静态员工编号，文件处理问题
Static Employee number, file handling issue
我的员工编号静态变量在处理文件时遇到问题。当我创建一个新员工时，我会自动按顺序获取下一个数字。但是当我重新启动程序并尝试创建一个新的员工时，员工编号恢复为 1。
有没有任何人可能会建议阅读前任员工并从那里继续编号的方法？
提前感谢您的帮助！！ :)
@SuppressWarnings("serial")
public class Employee extends Person implements Serializable
{
private Date dateOfBirth;
private Date startDate;
private double salary;
private int employeeNumber;
private static int nextEmployeeNumber = 1;
private final double MAX_SALARY = 70000;
private final double INCREMENT = 250;
public Employee()
{
super();
dateOfBirth = new Date();
startDate = new Date();
salary = 0.0;
employeeNumber = nextEmployeeNumber++;
}
public Employee(String title, String firstName, String surname, String phoneNumber,
int day, int month, int year, int sD, int sM, int sY, double salary)
{
super(title, firstName, surname, phoneNumber);
this.dateOfBirth = new Date(day, month, year);
this.startDate = new Date(sD, sM, sY);
this.employeeNumber = employeeNumber++;
this.salary = salary;
}
//Overrides the toString methods, providing its own implementation
@Override
public String toString()
{
return(super.toString() + "\nEmployee Number: " + employeeNumber + "\nEmployee Salary: " + salary +
"\nEmployee DOB: " + dateOfBirth + "\nEmployee Start Date: " + startDate);
}
//Both .equals methods are usable. To save any possible conflicts as might occur
//in a larger system, I have set the equals method to call back to the Object class
@Override
public boolean equals(Object otherObject)
{
Employee other = (Employee) otherObject;
if (otherObject == null)
{
return false;
}
if(getClass() != otherObject.getClass())
{
return false;
}
if(super.name.equals(otherObject)&&
(employeeNumber == other.employeeNumber)&&
(dateOfBirth == other.dateOfBirth)&&
(startDate == other.startDate)&&
(salary == other.salary));
{
return true;
}
}
int quit = 0;
public void read()
{
Scanner kbInt = new Scanner(System.in);
Scanner kbString = new Scanner(System.in);
System.out.print("\n\nEmployee Title: ");
name.title = kbString.nextLine();
System.out.print("\nEmployee First Name: ");
name.firstName = kbString.nextLine();
System.out.print("\nEmployee Surname: ");
name.surname = kbString.nextLine();
System.out.print("\nEmployee DOB Day: ");
dateOfBirth.day = kbInt.nextInt();
System.out.print("\nEmployee DOB Month: ");
dateOfBirth.month = kbInt.nextInt();
System.out.print("\nEmployee DOB Year: ");
dateOfBirth.year = kbInt.nextInt();
System.out.print("\nEmployee Phone Number: ");
phoneNumber = kbString.nextLine();
System.out.print("\nEmployee Start Day: ");
startDate.day = kbString.nextInt();
System.out.print("\nEmployee Start Month: ");
startDate.month = kbString.nextInt();
System.out.print("\nEmployee Start Year: ");
startDate.year = kbString.nextInt();
System.out.print("\nEmployee Salary: ");
salary = kbInt.nextDouble();
}
//Getters & Setters of DOB, start date, employee number & salary
public Date getDateOfBirth()
{
return dateOfBirth;
}
public void setStartDate(Date startDate)
{
this.startDate = startDate;
}
public Date getstartDate()
{
return startDate;
}
public void setDateOfBirth(Date dateOfBirth)
{
this.dateOfBirth = dateOfBirth;
}
public int getEmployeeNumber()
{
return employeeNumber;
}
public double getSalary()
{
return salary;
}
public void setSalary(double salary) throws IllegalArgumentException
{
this.salary = salary;
if(salary < 0 || salary > 70000)
throw new IllegalArgumentException("Enter Valid Salary");
}
public void incrementSalary()
{
if(salary + INCREMENT <= MAX_SALARY)
salary += INCREMENT;
else
salary = MAX_SALARY;
}
}
import java.util.*;
import java.io.*;
import java.nio.file.*;
/**
* Class B.Sc. CSDF
* Instructor Maria Boyle
* Description: EmployeeMenu class for Hotel application
* Date: 01/11/2015
* @author Mark Melling
* @version 1.0
*/
////////////////////////////////////////////////////////////////////////
// This class contains an ArrayList, and the methods for modifying //
// the ArrayList as required, as well as the methods for serializing//
// and deserializing the ArrayList //
////////////////////////////////////////////////////////////////////////
@SuppressWarnings("serial")
public class EmployeeFileHandler_1 implements Serializable
{
//Declare ArrayList called employees - for storing a list of Employees
private ArrayList<Employee> employees;
private Scanner keyIn = new Scanner(System.in);
public EmployeeFileHandler_1() // Default Constructor
{
employees = new ArrayList<Employee>(); // Construct Employee ArrayList
}
//////////////////////////////////////////////////////
// Method Name : add() //
// Return Type : void //
// Parameters : None //
// Purpose: Reads one Employee record from the user //
// and adds it to the ArrayList employeeList //
//////////////////////////////////////////////////////
public void add()
{
Employee employee = new Employee(); // Create a Employee object
employee.read(); // Read its details
employees.add(employee); // Add it to the employeeList
}
//////////////////////////////////////////////////////
// Method Name : list() //
// Return Type : void //
// Parameters : None //
// Purpose: Loops around the ArrayList employeeList //
// and prints to screen employee details //
//////////////////////////////////////////////////////
public void list()
{
for(Employee currentEmployee : employees)
{
System.out.println(currentEmployee);
}
}
//////////////////////////////////////////////////////
// Method Name: view() //
// Return Type: void //
// Parameters: None //
// Purpose: View Employee record from the //
// ArrayList employeeList //
//////////////////////////////////////////////////////
public void view()
{
//Read the number of the Employee to be viewed
System.out.println("\nEnter Employee Number:");
int employeeToView = keyIn.nextInt();
//Read every Employee object in videos
for(Employee currentEmployee : employees)
{
// If it's number equals the number of the Employee to view
if(currentEmployee.getEmployeeNumber() == employeeToView)
{
//Display Employee
System.out.println(currentEmployee);
break;
}
}
}
////////////////////////////////////////////////////////
// Method Name: delete() //
// Return Type: void //
// Parameters: None //
// Purpose: Reads Employee record from the //
// ArrayList employeeList & deletes user //
////////////////////////////////////////////////////////
public void delete()
{
//Read the number of the video to be deleted from the user
System.out.println("Enter Number of Employee To Delete");
int employeeToDelete = keyIn.nextInt();
//for every Video object in videos
for(Employee currentEmployee : employees)
{
//if it's number equals the number of the Video to view
if(currentEmployee.getEmployeeNumber() == employeeToDelete)
{
//display it
System.out.println(currentEmployee);
//Remove it from videos
employees.remove(currentEmployee);
break;
}
}
}
////////////////////////////////////////////////////////
// Method Name: delete() //
// Return Type: void //
// Parameters: None //
// Purpose: Reads Employee record from the //
// ArrayList employeeList & edits user //
////////////////////////////////////////////////////////
public void edit()
{
//Read the number of the employee to be edited from the user
System.out.println("Enter number of Employee to edit");
int employeeToEdit = keyIn.nextInt();
//for every Employee object in employees
for(Employee currentEmployee : employees)
{
//if it's number equals the number of the employee to view
if(currentEmployee.getEmployeeNumber() == employeeToEdit)
{
//Display employee
System.out.println(currentEmployee);
//get it's index
int index = employees.indexOf(currentEmployee);
//read in a new employee
currentEmployee.read();
//reset the object in employees
employees.set(index, currentEmployee);
break;
}
}
}
///////////////////////////////////////////////////////
// Method Name : writeRecordsToFile() //
// Return Type : void //
// Parameters : None //
// Purpose: Writes the ArrayList employees to the //
// file employees.bin before closing it //
///////////////////////////////////////////////////////
public void writeRecordsToFile()
{
if(employees instanceof Serializable)
try
{
// Serialize the ArrayList...
FileOutputStream fileStream = new FileOutputStream("employees.bin");
ObjectOutputStream os = new ObjectOutputStream(fileStream);
os.writeObject(employees);
os.close();
}
catch(FileNotFoundException fNFE)
{
System.out.println("Cannot create file to store employees.");
}
catch(Exception e)
{
System.out.println("Input Output Error" + e.getMessage());
}
}
//////////////////////////////////////////////////////////
// Method Name: readRecordsToFile() //
// Return Type: void //
// Parameters: None //
// Purpose: Reads the ArrayList employees from the //
// file employees.bin, uses the Path.get //
// method to test whether the path to the //
// file exists & adds error handling. //
//////////////////////////////////////////////////////////
@SuppressWarnings("unchecked")
public void readRecordsFromFile()
{
if(employees instanceof Serializable)
try
{
final String FILENAME = "employees.bin";
Path p = Paths.get(FILENAME);
if(Files.exists(p))
{
//Creates Object
FileInputStream inputStream = new FileInputStream(p.toString());
ObjectInputStream is = new ObjectInputStream(inputStream);
Object o = is.readObject(); //READ an Object from the file
if(o instanceof ArrayList) //IF Object is an ArrayList
employees = (ArrayList<Employee>)o; //ASSIGN Object to employees
is.close();
}
else
{
System.out.println("File "+p.getFileName() + "Doesnt exist");
}
}
catch(FileNotFoundException fNFE)
{
System.out.println("File not found " + fNFE.getMessage());
}
catch(IOException iOE)
{
System.out.println("Input output error " + iOE.getMessage());
}
catch(Exception e)
{
System.out.println(e.getMessage());
}
}
}
你需要 serialise/persist 为此你的数据。这可以通过将数据写入文件、使用数据库或其他方法来完成。
然后您可以从 database/file 中读取您的数据以检索所有持久条目并找出下一个员工编号。
** 编辑 **
你编辑了我的答案而不是发布它
我的员工编号静态变量在处理文件时遇到问题。当我创建一个新员工时，我会自动按顺序获取下一个数字。但是当我重新启动程序并尝试创建一个新的员工时，员工编号恢复为 1。
有没有任何人可能会建议阅读前任员工并从那里继续编号的方法？
提前感谢您的帮助！！ :)
@SuppressWarnings("serial")
public class Employee extends Person implements Serializable
{
private Date dateOfBirth;
private Date startDate;
private double salary;
private int employeeNumber;
private static int nextEmployeeNumber = 1;
private final double MAX_SALARY = 70000;
private final double INCREMENT = 250;
public Employee()
{
super();
dateOfBirth = new Date();
startDate = new Date();
salary = 0.0;
employeeNumber = nextEmployeeNumber++;
}
public Employee(String title, String firstName, String surname, String phoneNumber,
int day, int month, int year, int sD, int sM, int sY, double salary)
{
super(title, firstName, surname, phoneNumber);
this.dateOfBirth = new Date(day, month, year);
this.startDate = new Date(sD, sM, sY);
this.employeeNumber = employeeNumber++;
this.salary = salary;
}
//Overrides the toString methods, providing its own implementation
@Override
public String toString()
{
return(super.toString() + "\nEmployee Number: " + employeeNumber + "\nEmployee Salary: " + salary +
"\nEmployee DOB: " + dateOfBirth + "\nEmployee Start Date: " + startDate);
}
//Both .equals methods are usable. To save any possible conflicts as might occur
//in a larger system, I have set the equals method to call back to the Object class
@Override
public boolean equals(Object otherObject)
{
Employee other = (Employee) otherObject;
if (otherObject == null)
{
return false;
}
if(getClass() != otherObject.getClass())
{
return false;
}
if(super.name.equals(otherObject)&&
(employeeNumber == other.employeeNumber)&&
(dateOfBirth == other.dateOfBirth)&&
(startDate == other.startDate)&&
(salary == other.salary));
{
return true;
}
}
int quit = 0;
public void read()
{
Scanner kbInt = new Scanner(System.in);
Scanner kbString = new Scanner(System.in);
System.out.print("\n\nEmployee Title: ");
name.title = kbString.nextLine();
System.out.print("\nEmployee First Name: ");
name.firstName = kbString.nextLine();
System.out.print("\nEmployee Surname: ");
name.surname = kbString.nextLine();
System.out.print("\nEmployee DOB Day: ");
dateOfBirth.day = kbInt.nextInt();
System.out.print("\nEmployee DOB Month: ");
dateOfBirth.month = kbInt.nextInt();
System.out.print("\nEmployee DOB Year: ");
dateOfBirth.year = kbInt.nextInt();
System.out.print("\nEmployee Phone Number: ");
phoneNumber = kbString.nextLine();
System.out.print("\nEmployee Start Day: ");
startDate.day = kbString.nextInt();
System.out.print("\nEmployee Start Month: ");
startDate.month = kbString.nextInt();
System.out.print("\nEmployee Start Year: ");
startDate.year = kbString.nextInt();
System.out.print("\nEmployee Salary: ");
salary = kbInt.nextDouble();
}
//Getters & Setters of DOB, start date, employee number & salary
public Date getDateOfBirth()
{
return dateOfBirth;
}
public void setStartDate(Date startDate)
{
this.startDate = startDate;
}
public Date getstartDate()
{
return startDate;
}
public void setDateOfBirth(Date dateOfBirth)
{
this.dateOfBirth = dateOfBirth;
}
public int getEmployeeNumber()
{
return employeeNumber;
}
public double getSalary()
{
return salary;
}
public void setSalary(double salary) throws IllegalArgumentException
{
this.salary = salary;
if(salary < 0 || salary > 70000)
throw new IllegalArgumentException("Enter Valid Salary");
}
public void incrementSalary()
{
if(salary + INCREMENT <= MAX_SALARY)
salary += INCREMENT;
else
salary = MAX_SALARY;
}
}
import java.util.*;
import java.io.*;
import java.nio.file.*;
/**
* Class B.Sc. CSDF
* Instructor Maria Boyle
* Description: EmployeeMenu class for Hotel application
* Date: 01/11/2015
* @author Mark Melling
* @version 1.0
*/
////////////////////////////////////////////////////////////////////////
// This class contains an ArrayList, and the methods for modifying //
// the ArrayList as required, as well as the methods for serializing//
// and deserializing the ArrayList //
////////////////////////////////////////////////////////////////////////
@SuppressWarnings("serial")
public class EmployeeFileHandler_1 implements Serializable
{
//Declare ArrayList called employees - for storing a list of Employees
private ArrayList<Employee> employees;
private Scanner keyIn = new Scanner(System.in);
public EmployeeFileHandler_1() // Default Constructor
{
employees = new ArrayList<Employee>(); // Construct Employee ArrayList
}
//////////////////////////////////////////////////////
// Method Name : add() //
// Return Type : void //
// Parameters : None //
// Purpose: Reads one Employee record from the user //
// and adds it to the ArrayList employeeList //
//////////////////////////////////////////////////////
public void add()
{
Employee employee = new Employee(); // Create a Employee object
employee.read(); // Read its details
employees.add(employee); // Add it to the employeeList
}
//////////////////////////////////////////////////////
// Method Name : list() //
// Return Type : void //
// Parameters : None //
// Purpose: Loops around the ArrayList employeeList //
// and prints to screen employee details //
//////////////////////////////////////////////////////
public void list()
{
for(Employee currentEmployee : employees)
{
System.out.println(currentEmployee);
}
}
//////////////////////////////////////////////////////
// Method Name: view() //
// Return Type: void //
// Parameters: None //
// Purpose: View Employee record from the //
// ArrayList employeeList //
//////////////////////////////////////////////////////
public void view()
{
//Read the number of the Employee to be viewed
System.out.println("\nEnter Employee Number:");
int employeeToView = keyIn.nextInt();
//Read every Employee object in videos
for(Employee currentEmployee : employees)
{
// If it's number equals the number of the Employee to view
if(currentEmployee.getEmployeeNumber() == employeeToView)
{
//Display Employee
System.out.println(currentEmployee);
break;
}
}
}
////////////////////////////////////////////////////////
// Method Name: delete() //
// Return Type: void //
// Parameters: None //
// Purpose: Reads Employee record from the //
// ArrayList employeeList & deletes user //
////////////////////////////////////////////////////////
public void delete()
{
//Read the number of the video to be deleted from the user
System.out.println("Enter Number of Employee To Delete");
int employeeToDelete = keyIn.nextInt();
//for every Video object in videos
for(Employee currentEmployee : employees)
{
//if it's number equals the number of the Video to view
if(currentEmployee.getEmployeeNumber() == employeeToDelete)
{
//display it
System.out.println(currentEmployee);
//Remove it from videos
employees.remove(currentEmployee);
break;
}
}
}
////////////////////////////////////////////////////////
// Method Name: delete() //
// Return Type: void //
// Parameters: None //
// Purpose: Reads Employee record from the //
// ArrayList employeeList & edits user //
////////////////////////////////////////////////////////
public void edit()
{
//Read the number of the employee to be edited from the user
System.out.println("Enter number of Employee to edit");
int employeeToEdit = keyIn.nextInt();
//for every Employee object in employees
for(Employee currentEmployee : employees)
{
//if it's number equals the number of the employee to view
if(currentEmployee.getEmployeeNumber() == employeeToEdit)
{
//Display employee
System.out.println(currentEmployee);
//get it's index
int index = employees.indexOf(currentEmployee);
//read in a new employee
currentEmployee.read();
//reset the object in employees
employees.set(index, currentEmployee);
break;
}
}
}
///////////////////////////////////////////////////////
// Method Name : writeRecordsToFile() //
// Return Type : void //
// Parameters : None //
// Purpose: Writes the ArrayList employees to the //
// file employees.bin before closing it //
///////////////////////////////////////////////////////
public void writeRecordsToFile()
{
if(employees instanceof Serializable)
try
{
// Serialize the ArrayList...
FileOutputStream fileStream = new FileOutputStream("employees.bin");
ObjectOutputStream os = new ObjectOutputStream(fileStream);
os.writeObject(employees);
os.close();
}
catch(FileNotFoundException fNFE)
{
System.out.println("Cannot create file to store employees.");
}
catch(Exception e)
{
System.out.println("Input Output Error" + e.getMessage());
}
}
//////////////////////////////////////////////////////////
// Method Name: readRecordsToFile() //
// Return Type: void //
// Parameters: None //
// Purpose: Reads the ArrayList employees from the //
// file employees.bin, uses the Path.get //
// method to test whether the path to the //
// file exists & adds error handling. //
//////////////////////////////////////////////////////////
@SuppressWarnings("unchecked")
public void readRecordsFromFile()
{
if(employees instanceof Serializable)
try
{
final String FILENAME = "employees.bin";
Path p = Paths.get(FILENAME);
if(Files.exists(p))
{
//Creates Object
FileInputStream inputStream = new FileInputStream(p.toString());
ObjectInputStream is = new ObjectInputStream(inputStream);
Object o = is.readObject(); //READ an Object from the file
if(o instanceof ArrayList) //IF Object is an ArrayList
employees = (ArrayList<Employee>)o; //ASSIGN Object to employees
is.close();
}
else
{
System.out.println("File "+p.getFileName() + "Doesnt exist");
}
}
catch(FileNotFoundException fNFE)
{
System.out.println("File not found " + fNFE.getMessage());
}
catch(IOException iOE)
{
System.out.println("Input output error " + iOE.getMessage());
}
catch(Exception e)
{
System.out.println(e.getMessage());
}
}
}
你需要 serialise/persist 为此你的数据。这可以通过将数据写入文件、使用数据库或其他方法来完成。
然后您可以从 database/file 中读取您的数据以检索所有持久条目并找出下一个员工编号。
** 编辑 ** 你编辑了我的答案而不是发布它