1 spring bean 指定顺序初始化 @BeforeConfigution

2 main 与 test 测试多线程问题

2.1 案例代码

package latest.practice.demo.thread;
import org.junit.jupiter.api.Test;
import java.util.Date;
import java.util.concurrent.TimeUnit;
/**
 * thread 测试
 *
 * @author Bruce
 * @date 2021/8/23 14:30
 */
public class ThreadDemo {
    /**
     * 测试守护线程
     */
    @Test
    public void testDaemonThread() throws InterruptedException {
        Date now = new Date();
        System.out.println(">>>>>>>>>> thread start..." + Thread.currentThread().getName() + "," + now);
        Thread thread = new Thread(() -> {
            System.out.println(">>>>>>>>>> testDaemonThread start..." + Thread.currentThread().getName());
            try {
                TimeUnit.SECONDS.sleep(2L);
            } catch (InterruptedException e) {
                e.printStackTrace();
            } finally {
                System.out.println(">>>>> testDaemonThread finally");
            }
            System.out.println(">>>>>>>>>> testDaemonThread end..." + Thread.currentThread().getName());
        }, "testDaemonThread");
        thread.setDaemon(true);
        thread.start();
//        thread.join();
        System.out.println(">>>>>>>>>> thread end..." + Thread.currentThread().getName()
                + " is daemon: " + Thread.currentThread().isDaemon() + "," + (System.currentTimeMillis() - now.getTime()));
        /*
        结果：
        >>>>>>>>>> thread start...Test worker,Mon Aug 23 16:31:47 CST 2021
        >>>>>>>>>> thread end...Test worker is daemon: false,3
        >>>>>>>>>> testDaemonThread start...testDaemonThread
         */
    }
    /**
     * 测试非守护线程
     */
    @Test
    public void testNonDaemonThread() throws InterruptedException {
        Date now = new Date();
        System.out.println(">>>>>>>>>> thread start..." + Thread.currentThread().getName() + "," + now);
        Thread thread = new Thread(() -> {
            System.out.println(">>>>>>>>>> testNonDaemonThread start..." + Thread.currentThread().getName());
            try {
                TimeUnit.SECONDS.sleep(2L);
            } catch (InterruptedException e) {
                e.printStackTrace();
            } finally {
                System.out.println(">>>>> testNonDaemonThread finally");
            }
            System.out.println(">>>>>>>>>> testNonDaemonThread end..." + Thread.currentThread().getName());
        }, "testDaemonThread");
        thread.setDaemon(false);
        thread.start();
//        thread.join();
        System.out.println(">>>>>>>>>> thread end..." + Thread.currentThread().getName()
                + " is daemon: " + Thread.currentThread().isDaemon() + "," + (System.currentTimeMillis() - now.getTime()));
        /*
        结果：
        >>>>>>>>>> thread start...Test worker,Mon Aug 23 16:32:05 CST 2021
        >>>>>>>>>> thread end...Test worker is daemon: false,3
        >>>>>>>>>> testNonDaemonThread start...testDaemonThread
         */
    }
    public static void main(String[] args) throws InterruptedException {
        ThreadDemo demo = new ThreadDemo();
//        demo.testNonDaemonThread();
        demo.testDaemonThread();
        /*
        >>>>>>>>>> thread start...main,Mon Aug 23 16:33:43 CST 2021
        >>>>>>>>>> thread end...main is daemon: false,41
        >>>>>>>>>> testDaemonThread start...testDaemonThread
         */
    }
    @Test
    public void test() {
    }
}

2.2 案例结果

测试中发现，@Test 与 main 输出的结果不一样
testDaemonThread 方法结果：

test 的：
>>>>>>>>>> thread start...Test worker,Mon Aug 23 16:35:23 CST 2021
>>>>>>>>>> thread end...Test worker is daemon: false,2
>>>>>>>>>> testDaemonThread start...testDaemonThread
-------------------
main 的：
>>>>>>>>>> thread start...main,Mon Aug 23 16:37:04 CST 2021
>>>>>>>>>> thread end...main is daemon: false,43
>>>>>>>>>> testDaemonThread start...testDaemonThread

testNonDaemonThread 方法结果：

@Test 的
>>>>>>>>>> thread start...Test worker,Mon Aug 23 16:37:32 CST 2021
>>>>>>>>>> thread end...Test worker is daemon: false,2
>>>>>>>>>> testNonDaemonThread start...testDaemonThread
---------------
main 的：
>>>>>>>>>> thread start...main,Mon Aug 23 16:38:26 CST 2021
>>>>>>>>>> thread end...main is daemon: false,44
>>>>>>>>>> testNonDaemonThread start...testDaemonThread
>>>>> testNonDaemonThread finally
>>>>>>>>>> testNonDaemonThread end...testDaemonThread

感觉有点奇怪。