Saving a Serialized class into a MySQL Database.

haduart — Tue, 29 Jan 2008 13:35:10 +0000

/**
	  * Actualitza l'objecte serialitzat (scorm_structure) de 
	  * l'usuari amb l'identificador indicat.
	  * 
	  * Nota! Fa un update, per tant ha d'existir l'usuari!
	  * 
	  * @param courseStudentName : El nom de la taula en que ho guardem.
	  * @param studentId : L'identificador de l'usuari.(int Type) 
	  * @param object : Retornarà l'UserObjective, caldrà fer un cast.
	  * @return int Type: Retornarà l'identificador del resultset.
	  * @throws Exception : Llança una excepció si hi ha un error.
	  */
	private int writeJavaObject(
			final String courseStudentName,
			final int studentId,
			final Object object) 
	 throws Exception {		
		String sqlUpdateScormStructure =
			"UPDATE " + courseStudentName
			+ " set scorm_structure = ? WHERE student_id = ?";
                /** We already have
                  * private Connection conn = DriverManager.getConnection(url, userName, password);
                  */
		PreparedStatement pstmt =
			conn.prepareStatement(sqlUpdateScormStructure);
		
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		ObjectOutputStream oout = new ObjectOutputStream(baos);
		oout.writeObject(object); //serializing
		    
		// set input parameters
		pstmt.setBytes(1, baos.toByteArray());		    
		pstmt.setInt(2, studentId);
		pstmt.executeUpdate();

		// get the generated key for the id
		ResultSet rs = pstmt.getGeneratedKeys();
		int id = -1;
		if (rs.next()) {
			id = rs.getInt(1);
		}
		
		rs.close();
		pstmt.close();
		return id;
	}

[Blob] [Java] [MySQL]

Loading a dinamic Library

haduart — Mon, 28 Jan 2008 16:38:34 +0000

/**
* In the D:/LoadLibrary we must have .class and the same interface (TestString) with the same pacakge as the 
* main program. 
*/
URL urlToJar = new URL("file://D:/LoadLibrary/");
URLClassLoader cl = new URLClassLoader(new URL[] { urlToJar });
		
System.out.println("loading...");
Class c2 = cl.loadClass("TestHelloWorld");
System.out.println("loaded!");
Object nouObject = c2.newInstance();

TestString ts = (TestString) cons.newInstance(args);
/**
* Now we can use the "ts" object as a normal TestString interface. No matter which is the implementation that is begin it.
*/
System.out.println("S1: " + ts.printS1());
System.out.println("S2: " + ts.printS2());

[Dinamic] [Java] [Library]

Posteet: haduart

Saving a Serialized class into a MySQL Database.

Loading a dinamic Library