Revision of Spring boot 中 Redis 实现简易分布式锁

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waynelone revidoval tento gist 5 months ago. Přejít na revizi

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RedisDistributedLockImpl.jav přejmenováno na RedisDistributedLockImpl.java

Soubor přejmenován beze změn

waynelone revidoval tento gist 5 months ago. Přejít na revizi

1 file changed, 0 insertions, 0 deletions

gistfile1.txt přejmenováno na RedisDistributedLockImpl.jav

Soubor přejmenován beze změn

waynelone revidoval tento gist 5 months ago. Přejít na revizi

3 files changed, 96 insertions

Demo.java(vytvořil soubor)

		@@ -0,0 +1,14 @@
1	+	DistributedLockParam lockParam = null;
2	+	try {
3	+	lockParam = new DistributedLockParam("test:lock:key");
4	+	boolean lockOk = distributedLock.lock(lockParam);
5	+	if (!lockOk) {
6	+	return new Result().error("系统繁忙，请稍候重试");
7	+	}
8	+	// 执行业务逻辑
9	+	} finally {
10	+	// 最后强制解锁
11	+	if (lockParam != null) {
12	+	distributedLock.unlock(lockParam);
13	+	}
14	+	}

DistributedLock.java(vytvořil soubor)

		@@ -0,0 +1,21 @@
1	+	/**
2	+	* 分布式锁
3	+	*/
4	+	public interface DistributedLock {
5	+
6	+	/**
7	+	* 加锁
8	+	*
9	+	* @param param 加锁参数
10	+	* @return 加锁是否成功
11	+	*/
12	+	boolean lock(DistributedLockParam param);
13	+
14	+	/**
15	+	* 解锁
16	+	*
17	+	* @param param 加锁参数
18	+	* @return 解锁是否成功
19	+	*/
20	+	boolean unlock(DistributedLockParam param);
21	+	}

gistfile1.txt(vytvořil soubor)

		@@ -0,0 +1,61 @@
1	+	import lombok.RequiredArgsConstructor;
2	+	import org.apache.commons.lang3.StringUtils;
3	+	import org.slf4j.Logger;
4	+	import org.slf4j.LoggerFactory;
5	+	import org.springframework.data.redis.core.RedisTemplate;
6	+	import org.springframework.data.redis.core.script.DefaultRedisScript;
7	+	import org.springframework.data.redis.core.script.RedisScript;
8	+	import org.springframework.stereotype.Service;
9	+
10	+	import java.util.Collections;
11	+	import java.util.concurrent.TimeUnit;
12	+
13	+	/**
14	+	* Redis Lock
15	+	**/
16	+	@Service
17	+	@RequiredArgsConstructor
18	+	public class RedisDistributedLockImpl implements DistributedLock {
19	+
20	+	private static final Logger log = LoggerFactory.getLogger(RedisDistributedLockImpl.class);
21	+
22	+	private static final String UNLOCK_SCRIPT = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
23	+	private static final Long UNLOCK_SUCCESS = 1L;
24	+
25	+	private final RedisTemplate<String, String> redisTemplate;
26	+
27	+	@Override
28	+	@SuppressWarnings({"BusyWait", "java:S2142"})
29	+	public boolean lock(DistributedLockParam param) {
30	+	final long tryLockEndTime = param.getTryLockTime() + System.currentTimeMillis();
31	+	while (true) {
32	+	//判断是否超过了，尝试获取锁的时间
33	+	if (System.currentTimeMillis() > tryLockEndTime) {
34	+	return false;
35	+	}
36	+
37	+	// 尝试获取锁
38	+	Boolean ok = redisTemplate.opsForValue().setIfAbsent(param.getKey(), param.getValue(), param.getHoldLockTime(), TimeUnit.MILLISECONDS);
39	+	if (Boolean.TRUE.equals(ok)) {
40	+	return true;
41	+	}
42	+
43	+	try {
44	+	//获得锁失败，休眠50毫秒再去尝试获得锁,避免一直请求redis，导致redis cpu飙升
45	+	Thread.sleep(50);
46	+	} catch (InterruptedException e) {
47	+	log.info(e.getMessage());
48	+	}
49	+	}
50	+	}
51	+
52	+	@Override
53	+	public boolean unlock(DistributedLockParam param) {
54	+	if (StringUtils.isBlank(param.getKey()) \|\| StringUtils.isBlank(param.getValue())) {
55	+	return false;
56	+	}
57	+	RedisScript<Long> redisScript = new DefaultRedisScript<>(UNLOCK_SCRIPT, Long.class);
58	+	Long result = redisTemplate.execute(redisScript, Collections.singletonList(param.getKey()), param.getValue());
59	+	return UNLOCK_SUCCESS.equals(result);
60	+	}
61	+	}

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