Java中ThreadLocal的用法和原理 - IT评测·应用市场-qidao123.com技术社区

package com.example.test1.service;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Component;
import java.text.SimpleDateFormat;
import java.util.Date;
@Component
public class AsyncTest {
// 使用threadlocal管理
private static final ThreadLocal<SimpleDateFormat> dateFormatLocal =
ThreadLocal.withInitial(() -> new SimpleDateFormat("yyyy-MM-dd"));
// 不用threadlocal进行管理，用于对比
SimpleDateFormat dateFormat = new SimpleDateFormat();
// 线程名称以task开头
@Async("taskExecutor")
public void formatDateSync(String format, Date date) throws InterruptedException {
SimpleDateFormat simpleDateFormat = dateFormatLocal.get();
simpleDateFormat.applyPattern(format);
// 所有方法都可以直接使用这个变量，而不用根据形参传入
doSomething();
Thread.sleep(1000);
System.out.println("sync " + Thread.currentThread().getName() + " | " + simpleDateFormat.format(date));
// 线程执行完毕，清除数据
dateFormatLocal.remove();
}
// 线程名称以task2开头
@Async("taskExecutor2")
public void formatDate(String format, Date date) throws InterruptedException {
dateFormat.applyPattern(format);
Thread.sleep(1000);
System.out.println("normal " + Thread.currentThread().getName() + " | " + dateFormat.format(date));
}
}

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