I've used Abstract classes and static methods wherever they seemed to be convenient. I've serialized the hashmap entry and read/write it from/to a file.
Please review my code and point me to the mistakes I made. How far away am I from writing production quality code? What are the major drawbacks in my code/design?
import java.io.*;
import java.util.*;
public class Main {
public static void main(String args[]) {
int prompt;
File myfine = new File("std.bat");
Scanner sc = new Scanner(System.in);
if (myfine.length() > 0) {
try (ObjectInputStream ois = new ObjectInputStream(new FileInputStream("std.bat"))) {
Authentication.uniqueStudent = (HashMap<String, Student>) ois.readObject();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
while (true) {
System.out.println("If you want to make a fresh entry PRESS 1 \n If you want to manipulate data in an existing student entry PRESS 2 " +
"\n If you want to save and quit PRESS 3");
prompt = sc.nextInt();
sc.nextLine();
switch (prompt) {
case 1:
Student s1 = new Student();
System.out.println("Enter the student name");
String temp = sc.nextLine();
s1.setName(temp);
System.out.println("Enter the Student Grade");
int grade = sc.nextInt();
s1.setGrade(grade);
s1.setID();
Authentication.uniqueStudent.put(s1.getID(), s1);
System.out.println("The unique student ID is " + s1.getID());
break;
case 2:
System.out.println("Enter the student ID");
String str = sc.nextLine();
if (Authentication.uniqueStudent.containsKey(str)) {
Student objective = Authentication.uniqueStudent.get(str);
System.out.println("The students name is " + objective.getName() + "\nThe students grade is " + objective.getGrade());
System.out.println("The subjects taken by the student are");
ArrayList<Courses> c = objective.getCourses();
if (c != null) {
for (Courses cr : c) {
System.out.println(cr.toString());
}
}
else if(c==null){
System.out.println("The student has not enrolled in any course ");
}
System.out.println("The balance in the students account is " + objective.getTotalMoney());
if (objective.getTotalMoney() >= 800) {
System.out.println("You have enough money to take " + (objective.getTotalMoney() / 800) + " more courses");
System.out.println("Would you like to take more courses ? \nEnter 1 for yes \n" +
"Enter 2 for no");
int token = sc.nextInt();
sc.nextLine();
if (token == 1) {
HashSet<Courses> allCourses = new HashSet<>();
for (Courses cs : Courses.values()) {
allCourses.add(cs);
}
if (c != null) allCourses.removeAll(c);
System.out.println("Select from the following courses");
for (Courses course : allCourses) {
System.out.println(course);
}
String stringu=sc.nextLine();
Courses crs=null;
try {
crs=Courses.valueOf(stringu);
}
catch (IllegalArgumentException e){
System.out.println("Wrong Subject entered try again");
continue;
}
System.out.println("Debugging "+crs);
objective.addSubject(crs);
System.out.println("Now the student has ");
for(Courses cs: objective.getCourses()){
System.out.println(cs);
}
}
}
} else {
System.out.println("Invalid Student ID");
}
break;
case 3:
try (ObjectOutputStream ois = new ObjectOutputStream(new FileOutputStream("std.bat"))) {
ois.writeObject(Authentication.uniqueStudent);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
System.out.println("Saving and Quiting");
return;
}
}
}
}
public enum Courses {
history101,
mathmatics101,
english101,
chemistry101,
computerscience101;
}
import java.io.Serializable;
import java.util.ArrayList;
public class Student implements Serializable {
private String name;
private String ID;
private ArrayList<Courses> courses=new ArrayList<>();
private int totalMoney=3200;
public int getGrade() {
return grade;
}
public void setGrade(int grade) {
this.grade = grade;
}
private int grade;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getID() {
return ID;
}
public void setID() {
String pick ="abcdefghijklmnopqrstuvwxyz12345";
String unique = "" + getGrade();
do {
unique=""+getGrade();
for (int i = 0; i < 4; i++) {
int index = (int) (Math.random() * pick.length());
unique+=pick.charAt(index);
}
}while (Authentication.uniqueStudent.containsKey(unique));
this.ID = unique;
}
public ArrayList<Courses> getCourses() {
return courses;
}
public void setCourses(ArrayList<Courses> courses) {
this.courses = courses;
}
public int getTotalMoney() {
return totalMoney;
}
public void setTotalMoney() {
this.totalMoney -=800;
}
public void addSubject(Courses obj){
setTotalMoney();
courses.add(obj);
}
public static void main(String args[]){
Student stu=new Student();
stu.addSubject(Courses.chemistry101);
}
}
import java.util.HashMap;
public abstract class Authentication {
public static HashMap<String,Student> uniqueStudent=new HashMap<>();
}
