심볼을 찾을 수 없습니다 : Thread.sleep (1000);

Question

Runnable 인터페이스를 사용하여 스레드를 구현하고 싶습니다.

내가 가지고있는 다음과 같은 세 가지 클래스 :

FirstThread.java

public class FirstThread implements Runnable 
{ 

    //This method will be executed when this thread is executed 
    public void run()  
    {     

    //Looping from 1 to 10 to display numbers from 1 to 10  
    for (int i=1; i<=10; i++)  
    {   
     //Displaying the numbers from this thread   
     System.out.println("Messag from First Thread : " +i);      

     /*taking a delay of one second before displaying next number    
     *    
     * "Thread.sleep(1000);" - when this statement is executed,   
     * this thread will sleep for 1000 milliseconds (1 second)   
     * before executing the next statement.   
     *    
     * Since we are making this thread to sleep for one second,   
     * we need to handle "InterruptedException". Our thread   
     * may throw this exception if it is interrupted while it    
     * is sleeping.   
     *    
     */   
     try    
     {    
      Thread.sleep (1000);    
     }   
     catch (InterruptedException interruptedException)   
     {    
      /*Interrupted exception will be thrown when a sleeping or waiting 
      *thread is interrupted.     
      */    
      System.out.println("First Thread is interrupted when it is sleeping" +interruptedException);   
     } 
    } 
    } 
} 

SecondThread.java :

public class SecondThread implements Runnable 
{ 

    //This method will be executed when this thread is executed 
    public void run() 
    {   

     //Looping from 1 to 10 to display numbers from 1 to 10  
     for (int i=1; i<=10; i++)   
     {    
     System.out.println("Messag from Second Thread : " +i);      

     /*taking a delay of one second before displaying next number    
     *   
     * "Thread.sleep(1000);" - when this statement is executed,    
     * this thread will sleep for 1000 milliseconds (1 second)   
     * before executing the next statement.    
     *   
     * Since we are making this thread to sleep for one second,    
     * we need to handle "InterruptedException". Our thread    
     * may throw this exception if it is interrupted while it    
     * is sleeping.    
     */    
     try   
     {    
      Thread.sleep(1000);   
     }   
     catch (InterruptedException interruptedException)   
     {    
      /*Interrupted exception will be thrown when a sleeping or waiting     
      * thread is interrupted.     
      */     
      System.out.println("Second Thread is interrupted when it is sleeping" +interruptedException);    
     }  
     }  
    } 
} 

ThreadDemo.java :

public class ThreadDemo 
{ 
    public static void main(String args[]) 
    { 
     //Creating an object of the first thread 
     FirstThread firstThread = new FirstThread(); 

     //Creating an object of the Second thread 
     SecondThread secondThread = new SecondThread(); 

     //Starting the first thread 
     Thread thread1 = new Thread(firstThread); 
     thread1.start(); 

     //Starting the second thread 
     Thread thread2 = new Thread(secondThread); 
     thread2.start(); 
    } 
} 

위의 컴파일에 홍보

FirstThread

shahjahan@shahjahan-AOD270:~/Documents/java$ javac FirstThread.java 
FirstThread.java:28: error: cannot find symbol 
      Thread.sleep (1000);    
       ^
    symbol: method sleep(int) 
    location: class Thread 
1 error 

SecondThread :

shahjahan@shahjahan-AOD270:~/Documents/java$ javac SecondThread.java 
    SecondThread.java:26: error: cannot find symbol 
       Thread.sleep(1000);   
        ^
     symbol: method sleep(int) 
     location: class Thread 
    1 error 

ThreadDemo :

shahjahan@shahjahan-AOD270:~/Documents/java$ javac ThreadDemo.java 
ThreadDemo.java:12: error: constructor Thread in class Thread cannot be applied to given types; 
     Thread thread1 = new Thread(firstThread); 
         ^
    required: no arguments 
    found: FirstThread 
    reason: actual and formal argument lists differ in length 
ThreadDemo.java:13: error: cannot find symbol 
     thread1.start(); 
      ^
    symbol: method start() 
    location: variable thread1 of type Thread 
ThreadDemo.java:16: error: constructor Thread in class Thread cannot be applied to given types; 
     Thread thread2 = new Thread(secondThread); 
         ^
    required: no arguments 
    found: SecondThread 
    reason: actual and formal argument lists differ in length 
ThreadDemo.java:17: error: cannot find symbol 
     thread2.start(); 
      ^
    symbol: method start() 
    location: variable thread2 of type Thread 
./FirstThread.java:28: error: cannot find symbol 
      Thread.sleep (1000);    
       ^
    symbol: method sleep(int) 
    location: class Thread 
./SecondThread.java:26: error: cannot find symbol 
      Thread.sleep(1000);   
       ^
    symbol: method sleep(int) 
    location: class Thread 
6 errors 

내가 자바 초보자입니다 프로그램 RL FR RR FL, 나는 다음과 같은 오류를 얻었다. thread.sleep이 작동하지 않는 이유는 무엇입니까? 스레드 구현은 컴파일되는 머신에 달려 있습니까?

Answer 1

이름이 Thread 인 일부 클래스를 가져 오거나 java.lang.Thread이 아니거나 현재 코드 디렉토리에 Thread이라는 클래스가있어 클래스에 대한 가져 오기를 오염시키고 있습니다.

제거/귀하의 폴더에 '스레드'라는 어떤 클래스의 이름을 변경하고 코드에 문제가 없습니다 Thread

Answer 2

라는 클래스에 대한 모든 수입을 제거, 나는 그것을 테스트하고 그것을 잘 일하고있어.

프로젝트에서 Thread라는 클래스가 있으면 제거하거나 이름을 바꾸고 다시 시도하십시오. 충돌하는 Thread 클래스가있을 수 있습니다.