我正在尝试为我的程序创建一个简单的菜单来读取用户输入.这是代码：

public void menu() {

String command;

System.out.println("To operate with words write: a");

System.out.println("To operate with products write: b");

System.out.print("

Give the command: ");

Scanner scanner = new Scanner(System.in);

command = scanner.nextLine();

if (command.equals("a")) {

System.out.println("

Good job! You have chosen the word program

");

System.out.println("You can only use the following commands: ");

System.out.println("exit - to exit the program");

System.out.println("add - to add a word into the map");

System.out.println("lookup - to lookup a word into the map

");

System.out.print("Give a command: ");

command = scanner.next();

while(scanner.hasNext()){

command = scanner.next();

if(command.equals("add")){

this.addWord();

}

System.out.print("Give a command: ");

command = scanner.next(); //Here I get the ERROR that throws Exception

}

}

scanner.close();

}

public static void main(String [] args)

{

HashTableInterface table = new HashTable();

Dictionary d = new Dictionary(table);

RepositoryInterface repo = new Repository(d);

ControllerInterface controller = new Controller(repo);

Console c = new Console(controller);

c.menu()

}

这是我得到的例外测试：

To operate with words write: a

To operate with products write: b

Give the command: a

Good job! You have chosen the word program

You can only use the following commands:

exit - to exit the program

add - to add a word into the map

lookup - to lookup a word into the map

Give a command: add

add

Give the word: mar

Give the word's plural: mere

The hash code for mar is: 3

Give a command: Exception in thread "main" java.util.NoSuchElementException

at java.util.Scanner.throwFor(Scanner.java:907)

at java.util.Scanner.next(Scanner.java:1416)

at console.Console.menu(Console.java:56)

at test.Prog.main(Prog.java:26)

我从while循环中删除了第二个命令= Scanner.next(),但是让我仅读取一次用户输入.怎么解决呢？

更新：AddWord方法：

public void addWord() {

Scanner scanner = new Scanner(new InputStreamReader(System.in));

System.out.print("Give the word: ");

String word = scanner.nextLine();

System.out.print("Give the word's plural: ");

String plural = scanner.nextLine();

scanner.close();

controller.addTheWord(word, plural);

}