Java - 僅包含字符串的重載構造函數的問題

Question

我無法弄清楚如何正確地向用戶詢問 3 個表示屬性的輸入，這些屬性將用於創建將打印在屏幕上的對象，並確保輸入不是錯誤的值。 例如，如果用戶輸入 0.5 作為直徑，它將更改為 1。重載構造函數應該表示一個文件的名稱，該文件將包含正在創建的對象的名稱、直徑和溫度。

當我嘗試運行它時，會出現缺少符號的錯誤。 我怎樣才能得到它，以便將字符串作為其唯一參數的重載構造函數被調用到 Object2 類中以創建對象？

public class Object1
{
   //attributes
   private double yyy;
   private int zzz;
   private String xxx;
   private String fileName;

   //symbolic constants
   private final double MINDIAMETER = 1;
   private final int MINTEMP = 300;
   private final String NA = "N/A";

   // getter/setter methods for name
   public void setName(String n)
   {
   if (n != "")
   xxx = n;

   else 
   xxx = NA;
   }

   public String getName()
   {
   return xxx;
   }

   // getter/setter methods for diameter
   public void setDiameter(double d)
   {
   if (d >= MINDIAMETER)
   yyy = d;

   else 
   yyy = MINDIAMETER;
   }

   public double getDiameter()
   {
   return yyy;
   }

   // getter/setter methods for temperature
   public void setTemp(int t)
   {
   if (t >= MINTEMP)
   zzz = t;

   else 
   zzz = MINTEMP;
   }

   public int getTemp()
   {
   return zzz;
   }

   public Object1()
   {
      xxx = NA;
      yyy = MINDIAMETER;
      zzz = MINTEMP;
   }

   public Object1(String n, double d, int t)
   {
      setName(n);
      setDiameter(d);
      setTemp(t);
   }

   public Object1(String f)
   {
        fileName = f; //Initialize the object's fileName with f
        System.out.print("Enter the filename: ");


   }

   public String toString()
   {
      return "A object, named " + xxx + ", with a diameter of " + yyy + " miles, and a temperature of " + zzz + " Kelvin.";
   }
}

單獨的文件代碼

import java.util.Scanner;
import java.io.FileWriter;
import java.io.File;
import java.io.PrintWriter;
import java.io.FileReader;
import java.io.IOException;

public class Object2
{
   public static void main(String[] args) throws IOException
   {

         // object with overload
        Object1 z;
        z = new Object1("");

        Scanner kb = new Scanner(System.in);


        fileName = kb.nextLine();
        File file = new File(fileName);
        PrintWriter outputFile = new PrintWriter(file);

        System.out.println("please enter name: ");
        while (kb.hasNext())
        {

        name = kb.nextLine();
        System.out.println("please enter the diameter: ");
        diameter = kb.nextDouble();
        System.out.println("please enter the temperature: ");
        temp = kb.nextInt();

        System.out.println(name + " " + diameter + " " + temp);

        outputFile.println(name);
        outputFile.println(diameter);
        outputFile.println(temp);
        }


        outputFile.close();
        System.out.println(z);
    }
}

Answer 1

首先，您的 Object1 類中必須進行一些更改。

public class Object1
{
   ...

   public void setName(String n)
   {
   if (!n.equals(""))
   xxx = n;

   else 
   xxx = NA;
   }

   ...
}

其次，您需要將掃描儀值實現到您的對象。

z.setName(kb.nextLine());
System.out.println("please enter the diameter: ");
z.setDiameter(kb.nextDouble());
System.out.println("please enter the temperature: ");
z.setTemp(kb.nextInt());

System.out.println(z.getName + " " + z.getDiameter + " " + z.getTemp);

outputFile.println(z.getName);
outputFile.println(z.getDiameter);
outputFile.println(z.getTemp);