package randomAccess;

import java.io.IOException;
import java.io.RandomAccessFile;

/**
*   Class to load a set of employee data to a file.
*
*   @author Bryan J. Higgs, 31 January, 2001.
*/
public class EmployeeDataLoader
{
    /**
    *   Main entry point.
    *
    *   @param args command line arguments.
    *               args[0] is the name of the file to load.
    */
    public static void main(String[] args)
    {
        if (args.length < 1)
        {
            System.err.println(
                "Usage: java randomAccess.EmployeeDataLoader <file-to-load>");
            return;
        }
        // Extract the filename
        String fileName = args[0];

        // Construct all employees (empID, empName, empSalary, managedBy)
        Employee bigBoss = new Employee(1, "Richie Rich", 2000000.0, -1);
        Employee cfo     = new Employee(2, "Guy Noire", 200000.0, 1);
        Employee hrBoss  = new Employee(3, "Prescott Hireling", 100000.0, 1);
        Employee sectry  = new Employee(4, "Dottie Magnusson", 40000.0, 3);
        Employee opsBoss = new Employee(5, "Frank Getitdone", 120000.0, 1);
        Employee minion  = new Employee(6, "Joe Duzit", 30000.0, 5);

        RandomAccessFile file = null;
        try
        {
            // Create random access file object for writing.
            file = new RandomAccessFile(fileName, "rw");
            // Write all employees to the file
            // NOTE: The employee ID is the index of the employee data,
            //       so the employees are written in employee ID order.
            bigBoss.write(file);
            cfo.write(file);
            hrBoss.write(file);
            sectry.write(file);
            opsBoss.write(file);
            minion.write(file);
        }
        catch (IOException ex)
        {
            ex.printStackTrace();
        }
        finally
        {
            // Close the file, under all circumstances.
            if (file != null)
            {
                try
                {
                    file.close();
                }
                catch (IOException ex)
                {
                    // Ignore
                }
            }
        }
    }
}