java - 将 Scanner 对象连接到 System.in 对象并使用 Scanner 方法

Question

这是我的问题:

我正在尝试使用 Scanner 和 System.in 从键盘获取输入并将其分配给 int 变量。

这就是我所拥有的(完整的程序如下):

// this program will use scanner objects and system inputs
public class Scanner
{
    public static void main(String[] args)
    {
        int number;  
             // declares integer "number"

        Scanner keyboard = new Scanner(System.in); 
  //-------------------------------------------------------------------
  // declares referance variable (Scanner class) "keyboard", creates       
  // Scanner object that 
  // reads input from System.in, then assigns address of Scanner object 
  // to the reference variable "keyboard"
  //-------------------------------------------------------------------     
        System.out.println("Enter an integer value: ");
             // displays text 
        number = keyboard.nextInt();
            // assigns keyboard input to "number" as integer value

        System.out.println("You entered the integer " + number);
           // displays "number" to see if the program worked
    }
}

当我尝试使用 javac 在 Windows 命令提示符下编译程序时，收到以下错误消息:

error: constructor Scanner in class Scanner
cannot be applied to given types;

Scanner keyboard = new Scanner(System.in);

required: no arguments
found: InputStream
reason: actual and formal argument lists differ in length

error: cannot find symbol
            number = keyboard.nextInt();
                             ^
symbol:   method nextInt()
location: variable keyboard of type Scanner
2 errors

我做错了什么？

Answer 1

存在命名冲突。从 Java 语言的角度来看，您必须使您的 Scanner 类独一无二，有 2 个选项可以做到这一点:

1. 重命名类(class)
   • 改成其他名称，这样就不会再出现命名冲突

2. 使 Scanner 类明确

   • 通过使用完全限定名称

     public static void main(String[] args)
     {
         int number;
         java.util.Scanner keyboard = new java.util.Scanner(System.in);
     
         System.out.println("Enter an integer value: ");
     
         number = keyboard.nextInt();
         System.out.println("You entered the integer " + number);
     }