java - 错误 Java 异常 java.lang.IllegalThreadStateException

Question

在 Java 中，我收到此异常:

线程“main”中的异常 java.lang.IllegalThreadStateException

这是代码:

class Worker extends Thread
{
   public void run() {
   System.out.println("#");
 }
}

class Seconda extends Thread
{
   public void run() {
       System.out.println("*");
   }
}


public class First
{
   public static void main(String args[]) {
      int contatore=0;
      Worker prova = new Worker();
      Seconda prova2 = new Seconda();
      prova.start();
      prova2.start();
      for(;;) {
               if(!prova.isAlive()) { prova.start();
                                      contatore++;
                                    } 
           if(!prova2.isAlive()) { prova2.start();
                                   contatore++;
                                 }
           if(contatore==50) System.out.println(""); 
          }

   }
 }

异常是什么意思？

Answer 1

您正在尝试启动一个已经启动的线程。

您需要做的是在 for 循环内创建 prova 和 prova2？

public static void main(String args[]) {
  int contatore=0;
  //Worker prova = new Worker();
  //Seconda prova2 = new Seconda();
  //prova.start();
  //prova2.start();
  for(;;) {
     Worker prova = new Worker();
     Seconda prova2 = new Seconda();
     if(!prova.isAlive()) { 
        prova.start();
        contatore++;
     } 
     if(!prova2.isAlive()) { 
        prova2.start();
        contatore++;
     }
     if(contatore==50) System.out.println(""); 
     }
}