最简单的方法之一是使用扫描仪对象如下：

One of the simplest ways is to use a Scanner object as follows:

import java.util.Scanner;

Scanner reader = new Scanner(System.in);  // Reading from System.in
System.out.println("Enter a number: ");
int n = reader.nextInt(); // Scans the next token of the input as an int.
//once finished
reader.close();