Spring Cloud Alibaba - 利用Nacos动态调整线程池参数

前提：搭建好cloud alibaba 与 nacos的集成

1 nacos中配置文件内容

core:size: 30
max:size: 50

2 线程配置类

import com.alibaba.cloud.nacos.NacosConfigManager;
import com.alibaba.cloud.nacos.NacosConfigProperties;
import com.alibaba.nacos.api.config.listener.Listener;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.context.annotation.Configuration;
import java.util.concurrent.*;/*** Nacos作为服务配置中心，* 实现一个简单的动态化线程池。* 修改线程池核心线程数、* 最大线程数为例，*/
@RefreshScope
@Configuration
public class DynamicThreadPool implements InitializingBean {@Value("${core.size}")private String coreSize;@Value("${max.size}")private String maxSize;private static ThreadPoolExecutor threadPoolExecutor;@Autowiredprivate NacosConfigManager nacosConfigManager;@Autowiredprivate NacosConfigProperties nacosConfigProperties;@Overridepublic void afterPropertiesSet() throws Exception {//按照nacos配置初始化线程池threadPoolExecutor = new ThreadPoolExecutor(Integer.parseInt(coreSize), Integer.parseInt(maxSize), 10L, TimeUnit.SECONDS,new LinkedBlockingQueue<>(10),new ThreadFactoryBuilder().setNameFormat("c_t_%d").build(),new RejectedExecutionHandler() {@Overridepublic void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {System.out.println("rejected!");}});//nacos配置变更监听nacosConfigManager.getConfigService().addListener("order-service-dev.yml", nacosConfigProperties.getGroup(),new Listener() {@Overridepublic Executor getExecutor() {return null;}@Overridepublic void receiveConfigInfo(String configInfo) {//配置变更，修改线程池配置System.out.println(configInfo);changeThreadPoolConfig(Integer.parseInt(coreSize), Integer.parseInt(maxSize));}});}/*** 打印当前线程池的状态*/public String printThreadPoolStatus() {return String.format("core_size:%s,thread_current_size:%s;" +"thread_max_size:%s;queue_current_size:%s,total_task_count:%s", threadPoolExecutor.getCorePoolSize(),threadPoolExecutor.getActiveCount(), threadPoolExecutor.getMaximumPoolSize(), threadPoolExecutor.getQueue().size(),threadPoolExecutor.getTaskCount());}/*** 给线程池增加任务** @param count*/public void dynamicThreadPoolAddTask(int count) {for (int i = 0; i < count; i++) {int finalI = i;threadPoolExecutor.execute(new Runnable() {@Overridepublic void run() {try {System.out.println(finalI);Thread.sleep(10000);} catch (InterruptedException e) {e.printStackTrace();}}});}}/*** 修改线程池核心参数** @param coreSize* @param maxSize*/private void changeThreadPoolConfig(int coreSize, int maxSize) {threadPoolExecutor.setCorePoolSize(coreSize);threadPoolExecutor.setMaximumPoolSize(maxSize);}
}

3 controller层

@RestController
@RequestMapping("/threadpool")
public class ThreadPoolController {@Autowiredprivate DynamicThreadPool dynamicThreadPool;/*** 打印当前线程池的状态*/@GetMapping("/print")public String printThreadPoolStatus() {return dynamicThreadPool.printThreadPoolStatus();}/*** 给线程池增加任务** @param count*/@GetMapping("/add")public String dynamicThreadPoolAddTask(int count) {dynamicThreadPool.dynamicThreadPoolAddTask(count);return String.valueOf(count);}
}