main方法里面写了个线程start，结果每次都是main的先顺序执行完成？

package com.thread.simple;

public class ThreadOne extends Thread {

    @Override
    public void run() {
        for (int i = 0; i < 10; i ++) {
            System.out.println("sub" + i);
        }
    }

    public static void main(String[] args) throws InterruptedException {
        Thread thread = new ThreadOne();
        thread.start();
        for (int i = 0; i < 10; i ++) {
            System.out.println("main－－" + i);
//            Thread.sleep((int) (Math.random() * 1000));
        }


    }
}