2 different ways to create thread Java

Topic details:

7-1 2 Different Ways to Create Threads (25 points)

######There are two ways to create a thread. One is to inherit Thread to create a subclass, such as:

class sub_Thread extends Thread{
…
public void run() { //重写  run
      …
}
}
Thread th = new sub_Thread (….);// 创建线程对象

Another implementation of Runnable, ######1. Create the target object class: implement the Runnable interface class

class target implements Runnable{
//实现Runnable接口 ，线程启动 执行run方法，可以共享 类里面的成员变量
   public void run() { //重写
  …..
}
}

2. Create a Thread thread object, the constructor Thread(Runnable target)
Thread th = new Thread(target);// Create a thread object

The programming implementation creates two threads, and the requirements are as follows: (1) One thread outputs the sum of 1 to n, and the other thread outputs the factorial of 1 to n. (2) One thread uses the writing method of the Thread subclass, and the other thread uses the writing method that implements the Runnable interface. There is an attribute int n in the thread class, there is a parameter construction method to assign value to n, and the run method is rewritten to realize the calculation and output the result  ###### It is required to write a complete program to  define the thread class

The main class prompt is as follows:

public class Main {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        int choice=sc.nextInt();
        Thread th1=new math_thread(n);
        target_thread  tar=new target_thread(n);
        Thread th2=new Thread(tar);
        switch(choice) {
        case 1:th1.start();break;
        case 2:th2.start();break;
        }
    }
}

Input format:

Enter the value of n on line 1######Enter 1 or 2 on line 2

Output format:

If the input in the second line of the input format is 1, output the value of the summation ######If the input in the second line of the input format is 2, output the value of the factorial

Input sample:

A set of inputs is given here. E.g:

5
1

no blank line at the end

Sample output:

The corresponding output is given here. E.g:

15

no blank line at the end

Answer code:

import java.util.Scanner;
public class Main {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        int choice=sc.nextInt();
        Thread th1=new math_thread(n);
        target th2=new target(n);
        Thread th = new Thread(th2);
        switch(choice) {
            case 1:th1.start();break;
            case 2:th.start();break;
        }
    }
}
class math_thread extends Thread{
        int n;

    public math_thread(int n) {
        this.n = n;
    }

    @Override
    public void run() {
        int sum=0;
        for(int i = 1;i<=n;i++){
            sum+=i;
        }
        System.out.println(sum);
    }
}
class target implements Runnable{
    int n;

    public target(int n) {
        this.n = n;
    }
    @Override
    public void run() {
        int sum=1;
        for(int i=1;i<=n;i++){
            sum=sum*i;
        }
        System.out.println(sum);
    }
}