一  zk实现分布式锁的可重入性

1.1 使用ThreadLocal属性

引入ThreadLocal线程局部变量保证zk分布式锁的可重入性。

1.2 关键代码说明

1.3 代码

1.3.1 初始化客户端

1.3.2 分布式锁代码

package com.atguigu.distributed.lock.config;import com.baomidou.mybatisplus.core.toolkit.CollectionUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.zookeeper.*;import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;/*** @ClassName: ZkDistriubtedTHLock* @Description: TODO* @Author: admin* @Date: 2024/01/06 16:07:04 * @Version: V1.0**/
public class ZkDistriubtedTHLock  implements Lock {private static final String ROOT_PATH = "/d-zk";private String path;private ZooKeeper zooKeeper;private static final ThreadLocal<Integer> THREAD_LOCAL = new ThreadLocal<>();public ZkDistriubtedTHLock(ZooKeeper zooKeeper,String lockName) {try {this.zooKeeper = zooKeeper;if (THREAD_LOCAL.get() == null || THREAD_LOCAL.get() == 0){this.path = zooKeeper.create(ROOT_PATH + "/" + lockName + "-", null, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);}} catch (KeeperException e) {e.printStackTrace();} catch (InterruptedException e) {e.printStackTrace();}}@Overridepublic void lock() {Integer flag = THREAD_LOCAL.get();if (flag != null && flag > 0) {THREAD_LOCAL.set(flag + 1);return;}else{try {String preNode = getPreNode(path);// 如果该节点没有前一个节点，说明该节点时最小节点，放行执行业务逻辑if (StringUtils.isEmpty(preNode)){THREAD_LOCAL.set(1);return ;} else {CountDownLatch countDownLatch = new CountDownLatch(1);if (this.zooKeeper.exists(ROOT_PATH + "/" + preNode, new Watcher() {@Overridepublic void process(WatchedEvent event) {System.out.println("当前节点=="+path+" 前一个节点:"+ROOT_PATH + "/" + preNode);countDownLatch.countDown();}}) == null) {System.out.println("监听。。。");THREAD_LOCAL.set(1);return;}// 阻塞。。。。countDownLatch.await();System.out.println("wait。。。");THREAD_LOCAL.set(1);return;}} catch (Exception e) {e.printStackTrace();// 重新检查。是否获取到锁try {Thread.sleep(200);} catch (InterruptedException ex) {ex.printStackTrace();}lock();}}}@Overridepublic void lockInterruptibly() throws InterruptedException {}@Overridepublic boolean tryLock() {return false;}@Overridepublic boolean tryLock(long time, TimeUnit unit) throws InterruptedException {return false;}/*** 获取指定节点的前节点* @param path* @return*/private String getPreNode(String path){try {// 获取当前节点的序列化号Long curSerial = Long.valueOf(StringUtils.substringAfterLast(path, "-"));// 获取根路径下的所有序列化子节点List<String> nodes = this.zooKeeper.getChildren(ROOT_PATH, false);// 判空if (CollectionUtils.isEmpty(nodes)){return null;}// 获取前一个节点Long flag = 0L;String preNode = null;for (String node : nodes) {// 获取每个节点的序列化号Long serial = Long.valueOf(StringUtils.substringAfterLast(node, "-"));if (serial < curSerial && serial > flag){flag = serial;preNode = node;}}return preNode;} catch (KeeperException e) {e.printStackTrace();} catch (InterruptedException e) {e.printStackTrace();}return null;}@Overridepublic void unlock() {try {THREAD_LOCAL.set(THREAD_LOCAL.get() - 1);if (THREAD_LOCAL.get() == 0) {this.zooKeeper.delete(path, 0);THREAD_LOCAL.remove();}} catch (InterruptedException e) {e.printStackTrace();} catch (KeeperException e) {e.printStackTrace();}}@Overridepublic Condition newCondition() {return null;}
}

1.3.3 service

1.3.4 controller

1.4 测试

1.4.1 nginx多节点代理

1.服务

2.nginx

1.4.2 jemeter测试

3.jemeter

4.数据库前后

5.服务节点日志