From 790255f73351a4e1dd93e565ccc7f612b989d8eb Mon Sep 17 00:00:00 2001
From: wangkang <wangkangit@163.com>
Date: Thu, 21 Dec 2017 08:52:37 +0800
Subject: [PATCH] =?UTF-8?q?=E5=9F=BA=E4=BA=8Eredis=E7=9A=84=E5=88=86?=
 =?UTF-8?q?=E5=B8=83=E5=BC=8F=E9=94=81?=
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---
 .../redis/lock/RedisBasedDistributedLock.java | 79 +++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 udf-starter-cache-redis/src/main/java/org/itkk/udf/cache/redis/lock/RedisBasedDistributedLock.java

diff --git a/udf-starter-cache-redis/src/main/java/org/itkk/udf/cache/redis/lock/RedisBasedDistributedLock.java b/udf-starter-cache-redis/src/main/java/org/itkk/udf/cache/redis/lock/RedisBasedDistributedLock.java
new file mode 100644
index 0000000..ca5c49f
--- /dev/null
+++ b/udf-starter-cache-redis/src/main/java/org/itkk/udf/cache/redis/lock/RedisBasedDistributedLock.java
@@ -0,0 +1,79 @@
+package org.itkk.udf.cache.redis.lock;
+
+import org.itkk.udf.cache.redis.CacheRedisProperties;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * RedisBasedDistributedLock
+ */
+@Component
+public class RedisBasedDistributedLock {
+
+    /**
+     * DISTRIBUTED_LOCK_KEY_PREFIX
+     */
+    private static final String DISTRIBUTED_LOCK_KEY_PREFIX = ":DISTRIBUTED_LOCK:";
+
+    /**
+     * redisTemplate
+     */
+    @Autowired
+    private RedisTemplate<Object, Object> redisTemplate;
+
+    /**
+     * cacheRedisProperties
+     */
+    @Autowired
+    private CacheRedisProperties cacheRedisProperties;
+
+    /**
+     * lock
+     *
+     * @param name      name
+     * @param timeout   timeout
+     * @param timeUnit  timeUnit
+     * @param lockValue lockValue
+     * @param <T>       <T>
+     * @return boolean
+     */
+    public <T> boolean lock(String name, long timeout, TimeUnit timeUnit, T lockValue) {
+        //获得key
+        String key = cacheRedisProperties.getPrefix() + DISTRIBUTED_LOCK_KEY_PREFIX + name;
+        //检查是否是死锁
+        if (redisTemplate.hasKey(key)) {
+            //获得缓存过期时间
+            long expiration = redisTemplate.getExpire(key);
+            //如果等于-1,则代表死锁
+            if (expiration == -1) {
+                //删除缓存
+                redisTemplate.delete(key);
+            }
+        }
+        //创建锁
+        boolean lock = redisTemplate.opsForValue().setIfAbsent(key, lockValue);
+        //锁成功
+        if (lock) {
+            //设置超时时间
+            redisTemplate.expire(key, timeout, timeUnit);
+        }
+        //返回
+        return lock;
+    }
+
+    /**
+     * unlock
+     *
+     * @param name name
+     */
+    public void unlock(String name) {
+        //获得key
+        String key = cacheRedisProperties.getPrefix() + DISTRIBUTED_LOCK_KEY_PREFIX + name;
+        //删除缓存
+        redisTemplate.delete(key);
+    }
+
+}