如何从一个提示符中接收Java中的两种类型的输入

Question

我是一名初学Java程序员，我正在编写一个方法，该方法接受一个名为id的整数值，并根据存储在链表中的对象中的整数值进行检查。这意味着它需要整数输入。但是，我还希望用户在提示符下键入x并使方法停止并返回到程序主菜单。问题是虽然我不知道如何从一个输入中做到这一点。这是我目前的代码，尽我所能。如果您需要程序的其余部分来帮助我添加它。我只是把事情做得很少，以帮助发现问题。

我在运行时也会遇到问题。即使输入现有Id，它也不会返回正数。此外，我当前的实现意味着用户必须输入两次，一次满足while条件，另一次实际搜索链表。我相信有更好的方法，但是我的知识还没有延伸到那么远。

以下是提示用户输入将在链接列表中搜索匹配项的整数的方法，它是Client类的一部分。任何帮助表示赞赏。

public void getClient() {
      System.out.println("Please enter client Id");  
        char choice;
        int searchid = In.nextInt();
        boolean exists = false;

      while ((choice = In.nextChar()) !='x' ){
        for (Person i:clients)
            if  (i.getId() == searchid){
                 exists = true;
                 System.out.println("found client");
        }

        if (exists == false)
            System.out.println("No such client");

       }

    }

这是管理输入的类

import java.util.*;

public class In
{   private static Scanner in = new Scanner(System.in);

public static String nextLine()
    {   return in.nextLine(); }

 public static char nextChar()
    {   return in.nextLine().charAt(0); }

    public static int nextInt()
    {   int i = in.nextInt();
        in.nextLine();
        return i;   }
}

如果有帮助，这里是Client类

import java.io.*;
import java.util.*;

public class Clients implements Serializable
{   private LinkedList<Person> clients = new LinkedList<Person>();
    private int id = 1;

    public Clients()
    {   clients.add(new Person("Ben", id++));
        clients.add(new Person("Jerry", id++));  

    }

    public  void makePerson(){

        clients.add(createPerson());

    }

    public void removeClient() {

        String searchname = readName();
        boolean removed = false;

        for (Person i:clients)
            if  (i.matches(searchname)){
                clients.remove(i); 
                removed = true;
        }

        if (removed == false)
            System.out.println("  No such client");

    }

    public void getClient() {
      System.out.println("Please enter client Id");  
        char choice;
        int searchid = In.nextLine();
        Integer.parseInt(choice);
        boolean exists = false;

      while ((choice = In.nextChar()) !='x' ){
        for (Person i:clients)
            if  (i.getId() == searchid){
                 exists = true;
                 System.out.println("found client");
        }

        if (exists == false)
            System.out.println("  No such client");

       }

    }


    public  Person createPerson()
    {
        String name = readName();

        Person p = new Person(name, id++);
        System.out.println("  Hi " + p.getName() + ", " + "you are Car Owner" + p.getId());
        return p;

    }

    private  String readName() {
        System.out.print("  Name: ");
        return In.nextLine();
    }

    public void showClients() {

        for (Person i: clients)
            System.out.println(i);

    }

}

这里也是Person类

import java.io.*;
import java.text.*;

public class Person implements Serializable
{   private String name;
    private int id;
    private double cash = 100.00;
    private int start = 0;
    private int end = 0;
    private double charge = 0;

    public Person(String name, int id)
    {   this.name = name;
        this.id = id + 100; }

    public boolean uses(int stop)
    {   return getsOn(stop) || getsOff(stop); }

    public boolean getsOn(int stop)
    {   return start == stop;  }

    public boolean getsOff(int stop)
    {   return end == stop;  }

    public String handle()
    {   return name + id;   }

    public double readCash() {

        return this.cash;

    }

    public int getId() {
    return this.id;

}

public String getName() {

    return this.name;

}

@Override
public String toString() {
    String result = "  " + this.name + " (Scuba" + this.id + ") has "  + formatted(this.cash); 
    return result;
}

private String formatted(double amount)
{   DecimalFormat twoD = new DecimalFormat("$###,##0.00");
    return twoD.format(amount);  }

public boolean matches(String name)
{ return this.name.equals(name) || name.equals(this.name + this.id); }

}