将扫描器对象连接到System.In对象并使用扫描器方法

Question

// 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命令提示符中编译程序时，我得到以下错误消息：

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

有一个命名冲突。从Java语言的角度来看，您必须使scanner类唯一，有两个选项可以做到这一点：

• 重命名类
  • 改为其他名称，以便不再发生命名冲突

  使scanner类明确

  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);
  }