Java에서 스레드를 시작하는 세 가지 방법 비교 분석

public class java_thread extends Thread{
  public static void main(String args[])
  {
    (new java_thread()).run();
    System.out.println("main thread run ");
  }
  public synchronized void run()
  {
    System.out.println("sub thread run ");
  }
  
}

public class java_thread implements Runnable{
  public static void main(String args[])
  {
    (new Thread(new java_thread())).start();
    System.out.println("main thread run ");
  }
  public void run()
  {
    System.out.println("sub thread run ");
  }
  
}

void java_thread()
{
  
   Thread t = new Thread(new Runnable(){
      public void run(){
      mSoundPoolMap.put(index, mSoundPool.load(filePath, index));
      getThis().LoadMediaComplete();
      }});
    t.start();
}