IOException;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;

/**
 * @author lay
 * @date 2018/5/22.
 * @time 17:48
 */
public class RedisLua {

    public static void main(String[] args) {
        final CountDownLatch latch = new CountDownLatch(1);

        for (int i = 0; i <7; i++) {
            new Thread(new Runnable() {
                public void run() {
                    try {
                        latch.await();
                        System.out.println(accquire());
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }).start();

        }

        latch.countDown();
    }

    public static boolean accquire() throws IOException, URISyntaxException {
        Jedis jedis = new Jedis("127.0.0.1");
        File luaFile = new File(RedisLua.class.getResource("/").toURI().getPath() + "limit.lua");
        String luaScript = FileUtils.readFileToString(luaFile);

        String key = "ip:" + System.currentTimeMillis()/1000; // 当前秒
        String limit = "5"; // 最大限制
        List keys = new ArrayList();
        keys.add(key);
        List args = new ArrayList();
        args.add(limit);
        Long result = (Long)(jedis.eval(luaScript, keys, args)); // 执行lua脚本，传入参数
        return result == 1;
    }
}

true
true
false
true
false
true
true