TextFileTest.java Source code

Introduction

Here is the source code for TextFileTest.java

Source

/*
   This program is a part of the companion code for Core Java 8th ed.
   (http://horstmann.com/corejava)
    
   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
    
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
    
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Scanner;

/**
 * @version 1.12 2007-06-22
 * @author Cay Horstmann
 */
public class TextFileTest {
    public static void main(String[] args) {
        Employee[] staff = new Employee[3];

        staff[0] = new Employee("Carl Cracker", 75000, 1987, 12, 15);
        staff[1] = new Employee("Harry Hacker", 50000, 1989, 10, 1);
        staff[2] = new Employee("Tony Tester", 40000, 1990, 3, 15);

        try {
            // save all employee records to the file employee.dat
            PrintWriter out = new PrintWriter("employee.dat");
            writeData(staff, out);
            out.close();

            // retrieve all records into a new array
            Scanner in = new Scanner(new FileReader("employee.dat"));
            Employee[] newStaff = readData(in);
            in.close();

            // print the newly read employee records
            for (Employee e : newStaff)
                System.out.println(e);
        } catch (IOException exception) {
            exception.printStackTrace();
        }
    }

    /**
     * Writes all employees in an array to a print writer
     * @param employees an array of employees
     * @param out a print writer
     */
    private static void writeData(Employee[] employees, PrintWriter out) throws IOException {
        // write number of employees
        out.println(employees.length);

        for (Employee e : employees)
            e.writeData(out);
    }

    /**
     * Reads an array of employees from a scanner
     * @param in the scanner
     * @return the array of employees
     */
    private static Employee[] readData(Scanner in) {
        // retrieve the array size
        int n = in.nextInt();
        in.nextLine(); // consume newline

        Employee[] employees = new Employee[n];
        for (int i = 0; i < n; i++) {
            employees[i] = new Employee();
            employees[i].readData(in);
        }
        return employees;
    }
}

class Employee {
    public Employee() {
    }

    public Employee(String n, double s, int year, int month, int day) {
        name = n;
        salary = s;
        GregorianCalendar calendar = new GregorianCalendar(year, month - 1, day);
        hireDay = calendar.getTime();
    }

    public String getName() {
        return name;
    }

    public double getSalary() {
        return salary;
    }

    public Date getHireDay() {
        return hireDay;
    }

    public void raiseSalary(double byPercent) {
        double raise = salary * byPercent / 100;
        salary += raise;
    }

    public String toString() {
        return getClass().getName() + "[name=" + name + ",salary=" + salary + ",hireDay=" + hireDay + "]";
    }

    /**
     * Writes employee data to a print writer
     * @param out the print writer
     */
    public void writeData(PrintWriter out) {
        GregorianCalendar calendar = new GregorianCalendar();
        calendar.setTime(hireDay);
        out.println(name + "|" + salary + "|" + calendar.get(Calendar.YEAR) + "|"
                + (calendar.get(Calendar.MONTH) + 1) + "|" + calendar.get(Calendar.DAY_OF_MONTH));
    }

    /**
     * Reads employee data from a buffered reader
     * @param in the scanner
     */
    public void readData(Scanner in) {
        String line = in.nextLine();
        String[] tokens = line.split("\\|");
        name = tokens[0];
        salary = Double.parseDouble(tokens[1]);
        int y = Integer.parseInt(tokens[2]);
        int m = Integer.parseInt(tokens[3]);
        int d = Integer.parseInt(tokens[4]);
        GregorianCalendar calendar = new GregorianCalendar(y, m - 1, d);
        hireDay = calendar.getTime();
    }

    private String name;
    private double salary;
    private Date hireDay;
}