import java.util.*;

class Ss
{
    int id, salary;
    String name;

   void Ss(int id, int salary, String name)
    {
        this.id = id;
        this.salary = salary;
        this.name = name;
    }

    void display()
    {
        System.out.println("The id of employee:" + id);
        System.out.println("The name of employye:" + name);
        System.out.println("The salary of employee:" + salary);
    }
}

class employee
{
    public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);

        Ss s = new Ss(sc.nextInt(), sc.nextInt(), sc.nextLine());
        s.display();
    }
}

说明java.util.Scanner如何工作的一个简单示例是从System.in中读取单个整数。这真的很简单。

Scanner sc = new Scanner(System.in);
int i = sc.nextInt();

要检索用户名，我可能会使用sc.nextLine()。

System.out.println("Enter your username: ");
Scanner scanner = new Scanner(System.in);
String username = scanner.nextLine();
System.out.println("Your username is " + username);

如果您想对输入进行更多控制，或者只是验证用户名变量，也可以使用next(字符串模式)。

你可以在java.util.Scanner的API文档中找到更多关于它们实现的信息

有一种从控制台读取的简单方法。

请查看以下代码:

import java.util.Scanner;

    public class ScannerDemo {

        public static void main(String[] args) {
            Scanner sc = new Scanner(System.in);

            // Reading of Integer
            int number = sc.nextInt();

            // Reading of String
            String str = sc.next();
        }
    }

具体理解请参考以下文件。

Doc

现在我们来详细了解一下Scanner类的工作原理:

public Scanner(InputStream source) {
    this(new InputStreamReader(source), WHITESPACE_PATTERN);
}

这是用于创建Scanner实例的构造函数。

这里我们传递的是InputStream引用，它只是一个System.In。在这里，它打开了用于控制台输入的InputStream管道。

public InputStreamReader(InputStream in) {
    super(in);
    try {
        sd = StreamDecoder.forInputStreamReader(in, this, (String)null); // ## Check lock object
    }
    catch (UnsupportedEncodingException e) {
        // The default encoding should always be available
        throw new Error(e);
    }
}

通过系统。在这段代码中，将打开套接字以从控制台读取。

下面是执行所需操作的完整类:

import java.util.Scanner;

public class App {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        final int valid = 6;

        Scanner one = new Scanner(System.in);
        System.out.println("Enter your username: ");
        String s = one.nextLine();

        if (s.length() < valid) {
            System.out.println("Enter a valid username");
            System.out.println(
                "User name must contain " + valid + " characters");
            System.out.println("Enter again: ");
            s = one.nextLine();
        }

        System.out.println("Username accepted: " + s);

        Scanner two = new Scanner(System.in);
        System.out.println("Enter your age: ");
        int a = two.nextInt();
        System.out.println("Age accepted: " + a);

        Scanner three = new Scanner(System.in);
        System.out.println("Enter your sex: ");
        String sex = three.nextLine();
        System.out.println("Sex accepted: " + sex);
    }
}

Scanner scan = new Scanner(System.in);
String myLine = scan.nextLine();

import java.util.Scanner;  // Import the Scanner class

class Main { // Main is the class name
  public static void main(String[] args) {
    Scanner myObj = new Scanner(System.in);  // Create a Scanner object
    System.out.println("Enter username");

    String userName = myObj.nextLine();  // Read user input
    System.out.println("Username is: " + userName);  // Output user input
  }
}