public static void main(String[] args) {
		final Scanner sc=new Scanner(System.in);
		Thread th1=new Thread(new Runnable(){
			private Scanner sct=sc;
			public void run(){
				try {
					String s="a";
					while(! s.equals("")){
						System.out.println("escribe: ");
						s=sct.nextLine();
						System.out.println(s);
					}
				} catch (Exception e) {
					// TODO Auto-generated catch block
				}
			}
		});
		th1.start();
		
		try {
			System.out.println("duermo para dar tiempo al hilo hijo a hacer el"
					+ "sc.nextLine()");
			Thread.currentThread().sleep(2000);
			//terminar ejecución del hilo B !!!¿¿¿Como?????¡¡¡¡
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}