I'm looking for how to use ObjectInputStream for a university project.
I found a lot of things but I don't know why I can't succeed with it. Worst, I have more and more warnings.
Here are my three classes:
public class Contact implements Comparable<Contact>
{
private String nom;
private String prenom;
private int numTel;
private static int nbContacts;
private int numContact;
public Contact(String nom, int tel) //Constructeur nom et numero
{
System.out.println(this.numTel);
this.numTel = tel;
System.out.println(this.numTel);
this.nom = nom;
this.numContact=++nbContacts;
}
public Contact(String nom) //Constructeur Nom
{
this.nom = nom;
this.numContact=++nbContacts;
}
public Contact(String nom, String prenom, int tel) //Constructeur Nom, prenom, numero
{
this.numTel = tel;
this.nom = nom;
this.prenom = prenom;
this.numContact=++nbContacts;
}
public String getNom()
{
return this.nom;
}
public String getPrenom()
{
return this.prenom;
}
public int getTelephone()
{
return this.numTel;
}
public int getNumContact()
{
return this.numContact;
}
public void setNom(String nom)
{
this.nom = nom;
}
public void setNumTelephone(int num)
{
this.numTel = num;
}
public boolean equals(Contact contact)
{
if(!this.nom.equals(contact.getNom()))
{
return false;
}
if(this.numTel!=contact.getTelephone())
{
return false;
}
return true;
}
public int compareTo(Contact contact)
{
return (Integer.valueOf(this.nom) - Integer.valueOf(contact.getNom()));
}
public String toString()
{
String s = this.numContact + ") ";
s+= String.format ( "%-10s", "NOM : ") + this.nom;
if(this.prenom != null)
{
s+=" | " + String.format ( "%-10s", "PRENOM : " ) + this.prenom ;
}
if(this.numTel != 0)
{
s+= " : " + this.numTel;
}
s += "\n";
System.out.println(this.nom);
return s;
}
}
next
import java.util.ArrayList;
import java.util.List;
import java.io.*;
import java.util.Collections;
public class Repertoire
{
private ArrayList<Contact>alContact;
public Repertoire()
{
alContact = new ArrayList<Contact>();
this.getData();
}
public String toString()
{
String s = "";
for ( int cpt = 0; cpt < alContact.size(); cpt++ )
{
s += alContact.get(cpt).toString() + "\n";
}
return s;
}
public void addContact(String nom, int tel) //Constructeur nom et numero
{
alContact.add(new Contact(nom, tel));
this.sauvegarder();
}
public void addContact(String nom) //Constructeur Nom
{
alContact.add(new Contact(nom));
this.sauvegarder();
}
public void addContact(String nom, String prenom, int tel) //Constructeur Nom, prenom, numero
{
alContact.add(new Contact(nom, prenom, tel));
this.sauvegarder();
}
// Permet d'enregistrer dans un fichier .dat les éléments du répertoire
private void sauvegarder()
{
try
{
ObjectOutputStream out = new ObjectOutputStream ( new FileOutputStream ("Rep.txt") );
out.writeObject ( alContact );
}
catch ( Exception e ) {}
}
public void getData()
{
FileInputStream fis = null;
ObjectInputStream in = null;
try
{
fis = new FileInputStream("~/Rep.txt");
in = new ObjectInputStream(fis);
alContact = (ArrayList) in.readObject();
in.close();
}
catch (IOException ex)
{
System.out.println("Bordel");
}
catch (ClassNotFoundException ex)
{
System.out.println("Gros Bordel");
}
}
// Permet de recuperer les donnée dans un fichier txt
private boolean charger()
{
try
{
System.out.println("Dedans");
ObjectInputStream in = new ObjectInputStream ( new FileInputStream ("Rep.txt"));
System.out.println("Dedans");
alContact = (ArrayList<Contact>) in.readObject();
System.out.println("Dedans");
}
catch ( Exception e )
{
System.out.println("Pas de fichier");
return false;
}
Collections.sort (alContact);
return true;
}
}
And just a Test
public class Test
{
public static void main(String[] args)
{
int tel;
Repertoire rep = new Repertoire();
/*System.out.println("Entrez le numero");
tel = Clavier.lire_int();
rep.addContact("José", tel);
*/System.out.println(rep);
}
}
This program is a phone index. I try to save index into a .txt/.dat but when I can't put it into the program. I hope it's understandable.
Your Contact class must implement Serializable in order to be serializable to save/read to/from InputObjectStream/OutputObjectStream.
From ObjectInputStream documentation:
Classes control how they are serialized by implementing either the java.io.Serializable or java.io.Externalizable interfaces
Implementing the Serializable interface allows object serialization to save and restore the entire state of the object and it allows classes to evolve between the time the stream is written and the time it is read. It automatically traverses references between objects, saving and restoring entire graphs.
Note that when you run the Repertoire#getData in your program and your file is empty, you won't load any data at all. So, it would be better to first save some data in it. You can do this to add some data:
public void setStartData() {
Contact contact = new Contact("Luiggi", "Mendoza", 12345);
List<Contact> lstContact = new ArrayList<Contact>();
lstContact.add(contact);
ObjectOutputStream out = null;
try {
out = new ObjectOutputStream(new FileOutputStream("Rep.txt"));
out.writeObject(lstContact);
out.flush();
} catch (IOException e) {
System.out.println("Error while saving data.");
e.printStackTrace(System.out);
} finally {
if (out != null) {
out.close();
}
}
}
Additional advices:
static fields won't be serialized when saving data on file.Serializable class should be serializable as well. This means, if you have an object instance inside it, its class must implement the Serializable interface.transient modifier.