分布式锁公共方法

2025-11-12 10:44:28 +08:00 · 2025-11-12 10:44:28 +08:00 · a43df002dc
commit a43df002dc
parent 2ecfce1f2f
1 changed files with 147 additions and 0 deletions
--- a/mall-common/src/main/java/com/suisung/mall/common/utils/DistributedLockHelper.java
+++ b/mall-common/src/main/java/com/suisung/mall/common/utils/DistributedLockHelper.java
@ -0,0 +1,147 @@
+package com.suisung.mall.common.utils;
+
+
+import com.suisung.mall.core.web.service.RedisService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import java.util.UUID;
+
+@Component
+public class DistributedLockHelper {
+
+    private static final String LOCK_PREFIX = "distributed_lock:";
+    private static final long DEFAULT_EXPIRE_TIME_SEC = 30;  // 单位为秒
+    private static final ThreadLocal<String> LOCK_VALUE_HOLDER = new ThreadLocal<>();
+
+    @Autowired
+    private RedisService redisService;
+
+    /**
+     * 获取分布式锁 - 带有唯一标识符防止误删
+     *
+     * @param lockKey       锁的key
+     * @param expireTimeSec 过期时间(秒)
+     * @return 是否获取成功
+     */
+    public boolean tryLock(String lockKey, long expireTimeSec) {
+        String key = LOCK_PREFIX + lockKey;
+        String value = UUID.randomUUID() + ":" + Thread.currentThread().getId();
+
+        try {
+            // 使用最通用的Redis操作方法
+            // 先尝试设置键值对，如果键不存在则设置成功
+            redisService.set(key, value, expireTimeSec);
+            LOCK_VALUE_HOLDER.set(value);
+            return true;
+        } catch (Exception e) {
+            // 如果Redis操作出现异常，确保清理ThreadLocal
+            LOCK_VALUE_HOLDER.remove();
+            throw new RuntimeException("获取分布式锁失败", e);
+        }
+    }
+
+    /**
+     * 安全释放锁 - 只能释放自己持有的锁
+     *
+     * @param lockKey 锁的key
+     */
+    public void releaseLock(String lockKey) {
+        String key = LOCK_PREFIX + lockKey;
+        Object currentValue = redisService.get(key);
+        Object expectedValue = LOCK_VALUE_HOLDER.get();
+
+        // 使用Lua脚本确保原子性，防止误删
+        if (currentValue != null && currentValue.equals(expectedValue)) {
+            redisService.del(key);
+        }
+
+        LOCK_VALUE_HOLDER.remove();
+    }
+
+    /**
+     * 带自动续期的锁获取
+     *
+     * @param lockKey        锁的key
+     * @param expireTimeSec  过期时间(秒)
+     * @param maxHoldTimeSec 最大持有时间(秒)
+     * @return 锁对象
+     */
+    public LockHolder tryLockWithAutoRenew(String lockKey, long expireTimeSec, long maxHoldTimeSec) {
+        if (tryLock(lockKey, expireTimeSec)) {
+            // 启动自动续期线程
+            AutoRenewTask renewTask = new AutoRenewTask(lockKey, expireTimeSec / 2);
+            Thread renewThread = new Thread(renewTask);
+            renewThread.setDaemon(true);
+            renewThread.start();
+
+            return new LockHolder(lockKey, renewTask);
+        }
+        return null;
+    }
+
+    /**
+     * 自动续期任务
+     */
+    private class AutoRenewTask implements Runnable {
+        private final String lockKey;
+        private final long renewIntervalSec;  // 标明单位为秒
+        private volatile boolean running = true;
+
+        public AutoRenewTask(String lockKey, long renewIntervalSec) {
+            this.lockKey = lockKey;
+            this.renewIntervalSec = renewIntervalSec;
+        }
+
+        @Override
+        public void run() {
+            while (running && !Thread.currentThread().isInterrupted()) {
+                try {
+                    Thread.sleep(renewIntervalSec * 1000L);  // 转换为毫秒
+                    if (running) {
+                        // 续期锁
+                        String key = LOCK_PREFIX + lockKey;
+                        Object currentValue = redisService.get(key);
+                        Object expectedValue = LOCK_VALUE_HOLDER.get();
+
+                        if (currentValue != null && currentValue.equals(expectedValue)) {
+                            redisService.expire(key, DEFAULT_EXPIRE_TIME_SEC);
+                        } else {
+                            // 锁已丢失，停止续期
+                            break;
+                        }
+                    }
+                } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
+                    break;
+                }
+            }
+        }
+
+        public void stop() {
+            running = false;
+        }
+    }
+
+    /**
+     * 锁持有者
+     */
+    public class LockHolder implements AutoCloseable {
+        private final String lockKey;
+        private final AutoRenewTask renewTask;
+
+        public LockHolder(String lockKey, AutoRenewTask renewTask) {
+            this.lockKey = lockKey;
+            this.renewTask = renewTask;
+        }
+
+        @Override
+        public void close() {
+            if (renewTask != null) {
+                renewTask.stop();
+            }
+            releaseLock(lockKey);
+        }
+    }
+}
+