System.out.println(1);
		Thread thread=new Thread(new Runnable() {
			public void run() {
				System.out.println(2);
			}
		});
		thread.start();
		System.out.println(3);

結果打印出來是

1,3,2.我就糾結了，我只想他列印完2之後再執行列印3，怎麼辦

		System.out.println(1);
		Thread thread=new Thread(new Runnable() {
			public void run() {
				System.out.println(2);
			}
		});
		thread.start();
		try {
			//等待執行緒執行完
			thread.join();
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		System.out.println(3);
	
 

thread.join();