不,你不能直接调用run方法来启动一个线程。您需要调用 start 方法来创建一个新线程。 如果你直接调用run方法,它不会创建一个新线程,它会和main在同一个栈中。 让我们在示例的帮助下理解:
package org.arpit.java2blog; class CustomThread extends Thread { public void run() { for (int i = 0; i < 5; i++) { try { Thread.sleep(300); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println("Thread is running :"+i); } } } public class StartThreadAgainMain { public static void main(String[] args) { CustomThread ct1 = new CustomThread(); CustomThread ct2 = new CustomThread(); ct1.run(); ct2.run(); } }
当您运行上面的程序时,您将得到以下输出:
Thread is running :0 Thread is running :1 Thread is running :2 Thread is running :3 Thread is running :4 Thread is running :0 Thread is running :1 Thread is running :2 Thread is running :3 Thread is running :4
正如您所看到的,当我们直接调用 run 方法时,它并没有创建新线程。
如果您在上面的示例中使用 start 而不是 run:
package org.arpit.java2blog; class CustomThread extends Thread { public void run() { for (int i = 0; i < 5; i++) { try { Thread.sleep(300); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println("Thread is running :"+i); } } } public class StartThreadAgainMain { public static void main(String[] args) { CustomThread ct1 = new CustomThread(); CustomThread ct2 = new CustomThread(); ct1.start(); ct2.start(); } }
Thread is running :0 Thread is running :0 Thread is running :1 Thread is running :1 Thread is running :2 Thread is running :2 Thread is running :3 Thread is running :3 Thread is running :4 Thread is running :4
不能直接调用run方法创建线程,需要调用start方法创建新线程。
原文链接:https://codingdict.com/