SpringBoot线程池
- 2022 年 5 月 19 日
- 筆記
- springboot
1、遇到的场景
- 提高一下插入表的性能优化，两张表，先插旧的表，紧接着插新的表，若是一万多条数据就有点慢了
2、使用步骤
- 用Spring提供的对
ThreadPoolExecutor封装的线程池ThreadPoolTaskExecutor，直接使用注解启用
配置
@Configuration
@EnableAsync
public class ExecutorConfig {
private static final Logger logger = LoggerFactory.getLogger(ExecutorConfig.class);
@Value("${async.executor.thread.core_pool_size}")
private int corePoolSize;
@Value("${async.executor.thread.max_pool_size}")
private int maxPoolSize;
@Value("${async.executor.thread.queue_capacity}")
private int queueCapacity;
@Value("${async.executor.thread.name.prefix}")
private String namePrefix;
@Bean(name = "asyncServiceExecutor")
public Executor asyncServiceExecutor() {
logger.info("start asyncServiceExecutor");
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
// 配置核心线程数
executor.setCorePoolSize(corePoolSize);
// 配置最大线程数
executor.setMaxPoolSize(maxPoolSize);
// 配置队列大小
executor.setQueueCapacity(queueCapacity);
// 配置线程池中的线程的名称前缀
executor.setThreadNamePrefix(namePrefix);
// rejection-policy：当pool已经达到max size的时候，如何处理新任务
// CALLER_RUNS：不在新线程中执行任务，而是有调用者所在的线程来执行
executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
//执行初始化
executor.initialize();
return executor;
}
}
@Value取值配置是在application.properties中的
# 异步线程配置
# 配置核心线程数
async.executor.thread.core_pool_size = 5
# 配置最大线程数
async.executor.thread.max_pool_size = 5
# 配置队列大小
async.executor.thread.queue_capacity = 99999
# 配置线程池中的线程的名称前缀
async.executor.thread.name.prefix = async-service-
Demo测试
- Service接口
public interface AsyncService {
/**
* 执行异步任务
* 可以根据需求，自己加参数拟定
*/
void executeAsync();
}
- Service实现类
@Service
public class AsyncServiceImpl implements AsyncService {
private static final Logger logger = LoggerFactory.getLogger(AsyncServiceImpl.class);
@Override
@Async("asyncServiceExecutor")
public void executeAsync() {
logger.info("start executeAsync");
System.out.println("异步线程要做的事情");
System.out.println("可以在这里执行批量插入等耗时的事情");
logger.info("end executeAsync");
}
}
- 在Controller层注入刚刚的Service即可
@Autowired
private AsyncService asyncService;
@GetMapping("/async")
public void async(){
asyncService.executeAsync();
}
- 使用测试工具测试即可看到相应的打印结果
3、摸索一下
-** 弄清楚线程池当时的情况，有多少线程在执行，多少在队列中等待？**
- 创建一个
ThreadPoolTaskExecutor的子类，在每次提交线程的时候都将当前线程池的运行状况打印出来
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.util.concurrent.ListenableFuture;
import java.util.concurrent.Callable;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;
public class VisiableThreadPoolTaskExecutor extends ThreadPoolTaskExecutor {
private static final Logger logger = LoggerFactory.getLogger(VisiableThreadPoolTaskExecutor.class);
private void showThreadPoolInfo(String prefix) {
ThreadPoolExecutor threadPoolExecutor = getThreadPoolExecutor();
if (null == threadPoolExecutor) {
return;
}
logger.info("{}, {},taskCount [{}], completedTaskCount [{}], activeCount [{}], queueSize [{}]",
this.getThreadNamePrefix(),
prefix,
threadPoolExecutor.getTaskCount(),
threadPoolExecutor.getCompletedTaskCount(),
threadPoolExecutor.getActiveCount(),
threadPoolExecutor.getQueue().size());
}
@Override
public void execute(Runnable task) {
showThreadPoolInfo("1. do execute");
super.execute(task);
}
@Override
public void execute(Runnable task, long startTimeout) {
showThreadPoolInfo("2. do execute");
super.execute(task, startTimeout);
}
@Override
public Future<?> submit(Runnable task) {
showThreadPoolInfo("1. do submit");
return super.submit(task);
}
@Override
public <T> Future<T> submit(Callable<T> task) {
showThreadPoolInfo("2. do submit");
return super.submit(task);
}
@Override
public ListenableFuture<?> submitListenable(Runnable task) {
showThreadPoolInfo("1. do submitListenable");
return super.submitListenable(task);
}
@Override
public <T> ListenableFuture<T> submitListenable(Callable<T> task) {
showThreadPoolInfo("2. do submitListenable");
return super.submitListenable(task);
}
}
-
进过测试发现：
showThreadPoolInfo方法中将任务总数、已完成数、活跃线程数，队列大小都打印出来了，然后Override了父类的execute、submit等方法，在里面调用showThreadPoolInfo方法，这样每次有任务被提交到线程池的时候，都会将当前线程池的基本情况打印到日志中 -
现在修改
ExecutorConfig.java的asyncServiceExecutor方法，将ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor()改为ThreadPoolTaskExecutor executor = new VisiableThreadPoolTaskExecutor()
@Bean(name = "asyncServiceExecutor")
public Executor asyncServiceExecutor() {
logger.info("start asyncServiceExecutor");
// 在这里进行修改
ThreadPoolTaskExecutor executor = new VisiableThreadPoolTaskExecutor();
// 配置核心线程数
executor.setCorePoolSize(corePoolSize);
// 配置最大线程数
executor.setMaxPoolSize(maxPoolSize);
// 配置队列大小
executor.setQueueCapacity(queueCapacity);
// 配置线程池中的线程的名称前缀
executor.setThreadNamePrefix(namePrefix);
// rejection-policy：当pool已经达到max size的时候，如何处理新任务
// CALLER_RUNS：不在新线程中执行任务，而是有调用者所在的线程来执行
executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
//执行初始化
executor.initialize();
return executor;
}
- 经最后测试得到的结果：提交任务到线程池的时候，调用的是
submit(Callable task)这个方法，当前已经提交了3个任务，完成了3个，当前有0个线程在处理任务，还剩0个任务在队列中等待
