Hey i am stuck on an add method for my ArrayList store students which then writes the student store to a text file using randomAccessFile. So i need to be able to add a student to the store and then write it to the file. Can anyone suggest a way i can do this ? I can add the student to the store no problem but the actual problem is that i am writing the students to the file using a static array and im not sure how i would go about letting the user add the new employee to the static array?
Here is my code:
MainApp
import java.io.IOException;
import java.io.RandomAccessFile;
public class MainApp
{
public static void main(String[] args) throws Exception
{
new MainApp().start();
}
public void start()throws Exception
{
StudentStore details = new StudentStore();
Student a = new Student("Becky O'Brien", "DKIT26", "0876126944", "bexo@hotmail.com");
Student b = new Student("Fabio Borini", "DKIT28", "0876136944", "fabioborini@gmail.com");
Student c = new Student("Gaston Ramirez", "DKIT29", "0419834501", "gramirez@webmail.com");
Student d = new Student("Luis Suarez", "DKIT7", "0868989878", "luissuarez@yahoo.com");
Student e = new Student("Andy Carroll", "DKIT9", "0853456788", "carroll123@hotmail.com");
details.add(a);
details.add(b);
details.add(c);
details.add(d);
details.add(e);
//details.print();
RandomAccessFile file = new RandomAccessFile("ContactDetails.txt","rw");
//getBytes() returns an array of bytes.
//Because i have put the store in a static Array.(I done this because i could find no other
//Simple way to write a Student Object.)
//None of the methods of the RandomAccessFile write class worked with this.
Student[] students = {a,b,c,d,e};
details.write(students, file);
details.readAll(file);
file.close();
}
}
StudentStore
//---------------------------------------------------------------------------
//Imports.
//---------------------------------------------------------------------------
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.ArrayList;
import java.util.List;
//---------------------------------------------------------------------------
public class StudentStore
{
//---------------------------------------------------------------------------
//ArrayList declaration.
//---------------------------------------------------------------------------
List<Student> students = new ArrayList<Student>();
//---------------------------------------------------------------------------
//Name: Add method.
//Description: Adds a student to the ArrayList.
//---------------------------------------------------------------------------
public void add(Student student)
{
students.add(student);
}
//---------------------------------------------------------------------------
//Name: DeleteAll method.
//Description: Delete's everything in the ArrayList.
//---------------------------------------------------------------------------
public void deleteAll()
{
students.clear();
}
//---------------------------------------------------------------------------
//Name: Print method.
//Description: Prints out the contents of the ArrayList.
//---------------------------------------------------------------------------
public void print()
{
for (int i = 0; i < students.size(); i++)
{
Student a = students.get(i);
System.out.println(a.toString());
}
}
public int size()
{
return (students == null) ? 0 : students.size();
}
public void write(Student[] students, RandomAccessFile file) throws IOException
{
for (int i = 0; i < students.length; i++)
{
byte[] bytes = students[i].toString().getBytes();
for(byte byteWrite : bytes)
{
file.writeByte(byteWrite);
}
}
}
public void readAll(RandomAccessFile file) throws IOException
{
final int Record_Length = 30;
int recordNumber = 0;
file.seek((recordNumber) * Record_Length);
String code ="";
for(int i = 0; i < 30; i++)
{
code += file.readLine() + "\n";
}
System.out.println(code);
}
}
Note: I havent shown the student class because it is built up of a constructor, getters and setters and a toString and i didnt feel the use of uploading it but if needed i will gladly do it.
