java实例化内部类方式

实例化内部类必须先实例化外部类，然后把内部类当做成员变量来实例化

public class TestThread {
	
	public static void main(String[] args) {
		TestThread t = new TestThread(); //先实例化外部类，把内部类当做成员变量实例化
		Thread t1 = t.new PrintThread(1);//实例化内部类方式
		Thread t2 = t.new PrintThread(2);
		t1.start();
		t2.start();
		
	}
	class PrintThread extends Thread{
		private int threadNum;
		public PrintThread(int threadNum) {
			this.threadNum = threadNum;
		}
		public PrintThread() {
		}
		public void run() {
			for (int i = 0; i < 5; i++) {
				System.out.println("线程"+threadNum+"正在运行");
			}
			
		}
	}