Persistance d'objets avec jdbc

Voila j'ai une classe Gestion, avec dedans deux ArrayList qui contiennent des objets, j'aimerais faire persister ces arraylist à travers une base de données MySql

Donc j'ai ma classe Gestion :

Code:

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package Gestion;
 
import java.util.*;
 
 
import java.io.Serializable;
public class Gestion implements Serializable{
 
	//Les Réservations
 
	private ArrayList lesReservations= new ArrayList();
 
	public void addReservation(String code, GregorianCalendar dateDemande, int dureeOccupation,
			GregorianCalendar dateDebut, Personne unePersonne, int nbPersonnes, Emplacement unEmplacement){
		Reservation r = new Reservation (code, dateDemande, dureeOccupation, dateDebut, unePersonne, nbPersonnes, unEmplacement );
		lesReservations.add(r);
	}
	public ArrayList getLesReservations() {
		return this.lesReservations;
	}
	public Reservation getReservation(String numero){
		Reservation res = null;
		for (int i = 0; i<lesReservations.size();i++){
			if ( ((Reservation)lesReservations.get(i)).getCode().equals(numero)){
		res = ((Reservation)lesReservations.get(i));}}
		return res;
	}
 
	public ArrayList retrouveReserveClient(String codeClient){
		ArrayList sesReservations = new ArrayList();
		for (int i = 0; i<lesReservations.size();i++)
		{
		if (((Reservation)lesReservations.get(i)).getUnePersonne().getCodeClient().equals(codeClient))
		{
		sesReservations.add(lesReservations.get(i));
		}}	
	return sesReservations;	
	}
 
	public int nombreReservations(){
		return lesReservations.size();
	}
 
	public float surfaceTotale(){
		float resultat = 0;
		for (int i = 0; i < lesEmplacements.size(); i++){
			resultat = resultat + ((Emplacement)lesEmplacements.get(i)).getSurface();
		}
		return resultat;
	}
 
	//Les Emplacements
 
	private ArrayList lesEmplacements = new ArrayList();
 
	public ArrayList getLesEmplacements(){
		return this.lesEmplacements;}
 
	public Emplacement getEmplacement(String numero){
		Emplacement emp = null;
		for (int i = 0; i<lesEmplacements.size();i++){
			if ( ((Emplacement)lesEmplacements.get(i)).getNumero().equals(numero)){
		emp = ((Emplacement)lesEmplacements.get(i));}}
		return emp;
	}
	public void addRempli(String numero, boolean ombrage, int longueur, int largeur, int taxePersonne,String libelle, int nbChambres, int nbPieces, int presenceWc, boolean terrasse){
		Rempli r = new Rempli (numero, ombrage, longueur, largeur, taxePersonne, libelle, nbChambres, nbPieces, presenceWc, terrasse);
		lesEmplacements.add(r);}
	public void addVide(String numero, boolean ombrage, int longueur, int largeur, int taxePersonne, boolean electricite){
		Vide v = new Vide (numero, ombrage, longueur, largeur, taxePersonne, electricite);
		lesEmplacements.add(v);}
 
 
	public ArrayList retrouveReserveEmp(String codeEmp){
		ArrayList sesReservations = new ArrayList();
		for (int i = 0; i<lesReservations.size();i++)
		{
		if (((Reservation)lesReservations.get(i)).getUnEmplacement().getNumero().equals(codeEmp))
		{
		sesReservations.add(lesReservations.get(i));	
		}	
		}	
	return sesReservations;	
	}
 
	//Calculer les dates
 
 
	//Ressortir les dates disponibles pour un emplacement donné
 
 
 
 
	//
	public boolean emplacementsDispo(GregorianCalendar dateDepart){
        boolean b;
        b = true;
 
 
        for (int i = 0; i < lesReservations.size();i++){
        if( ((Reservation)lesReservations.get(i)).getDateDebut().before(dateDepart) && ((Reservation)lesReservations.get(i)).calculeDateFin().after(dateDepart)){
            b = false;
        }}
        return b;
    }
 
 
}

Et la classe qui permet de sérialiser et d'envoyer vers la bdd :

Code:

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package	Gestion;
/**SQL to create MySQL Table For Object Storing**/
 
/*CREATE TABLE javaobjects (
 objectid INT AUTO_INCREMENT,
 object_name varchar(100),
 object_value BLOB,
 primary key (objectid));
 */
 
import java.io.ByteArrayInputStream;
import java.io.ObjectInputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
 
public class SerializeJavaObjects_MySQL {
	static final String SQL_TO_WRITE_OBJECT = "INSERT INTO JAVAOBJECTS(OBJECT_NAME, OBJECT_VALUE) VALUES (?, ?)";
	static final String SQL_TO_READ_OBJECT = "SELECT OBJECT_VALUE FROM JAVAOBJECTS WHERE OBJECTID = ?";
 
	static String driver = "com.mysql.jdbc.Driver";
	static String url = "jdbc:mysql://localhost/Ecamping";
	static String username = "client";
	static String password = "client";
 
	/**
         * This class will create and return a database connection.
         */
	public static Connection getConnection() throws Exception {
		Class.forName(driver);
		Connection conn = DriverManager.getConnection(url, username, password);
		return conn;
	}
 
	/**
         * This method will write a java object
         * to the database
         * Parameters: connection object and object to be serialized
         */
	public static long writeJavaObject(Connection conn, Object object)
			throws Exception {
		String className = object.getClass().getName();
		PreparedStatement pstmt = conn.prepareStatement(SQL_TO_WRITE_OBJECT);
		pstmt.setString(1, className);
		pstmt.setObject(2, object);
		pstmt.executeUpdate();
		ResultSet rs = pstmt.getGeneratedKeys();
		int id = -1;
		if (rs.next()) {
			id = rs.getInt(1);
		}
		rs.close();
		pstmt.close();
		System.out.println("Serialization Successful."+
						   "Serialized Class: "+ className);
		return id;
	}
 
	/**
         * This class will de-serialize a java object from the database
         */
	public static Object readJavaObject(Connection conn, long id)
			throws Exception {
		PreparedStatement pstmt = conn.prepareStatement(SQL_TO_READ_OBJECT);
		pstmt.setLong(1, id);
		ResultSet rs = pstmt.executeQuery();
		rs.next();
		byte[] buf = rs.getBytes("object_value");
		ObjectInputStream objectIn = null;
		if (buf != null)
			objectIn = new ObjectInputStream(new ByteArrayInputStream(buf));
		Object object = objectIn.readObject();
		String className = object.getClass().getName();
		rs.close();
		pstmt.close();
		System.out.println("Deserialization Successful."+
							"\nDeserialized Class: "+ className);
		return object;
	}
 
	/**
         * Testing the serialization and deserialization feature.
         */
 
	public static void main(String args[]) throws Exception {
		Connection conn = null;
		try {
			/**Creating DB Connection**/
			conn = getConnection();
			conn.setAutoCommit(false);
			/**Creating Test object to Serialize**/
			Gestion obj = new Gestion();
			/**
                         * Serializing the object and getting the database id,
                         * which is nothing but an autogenerated key
                         */
			long objectID = writeJavaObject(conn, obj);
			conn.commit();
			System.out.println("Serialized object ID" + objectID);
			/**
                         * Reading the object from database.
                         * This object is just serialized into database above.
                         */
 
			Gestion objFromDatabase = (Gestion) readJavaObject(
					conn, objectID);
			System.out.println("After Deserialization:");
			System.out.println("Object Value: " + objFromDatabase);
			System.out.println("Class: " + objFromDatabase.getClass().getName());
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			/**Closing the database connection**/
			conn.close();
		}
	}
}

Cependant quand je lance sous eclipse ca me met :

Code:

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java.sql.SQLException: Generated keys not requested. You need to specify Statement.RETURN_GENERATED_KEYS to Statement.executeUpdate() or Connection.prepareStatement().
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926)
	at com.mysql.jdbc.StatementImpl.getGeneratedKeys(StatementImpl.java:1856)
	at Gestion.SerializeJavaObjects_MySQL.writeJavaObject(SerializeJavaObjects_MySQL.java:51)
	at Gestion.SerializeJavaObjects_MySQL.main(SerializeJavaObjects_MySQL.java:101)

Bonjour,

l'erreur parait pourtant assez claire, tu cherches a inserer en base de donnees dans une table contenant une cle primaire que tu ne mets pas dans ton insert (OBJECTID), le compilateur te demande donc d'explication mettre que tu veux generer les cles :

Code:

java.sql.SQLException: Generated keys not requested. You need to specify Statement.RETURN_GENERATED_KEYS to Statement.executeUpdate() or Connection.prepareStatement().

Normalement, cela est faisable en rajoutant cela dans un prepareStatement :

Code:

PreparedStatement psTxnType = con.prepareStatement(query,Statement.RETURN_GENERATED_KEYS);

Merci de ton aide, je met ou le code que tu m'as passé ?

Dans ta methode writeDataObject, tu as la ligne :

Code:

PreparedStatement pstmt = conn.prepareStatement(SQL_TO_WRITE_OBJECT);

tu ajoutes donc le deuxieme parametre pour avoir :

Code:

PreparedStatement pstmt = conn.prepareStatement(,Statement.RETURN_GENERATED_KEYS);

Merci de ton aide, tout est ok!