分布式锁更新

udf-starter-cache-redis/src/main/java/org/itkk/udf/cache/redis/lock/LockResult.java

@@ -0,0 +1,21 @@
+package org.itkk.udf.cache.redis.lock;
+
+import lombok.Data;
+import lombok.ToString;
+
+/**
+ * LockResult
+ */
+@Data
+@ToString
+public class LockResult {
+    /**
+     * lock
+     */
+    private Boolean lock = false;
+
+    /**
+     * value
+     */
+    private String value;
+}

udf-starter-cache-redis/src/main/java/org/itkk/udf/cache/redis/lock/RedisBasedDistributedLock.java

@@ -32,6 +32,59 @@ public class RedisBasedDistributedLock {
     @Autowired
     private CacheRedisProperties cacheRedisProperties;
 
+    /**
+     * lockAndGet
+     *
+     * @param name      name
+     * @param timeout   timeout
+     * @param timeUnit  timeUnit
+     * @param lockValue lockValue
+     * @return LockResult
+     */
+    public LockResult lockAndGet(String name, long timeout, TimeUnit timeUnit, String lockValue) {
+        //定义返回值
+        LockResult lockResult = new LockResult();
+        //获得key
+        String key = getKey(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);
+            } else {
+                //获得缓存值
+                Object cacheValue = redisTemplate.opsForValue().get(key);
+                //设置返回值
+                lockResult.setLock(false);
+                lockResult.setValue(cacheValue == null ? null : (String) cacheValue);
+            }
+        } else {
+            //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);
+                //设置返回值
+                lockResult.setLock(true);
+                lockResult.setValue(lockValue);
+            } else {
+                //获得缓存值
+                Object cacheValue = redisTemplate.opsForValue().get(key);
+                //设置返回值
+                lockResult.setLock(false);
+                lockResult.setValue(cacheValue == null ? null : (String) cacheValue);
+            }
+        }
+        //日志输出
+        log.info("RedisBasedDistributedLock : lock key : {} : {}", key, lockResult.toString());
+        //返回
+        return lockResult;
+    }
+
     /**
      * lock
      *
@@ -44,7 +97,7 @@ public class RedisBasedDistributedLock {
      */
     public <T> boolean lock(String name, long timeout, TimeUnit timeUnit, T lockValue) {
         //获得key
-        String key = cacheRedisProperties.getPrefix() + DISTRIBUTED_LOCK_KEY_PREFIX + name;
+        String key = getKey(name);
         //检查是否是死锁
         if (redisTemplate.hasKey(key)) {
             //获得缓存过期时间
@@ -75,11 +128,21 @@ public class RedisBasedDistributedLock {
      */
     public void unlock(String name) {
         //获得key
-        String key = cacheRedisProperties.getPrefix() + DISTRIBUTED_LOCK_KEY_PREFIX + name;
+        String key = getKey(name);
         //删除缓存
         redisTemplate.delete(key);
         //日志输出
         log.info("RedisBasedDistributedLock : unlock key : {}", key);
     }
 
+    /**
+     * getKey
+     *
+     * @param name name
+     * @return String
+     */
+    private String getKey(String name) {
+        return cacheRedisProperties.getPrefix() + DISTRIBUTED_LOCK_KEY_PREFIX + name;
+    }
+
 }