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以前的输入被新输入覆盖

2016-11-22 41 views
0

嗨我真的需要我的程序帮助，我已经搜索了高和低的解决方案，但似乎无法找到我在找什么。以前的输入被新输入覆盖

我正在制作一个程序，用户添加一个桌面，为其输入各种信息，然后将其添加到数组列表中。

下面的代码：

简介：

Scanner scan = new Scanner(System.in); 
    String input; 
    boolean looper = true; 
    DecimalFormat f = new DecimalFormat("#.00"); 
    ArrayList<Desktop> desktopList = new ArrayList<>(); 
    ArrayList<Laptop> laptopList = new ArrayList<>(); 

    while (looper) { 
     System.out.println(""); 
     System.out.println("******************* Artificial Intelligence Co. *************************"); 
     System.out.println("1. Add Information for new Desktop"); 
     System.out.println("2. Add Information for new Laptop"); 
     System.out.println("3. Display all computer information"); 
     System.out.println("4. Quit"); 
     System.out.println("5. Credits"); 
     System.out.println("*************************************************************************");

switch语句和案例1：

switch (input) { 
      case "1": 
       System.out.println(""); 
       System.out.println("========================================================================="); 
       System.out.println("Information for new Desktop"); 
       System.out.println("========================================================================="); 

       Desktop xx = new Desktop(); 
       boolean loop = true; 


       while (loop) { 
        System.out.print("What is the Computer ID: "); 
        xx.setComputerID(scan.nextLine().toUpperCase()); 

        if ((xx.getComputerID().startsWith("D")) && (xx.getComputerID().length() == 4)) { 
         loop = false; 
        } else { 
         System.out.println("Computer ID should start with a letter \"D\". and have 4 characters."); 
         System.out.println(""); 
        } 
       } 

       loop = true; 
       while (loop) { 
        System.out.print("What is the Processor Speed: "); 
        xx.setCPUspeed(scan.nextLine().toUpperCase()); 
        try { 
         if (StringisDouble(xx.getCPUspeed().substring(0, (xx.getCPUspeed().length() - 2))) || 
           StringisDouble(xx.getCPUspeed().substring(0, (xx.getCPUspeed().length() - 3)))) { //checks the value before GHZ or HZ if its a double 
          if (xx.getCPUspeed().endsWith("GHZ") || xx.getCPUspeed().endsWith("HZ")) { 
           loop = false; 
          } else { 
           System.out.println("CPU Speed input should end with \"GHZ\" or \"HZ\"."); 
           System.out.println(""); 
          } 
         } else { 
          System.out.println("CPU Speed input should contain a decimal or number followed by a \"GHZ\" or a \"HZ\"."); 
          System.out.println(""); 
         } 
        } catch (StringIndexOutOfBoundsException e) { 
         System.out.println("CPU Speed input should contain a decimal or number followed by a \"GHZ\" or a \"HZ\"."); 
         System.out.println(""); 
        } 

       } 

       loop = true; 
       while (loop) { 
        System.out.print("What is the RAM: "); 
        xx.setRAM(scan.nextLine().toUpperCase()); 
        try { 
         if (StringisInteger(xx.getRAM().substring(0, (xx.getRAM().length() - 2)))) {  //checks the value if it is numeric and ending with GB or MB 
          if (xx.getRAM().endsWith("GB") || xx.getRAM().endsWith("MB")) { 
           loop = false; 
          } else { 
           System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\"."); 
           System.out.println(""); 
          } 
         } else { 
          System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\"."); 
          System.out.println(""); 
         } 
        } catch (StringIndexOutOfBoundsException e) { 
         System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\"."); 
         System.out.println(""); 
        } 


       } 

       loop = true; 
       while (loop) { 
        System.out.print("What is the Harddisk size: "); 
        xx.setHarddisk(scan.nextLine().toUpperCase()); 
        try { 
         if (StringisInteger(xx.getHarddisk().substring(0, (xx.getHarddisk().length() - 2)))) {  //checks the value if it is numeric and ending with GB or MB 
          if (xx.getHarddisk().endsWith("GB") || xx.getHarddisk().endsWith("TB")) { 
           loop = false; 
          } else { 
           System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\"."); 
           System.out.println(""); 
          } 
         } else { 
          System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\"."); 
          System.out.println(""); 
         } 
        } catch (StringIndexOutOfBoundsException e) { 
         System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\"."); 
         System.out.println(""); 
        } 
       } 


       loop = true; 
       while (loop) { 
        System.out.print("What is the Monitor: "); 
        xx.setMonitor(scan.nextLine().toUpperCase()); 
        if (xx.getMonitor().equals("CRT") || xx.getMonitor().equals("LCD")) { 
         loop = false; 
        } else { 
         System.out.println("Please enter in CRT or LCD only."); 
         System.out.println(""); 
        } 
       } 

       loop = true; 
       while (loop) { 
        try { 
         System.out.print("What is the price: $"); 
         xx.setPrice(Double.parseDouble(scan.nextLine())); 
         loop = false; 
        } catch (NumberFormatException e) { 
         System.out.println("Price input should be numeric."); 
         System.out.println(""); 
        } 
       } 

       desktopList.add(xx); 

       System.out.println("Information successfully added."); 
       System.out.println(""); 
       System.out.println(""); 
       break;

案例3，在用户获取看到他/她进入什么：

   case "3": 
       int DesktopCounter = 1; 
       int LaptopCounter = 1; 

       System.out.println(""); 
       if (desktopList.isEmpty()) { 
        System.out.println("No desktop added!"); 
        System.out.println(""); 
       } else { 
        for (int i = 0; i < desktopList.size(); i++) { 
         System.out.println(""); 
         System.out.println("Desktop " + DesktopCounter); 
         System.out.println("Computer ID: " + desktopList.get(i).getComputerID()); 
         System.out.println("Processor Speed: " + desktopList.get(i).getCPUspeed()); 
         System.out.println("RAM: " + desktopList.get(i).getRAM()); 
         System.out.println("Harddisk:" + desktopList.get(i).getHarddisk()); 
         System.out.println("Monitor: " + desktopList.get(i).getMonitor()); 
         System.out.println("Price: $" + f.format(desktopList.get(i).getPrice())); 
         DesktopCounter++; 
        } 
       } 
       break;

桌面级：

 public class Desktop extends Computer //Child class of Computer 
    { 
     private static String Monitor; 

     public Desktop() 
     { 
      ComputerID = "-- No ID specified --"; 
      CPUspeed = "-- No processor speed specified --"; 
      RAM = "-- No RAM specified-"; 
      Harddisk = "-- No Harddisk size specified --"; 
      Monitor = "-- No Monitor specified --"; 
      Price = 0.0; 
     } 



//Setters and Getters 
    public String getMonitor() 
    { 
     return Monitor; 
    } 

    public void setMonitor(String monitor) 
    { 
     Monitor = monitor; 
    } 


}

计算机类：

  • 计算机ID：

    public class Computer //Parent class 

{ 
protected static String ComputerID; 
protected static String CPUspeed; 
protected static String RAM; 
protected static String Harddisk; 
protected static double Price; 


public Computer() //Initializer 
{ 
    ComputerID = "-- No ID specified --"; 
    CPUspeed = "-- No processor speed specified --"; 
    RAM = "-- No amount RAM specified-"; 
    Harddisk = "-- No Harddisk size specified --"; 
    Price = 0.0; 
} 

public Computer(String computerID, String cpuspeed, String ram, String harddisk, double price) { 
    ComputerID = computerID; 
    CPUspeed = cpuspeed; 
    RAM = ram; 
    Harddisk = harddisk; 
    Price = price; 


} 


//Getters and Setters 
public String getComputerID() { 
    return ComputerID; 
} 

public void setComputerID(String computerID) { 
    ComputerID = computerID; 
} 

public String getCPUspeed() { 
    return CPUspeed; 
} 

public void setCPUspeed(String cpuspeed) { 
    CPUspeed = cpuspeed; 
} 

public String getRAM() { 
    return RAM; 
} 

public void setRAM(String ram) { 
    RAM = ram; 
} 

public String getHarddisk() { 
    return Harddisk; 
} 

public void setHarddisk(String harddisk) { 
    Harddisk = harddisk; 
} 

public double getPrice() { 
    return Price; 
} 

public void setPrice(double price) { 
    Price = price; 
} 

//End of getters and setters

    }

    现在说，如果我添加使用情况1以下信息桌面中输入：D001

  • 处理器速度：3.2GHZ
  • RAM：512MB
  • 硬盘：80GB
  • 显示器：CRT

，然后继续添加其他桌面这些：

  • 计算机ID：D123
  • 处理器速度： 4.4GHZ
  • RAM：8GB
  • 硬盘： 1TB
  • 显示器：LCD

当我显示使用外壳3码块中的信息时，其输出：

  • 桌面1
  • 计算机ID：D123
  • 处理器速度：4 。4GHZ
  • 内存：8GB
  • 硬盘：1TB
  • 显示器：液晶


  • 桌面2
  • 计算机ID：D123
  • 处理器速度：4.4GHZ
  • RAM：8GB
  • 硬盘：1TB
  • 显示器：液晶

当权，桌面1应该显示自己的独特属性。

我将不胜感激任何帮助。

编辑：我通过让我的变量非静态来解决这个问题。经过额外的代码

来源

2016-11-22 Zee Jay

+0

你可以把完整的代码，而不是代码片段，这样很容易找到变量/引用正在初始化和循环打破。 –

回答

0

更新被张贴

你的领域不应该是静态在Desktop，Computer和Laptop类。更改这些字段：

protected static String ComputerID; 
protected static String CPUspeed; 
protected static String RAM; 
protected static String Harddisk; 
protected static double Price;

到

protected String ComputerID; 
protected String CPUspeed; 
protected String RAM; 
protected String Harddisk; 
protected double Price;

静态字段是一类的每个对象相同。因此，如果您有多个桌面，并且您声明价格静态，则所有桌面将共享相同的价格字段。这不是你想要的，显然所有的台式机都有另一个价格。

而且改变

private static String Monitor;

到

private String Monitor;

你真的想拥有计算机每一个单独的显示器，而不是共享同一个显示器的所有计算机。

老答案

代码运行完全在这里，所以一定是有缺失的信息：这个问题必须在代码的某些部分，你没有张贴：

******************* Artificial Intelligence Co. ************************* 
1. Add Information for new Desktop 
2. Add Information for new Laptop 
3. Display all computer information 
4. Quit 
5. Credits 
************************************************************************* 
3 

Desktop 1 
Computer ID: D123 
Processor Speed: 2GHZ 
RAM: 2GB 
Harddisk:1TB 
Monitor: CRT 
Price: $100.00 

Desktop 2 
Computer ID: D002 
Processor Speed: 2GHZ 
RAM: 16GB 
Harddisk:2TB 
Monitor: CRT 
Price: $500.00

的几点思考：

  • 你没有贴Desktop类，如果Desktop类中的字段声明为static c，这将解释结果，确保它们没有被声明为静态的
  • 它看起来像你在某处使用相同的变量，例如，Desktop xx = new Desktop();不在case语句如在上述
  • 你可能使用了错误的索引来获取列表中的项目的代码，你是一个对-i循环的循环，做desktopList.get(i)如果你碰巧做desktopList.get(0)或desktopList.get(someVariableThatIsAlwaysZero)您将始终打印相同的结果。使用新的foreach语法更安全：for (Desktop desktop : desktopList){ ... }
  • 您必须学会使用调试器，逐步浏览代码并查看插入重复值的位置，并且如果没有插入重复值，请参阅打印位置语句正在打印以及为什么它们打印相同的值;使用调试器是非常重要的发现问题
  • 你的代码可能是不同步的

我只是给你我的版本的作品，所以你可能想比较：

public static void main(String args[]) { 

     Scanner scan = new Scanner(System.in); 
     String input; 
     boolean looper = true; 
     DecimalFormat f = new DecimalFormat("#.00"); 
     ArrayList<Desktop> desktopList = new ArrayList<>(); 
     ArrayList<Laptop> laptopList = new ArrayList<>(); 

     while (looper) { 
      System.out.println(""); 
      System.out.println("******************* Artificial Intelligence Co. *************************"); 
      System.out.println("1. Add Information for new Desktop"); 
      System.out.println("2. Add Information for new Laptop"); 
      System.out.println("3. Display all computer information"); 
      System.out.println("4. Quit"); 
      System.out.println("5. Credits"); 
      System.out.println("*************************************************************************"); 

      input = scan.nextLine(); 

      switch (input) { 
       case "1": 
        System.out.println(""); 
        System.out.println("========================================================================="); 
        System.out.println("Information for new Desktop"); 
        System.out.println("========================================================================="); 

        Desktop xx = new Desktop(); 
        boolean loop = true; 


        while (loop) { 
         System.out.print("What is the Computer ID: "); 
         xx.setComputerID(scan.nextLine().toUpperCase()); 

         if ((xx.getComputerID().startsWith("D")) && (xx.getComputerID().length() == 4)) { 
          loop = false; 
         } else { 
          System.out.println("Computer ID should start with a letter \"D\". and have 4 characters."); 
          System.out.println(""); 
         } 
        } 

        loop = true; 
        while (loop) { 
         System.out.print("What is the Processor Speed: "); 
         xx.setCPUspeed(scan.nextLine().toUpperCase()); 
         try { 
          if (StringisDouble(xx.getCPUspeed().substring(0, (xx.getCPUspeed().length() - 2))) || 
            StringisDouble(xx.getCPUspeed().substring(0, (xx.getCPUspeed().length() - 3)))) { //checks the value before GHZ or HZ if its a double 
           if (xx.getCPUspeed().endsWith("GHZ") || xx.getCPUspeed().endsWith("HZ")) { 
            loop = false; 
           } else { 
            System.out.println("CPU Speed input should end with \"GHZ\" or \"HZ\"."); 
            System.out.println(""); 
           } 
          } else { 
           System.out.println("CPU Speed input should contain a decimal or number followed by a \"GHZ\" or a \"HZ\"."); 
           System.out.println(""); 
          } 
         } catch (StringIndexOutOfBoundsException e) { 
          System.out.println("CPU Speed input should contain a decimal or number followed by a \"GHZ\" or a \"HZ\"."); 
          System.out.println(""); 
         } 

        } 

        loop = true; 
        while (loop) { 
         System.out.print("What is the RAM: "); 
         xx.setRAM(scan.nextLine().toUpperCase()); 
         try { 
          if (StringisInteger(xx.getRAM().substring(0, (xx.getRAM().length() - 2)))) {  //checks the value if it is numeric and ending with GB or MB 
           if (xx.getRAM().endsWith("GB") || xx.getRAM().endsWith("MB")) { 
            loop = false; 
           } else { 
            System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\"."); 
            System.out.println(""); 
           } 
          } else { 
           System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\"."); 
           System.out.println(""); 
          } 
         } catch (StringIndexOutOfBoundsException e) { 
          System.out.println("RAM input should have a numeric value and end with \"GB\" or \"MB\"."); 
          System.out.println(""); 
         } 


        } 

        loop = true; 
        while (loop) { 
         System.out.print("What is the Harddisk size: "); 
         xx.setHarddisk(scan.nextLine().toUpperCase()); 
         try { 
          if (StringisInteger(xx.getHarddisk().substring(0, (xx.getHarddisk().length() - 2)))) {  //checks the value if it is numeric and ending with GB or MB 
           if (xx.getHarddisk().endsWith("GB") || xx.getHarddisk().endsWith("TB")) { 
            loop = false; 
           } else { 
            System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\"."); 
            System.out.println(""); 
           } 
          } else { 
           System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\"."); 
           System.out.println(""); 
          } 
         } catch (StringIndexOutOfBoundsException e) { 
          System.out.println("Harddisk input should have a numeric value and end with \"GB\" or \"TB\"."); 
          System.out.println(""); 
         } 
        } 


        loop = true; 
        while (loop) { 
         System.out.print("What is the Monitor: "); 
         xx.setMonitor(scan.nextLine().toUpperCase()); 
         if (xx.getMonitor().equals("CRT") || xx.getMonitor().equals("LCD")) { 
          loop = false; 
         } else { 
          System.out.println("Please enter in CRT or LCD only."); 
          System.out.println(""); 
         } 
        } 

        loop = true; 
        while (loop) { 
         try { 
          System.out.print("What is the price: $"); 
          xx.setPrice(Double.parseDouble(scan.nextLine())); 
          loop = false; 
         } catch (NumberFormatException e) { 
          System.out.println("Price input should be numeric."); 
          System.out.println(""); 
         } 
        } 

        desktopList.add(xx); 

        System.out.println("Information successfully added."); 
        System.out.println(""); 
        System.out.println(""); 
        break; 

       case "3": 
        int DesktopCounter = 1; 
        int LaptopCounter = 1; 

        System.out.println(""); 
        if (desktopList.isEmpty()) { 
         System.out.println("No desktop added!"); 
         System.out.println(""); 
        } else { 
         for (int i = 0; i < desktopList.size(); i++) { 
          System.out.println(""); 
          System.out.println("Desktop " + DesktopCounter); 
          System.out.println("Computer ID: " + desktopList.get(i).getComputerID()); 
          System.out.println("Processor Speed: " + desktopList.get(i).getCPUspeed()); 
          System.out.println("RAM: " + desktopList.get(i).getRAM()); 
          System.out.println("Harddisk:" + desktopList.get(i).getHarddisk()); 
          System.out.println("Monitor: " + desktopList.get(i).getMonitor()); 
          System.out.println("Price: $" + f.format(desktopList.get(i).getPrice())); 
          DesktopCounter++; 
         } 
        } 
        break; 
      } 
     } 
    } 

    private static boolean StringisInteger(String substring) {return true;} 

    private static boolean StringisDouble(String substring) { return true; }

我桌面类看起来是这样的：

@Data 
public class Desktop { 

    private double price; 
    private String computerID; 
    private String CPUspeed; 
    private String RAM; 
    private String harddisk; 
    private String monitor; 

}

凡@Data是龙目注释生成getter和setter方法。正如你所看到的，这些字段不是静态的。

来源

2016-11-22 05:15:19

+0

嗨，感谢您的帮助，但我仍然无法获得正确的输出，即使我已经使setter非静态。我还添加了Desktop类和Computer类。 –

+0

'私有静态字符串监视器; '这些字段不应该是静态的，删除static关键字：'private String monitor' –

+0

我编辑了我的答案，希望它对你有效 –

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