Question

这是我的主要工作正常。我试图让它运行，直到用户输入“。”然后它会说再见。我尝试了一个while循环，但它给了我一个错误。我想就如何循环它提出一些建议。我认为这是时期。我尝试了条件== true。

public class Main {

public static void main(String[] args) throws Exception 
{
    System.out.printf("Welcome to name database\n\n");
    NameHandler nameHandler = new NameHandler();
    NamePrinter namePrinter = new NamePrinter();
    SecureRandom random = new SecureRandom();
   // boolean condition = true;

    List<Name> name
        = nameHandler.findName();
    namePrinter.print(name);
    Scanner scanner = new Scanner(System.in);

    Scanner sc=new Scanner(System.in);
    String str=sc.next()

    while(!str.equals("."))
     {
    System.out.printf("\nENTER DATA FOR NEW NAME\n");
    Integer id = random.nextInt(1000);
    System.out.printf("FIRST_NAME: ");
    String fname = scanner.nextLine();
    System.out.printf("LAST_NAME: ");
    String lname = scanner.nextLine();


    Name newName = new Name();
    newName.setFname(fname);
    newName.setId(id);
    newName.setLname(lname);

    int insertCount = nameHandler.insert(newName);
    System.out.printf("%nInsert count: %d%n", insertCount);
    namePrinter.print(
        nameHandler.findName());

    System.out.printf("\nUPDATE NAME\n");
    System.out.printf("ID: ");
    id = Integer.parseInt(scanner.nextLine());
    System.out.printf("FIRST_NAME: ");
    fname = scanner.nextLine();
    System.out.printf("LAST_NAME: ");
    lname = scanner.nextLine();


    int updateCount = nameHandler.update(id, fname, lname);
    System.out.printf("%nUpdate count: %d%n", updateCount);
    namePrinter.print(
        nameHandler.findName()
    );

    System.out.printf("\nDELETE A NAME\n");
    System.out.printf("ID: ");
    id = Integer.parseInt(scanner.nextLine());

    int deleteCount = nameHandler.delete(id);
    System.out.printf("%nDelete count: %d%n", deleteCount);
    namePrinter.print(
        nameHandler.findName()
    );}

    System.out.printf("\nGood bye!\n");
  }

Answer 1

这只是您查询的示例代码：

 Scanner sc=new Scanner(System.in);
 String str=sc.next()

 while(!str.equals("."))
 {
    //code that needs to loop
 }

我怎样才能让我的java程序循环到“。”进入？

1 个答案: