Donor.java

importjava.io.*;
// import java.lang.reflect.Array;
importjava.nio.file.Files;
importjava.nio.file.NoSuchFileException;
importjava.nio.file.Paths;
importjava.text.ParseException;
importjava.text.SimpleDateFormat;
importorg.joda.time.LocalDate;
// import org.joda.time.DateTime;
importorg.joda.time.Period;
importjava.util.ArrayList;
importjava.util.Date;
importjava.util.Iterator;
importjava.util.Scanner;
importjava.util.regex.Matcher;
importjava.util.regex.Pattern;

publicclassDonorimplementsSerializable {
Stringname, addr, contact, bldgrp;
Datedate;

publicstaticvoidmain(String[] args) throwsIOException {

// arraylist for retrieving and adding donors
ArrayList<Donor> ad = newArrayList<Donor>();

intn, i; // counter variables

// format for date and time
SimpleDateFormatft = newSimpleDateFormat("MM-dd-yyyy");
Stringtemp;

// patten for blood group
Stringpattern = "[A|B|O|AB][+|-]";
Matcherm;
Patternr = Pattern.compile(pattern);

// delete existing file first
try {
Files.deleteIfExists(Paths.get("donations.txt"));
 } catch (NoSuchFileExceptione) {
System.out.println("Error: No such file/directory exists");
 } catch (IOExceptione) {
System.out.println("Error: Invalid permissions.");
 }
System.out.println("Success: Deletion successful.");

Scannersc = newScanner(System.in);
System.out.print("Enter number of donors: ");
n = sc.nextInt();
sc.nextLine();
Donord;
System.out.println("----------------------");
for (i = 0; i < n; i++) {
d = newDonor(); // initializing new donor
// taking input from user
System.out.print("Name: ");
d.name = sc.nextLine();
System.out.print("Address: ");
d.addr = sc.nextLine();
System.out.print("Contact: ");
d.contact = sc.nextLine();
d.bldgrp = "";
m = r.matcher(d.bldgrp);
while (!m.find()) {
System.out.print("Blood Group (only A or B or O or AB [+|-] (all caps): ");
d.bldgrp = sc.nextLine();
m = r.matcher(d.bldgrp);
 }
booleanflag = false;
while (!flag) {
System.out.print("Date (MM-dd-yyyy): ");
temp = sc.nextLine();
try {
d.date = ft.parse(temp);
flag = true;
 } catch (ParseExceptione) {
flag = false;
System.out.println("Unparseable using " + ft);
 }
 }

// adding donor object to array list
ad.add(d);
 }
try {
FileOutputStreamfos = newFileOutputStream("donations.txt"); // creating file to write to
ObjectOutputStreamoos = newObjectOutputStream(fos);
// serialization
oos.writeObject(ad);
oos.close();
fos.close();
System.out.println("Success: File successfully written");
 } catch (IOExceptionioe) {
ioe.printStackTrace();
 }

// reading data from file
ad.clear();
FileInputStreamfis = newFileInputStream("donations.txt");
ObjectInputStreamois = newObjectInputStream(fis);
try {
ad = (ArrayList<Donor>) ois.readObject();
 } catch (ClassNotFoundExceptione) {
System.out.println(e);
 }

// defining current time and period
LocalDatedonor_date;
LocalDatecurrent = LocalDate.now();
Periodp;

System.out.println("---------------------------------------------");
System.out.println("---------------------------------------------");
// iterating through the arraylist
System.out.println("\n" + "Donors who haven't donated in 6 months and \"A+\"" + "\n");
Iterator<Donor> itr = ad.iterator();
i = 0;
while (itr.hasNext()) {
d = newDonor();
d = (Donor) itr.next();
donor_date = newLocalDate(d.date);
p = newPeriod(donor_date, current);

// if more than 6 months and blood group is A+, print details
if ((p.getMonths() > 6 | p.getYears() >= 1) && d.bldgrp.equals("A+")) {
System.out.println("Donor " + (i + 1));
System.out.println("----------------------");
System.out.println(d.name); // name
System.out.println(d.addr); // address
System.out.println(d.contact); // contact
System.out.println(d.bldgrp); // blood group
System.out.println(d.date); // date
System.out.println("\n");
 }
 }
 }
}