不能正確添加到數組。希望獲得幫助

Question

我使用BlueJ作爲參考。

該程序編譯並運行良好。

問題是，我相信我應該加入到現有的數組中，但相反，它似乎我只是添加到一個新的。

程序讀取稱爲「EmployeeData.TXT」這個文本文件：

S  Washington,George  000001  125000 
H MacDonald,Ronald  386218  7.80 true 40 
H  Walton,Samuel   268517 8.21 false 
H Thomas,David   131313 9.45 true 38 
H Sanders,HarlandDavid 277651 8.72 false 
S Baron,James   368535 310236 

我應該被加入（除其他事項外）這一點。

當我添加一個員工時，它不顯示它與上面的員工列表，它根本不顯示該列表。

這是我目前得到的輸出片段，顯示它不包含文本文件數據。

S, Ghandhi, Mohandas 1111 150000.0 
H, Luther, Maritn 2222 10.5 false false 
H, Mandela, Nelson 3333 12.5 true true 40 

另外，我不知道爲什麼有一個逗號的S/H後到來。是什麼導致它不能添加到從文本文件所帶來的數據？

這裏是我的主類，WorkerApp：

public class WorkerApp{ 
    public static void main (String args[]){ 
     Company company = new Company(); 
     try{ 
      Scanner reader = new Scanner (new File("EmployeeData.txt")); 
      while(reader.hasNext()){ 
       String line = reader.nextLine(); 
       String Employee[] = new String[7]; 
       String sorh = Employee[0]; 
       String name = Employee[1]; 
       String id = Employee[2]; 
       double salary = Double.parseDouble(Employee[3]); 
       Employee e; 
       if (Employee[0].equals("S")){ 
        e = new SalariedWorker(sorh, name, id, salary);} 
       else { 
        boolean overtime = Boolean.parseBoolean(Employee[4]); 
        if(overtime){ 
         int maxhu = Integer.parseInt(Employee[5]); 
         e = new HourlyWorker(sorh, name, id, salary, maxhu); 
        } 
        else{ 
         e = new HourlyWorker(sorh, name, id, salary); 
        } 
       } 
       company.add(e); 
      } 
     }catch (Exception err){ 
      System.out.println("Cannot open EmployeeData.TXT."); 
     } 

     System.out.println("REPORT"); 
     company.print(); 
     System.out.println(); 

     System.out.println("1. Adding a salaried worker"); 
     SalariedWorker s1 = new SalariedWorker("S", "Ghandhi, Mohandas", "1111", 150000); 
     company.add(s1); 
     System.out.println(); 
     System.out.println("this will trigger the expand capacity method"); 
     HourlyWorker h1 = new HourlyWorker("H", "Luther, Maritn", "2222", 10.5); 
     company.add(h1); 
     System.out.println(); 
     System.out.println("3, Adding an hourly worker who has overtime allowed."); 
     HourlyWorker h2 = new HourlyWorker("H", "Mandela, Nelson", "3333", 12.5, 40); 
     company.add(h2); 
     System.out.println(); 
     System.out.println("4. Adding a worker that is already in the database"); 

     try{ 
      company.add(s1); 
     }catch(Exception e){ 
      System.out.println(e); 
      System.out.println(); 
     } 

     System.out.println(); 
     System.out.println("5. Printing the sorted list."); 
     company.print(); 
     System.out.println(); 
     System.out.println("6,. Removing a worker who is Not in the list."); 

     SalariedWorker s2 = new SalariedWorker("S", "Parks, Rosa", "5555", 11600); 
     company.remove("abc"); 
     System.out.println(); 

     System.out.println("7. Removing a worker who is the first in the list"); 
     company.remove("Baron, James"); 
     System.out.println(); 

     System.out.println("8. Finding a worker who is the middle of the list."); 
     int index = company.find("Newton, Isaac"); 
     System.out.println("Found at "+index); 
     System.out.println(); 

     System.out.println("9. Finding a worker who is not in the list."); 
     index = company.find("xyz, abc"); 
     System.out.println("Found at "+index); 
     System.out.println(); 

     System.out.println("10. Finding the weekly salary of a worker who is salaried"); 
     System.out.println(s1.FindSalary()); 
     System.out.println(); 

     System.out.println("11. FInd the weekly Salary of an hourly worker who has no overtime allowed."); 
     System.out.println("[Entering a time of 50 hours]"); 
     System.out.println(h1.FindSalary(50)); 
     System.out.println(); 

     System.out.println("12, FInd the weekly Salary of an hourly worker who has overtime allowed."); 
     System.out.println("[Entering the time of 50 hours]"); 
     System.out.println(h2.FindSalary(50)); 
     System.out.println(); 

     System.out.println("13. FInd the weekly Salary of an hourly worker who has overtime allowed."); 
     System.out.println("[Entering a time of 20 hours]"); 
     System.out.println(h2.FindSalary(20)); 
     System.out.println(); 

     System.out.println("14. Printing the sorted list."); 
     company.print(); 
    } 
} 

也許我的問題就出在我的公司類？

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

public class Company{ 
    private Employee[] employeeArray; 
    private final int InitialCapacity = 7; 
    private int employCount; 

    public Company(){ 
     employeeArray = new Employee[InitialCapacity]; 
     employCount = 0; 
    } 

    public int size() { 
     return employCount; 
    } 

    public int find(String name){ 
     for (int i = 0; i < employCount; i++){ 
      if (employeeArray[i].getName().equals(name)){ 
       return i; 
      } 
     } 

     return -1; 
    } 

    public int add(Employee employ){ 
     int index; 

     for (index = 0; index < employCount; index++){ 
      int result = employeeArray[index].getName().compareTo(employ.getName()); 
      if(result == 0){ 
       throw new RuntimeException ("Employee Not New"); 
      } 
     } 

     if (employeeArray.length == employCount){ 
      expand(); 
     } 

     for(int i = employCount; i > index; i--){ 
      employeeArray[i] = employeeArray[i - 1]; 
     } 

     employeeArray[index] = employ; 
     employCount++; 
     return index; 
    } 

    public void remove(String name){ 
     int index = find(name); 
     if (index == -1){ 
      System.out.println("Employee not Found"); 
      return; 
     } 

     for (int i = index; i < employCount - 1; i++){ 
      employeeArray[i] = employeeArray[i + 1]; 
     } 

     employCount--; 
    } 

    public void print(){ 
     if(employCount == 0){ 
      System.out.println("List is Empty"); 
      return; 
     } 
     for(int i = 0; i < employCount; i++){ 
      System.out.println(employeeArray[i]); 
     } 
    } 

    public Object get(int index){ 
     if(index >= 0 && index < employCount){ 
      return employeeArray[index]; 
     }else{ 
      return "List out of Bounds"; 
     } 
    } 

    private void expand(){ 
     Employee[] newArray = new Employee[employeeArray.length + InitialCapacity]; 
     for (int i = 0; i < employeeArray.length; i++){ 
      newArray[i] = employeeArray[i]; 
     } 
     employeeArray = newArray; 
    } 
} 

預先感謝您！

Answer 1

您的插入邏輯看起來很奇怪。如果您希望在數組末尾添加新員工（即在數組中第一個未佔用的位置），則不需要第二個循環。

您只需檢查員工是否已經在陣列中（您的第一個循環），然後在index位置（與employCount相同）添加員工。

public int add(Employee employ) 
{ 
    int index; 
    for (index = 0; index < employCount; index++){ 
     int result = employeeArray[index].getName().compareTo(employ.getName()); 
     if(result == 0){ 
      throw new RuntimeException ("Employee Not New"); 
     } 
    } 

    if (employeeArray.length == employCount){ 
     expand(); 
    } 

    employeeArray[index] = employ; 
    employCount++; 
    return index; 
} 

編輯：

你比我上面提到的一個更大的問題：

  String line = reader.nextLine(); 
      String Employee[] = new String[7]; 

你必須從文件中的行，但也無可奈何它。然後創建一個String數組並開始訪問它的值，即使它們全都爲null。因此，諸如Employee[0].equals("S")等方法調用將導致NullPointerException。

你應該做的是：

  String line = reader.nextLine(); 
      String Employee[] = line.split(" "); // assuming " " is the separator 
               // between tokens in each line 

現在你Employee陣列（你應該支持通話的員工，如果你不想與Employee類相混淆）將包含該行的列你可以在循環的其餘部分訪問它們。