BinaryFIle.java

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import model.Student;

/*
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/**
 *
 * @author majud
 */
public class BinaryFile implements ServletContextListener {

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        ServletContext context = sce.getServletContext();
        List<Student> source = null;
        String filename = "/WEB-INF/Student.dat";
        InputStream is = context.getResourceAsStream(filename);
        if (is != null) {
            try {
                ObjectInputStream objectInputFile = new ObjectInputStream(is);
                source = (List)(objectInputFile.readObject());
            }
            catch(Exception e) {
                System.out.println("Input error!");
            }
            if (source==null) {
                source = new ArrayList<Student>();
                System.out.println("No data!");
            } else {
                System.out.println("Data recieved");
            }
            Iterator student = source.iterator();
            while (student.hasNext()) {
                Student s = (Student)student.next();
                System.out.println(s.getName()+"\t"+s.getPassword()+"\t"+s.getBalance());
                }
        } else {
            source = new ArrayList<Student>();
            System.out.println("New file!");
        }
        context.setAttribute("data", source);
        System.out.println("BinaryFile SevletContextListener started");
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        ServletContext context = sce.getServletContext();
        List source=(List)context.getAttribute("data");
        try {
            System.out.println("Printing data!");
            Iterator student = source.iterator();
            while (student.hasNext()) {
                Student s = (Student)student.next();
                System.out.println(s.getName()+"\t"+s.getPassword()+"\t"+s.getBalance());
            }
            File outputFile = new File(context.getRealPath("/")+"WEB-INF/Student.dat");
            ObjectOutputStream objectOutputFile = new ObjectOutputStream(new FileOutputStream(outputFile));
            objectOutputFile.writeObject(source);
            System.out.println("DONE");
            objectOutputFile.close();
        } catch (Exception e){
            System.out.println("Outpur error!");
        }
        System.out.println("ServletContextListener destroyed");
    }
}