Registering new date in MySQL

When I first register the item in the database it picks up the date it was created and saved in the database, the problem happens when I edit the item in the program and then saved in the database it saves a new date.

Item:

String nome;
int valor;
java.sql.Timestamp datacriado;

public Item(String nome, int valor, java.sql.Timestamp datacriado){
    this.nome = nome;
    this.valor = valor;
    this.datacriado = datacriado;
}
get e set;

Creating new item:

 public void CriarItem(String nome, int valor){
 java.sql.Timestamp data = new java.sql.Timestamp(new java.util.Date().getTime());

 Item novoitem = new Item(nome, valor, data);
 registrarItem(novoitem);
 }

registerItem in database:

    String qy;
public void registrarItem(Item novoitem){
 qy = "INSERT INTO Itens (Nome, Valor, DataCriado) VALUES (?,?,?)";
    try {
        PreparedStatement ps = MySQL.getConn().prepareStatement(qy);
        ps.setString(1, novoitem.getNome());
        ps.setInt(2, novoitem.getValor());
        ps.setTimeStamp(3, novoitem.getDataCriado());
        ps.execute();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

And finally when I edit and save (where I think it's the problem):

public void salvarItem(Item novoitem){
        qy = "UPDATE Itens SET Nome=?, Valor=? WHERE Nome=?";
        if (novoitem != null) {
            try {
                PreparedStatement ps = MySQL.getConn().prepareStatement(qy);
                ps.setString(1, novoitem.getNome());
                ps.setInt(2, novoitem.getValor());
                ps.executeUpdate();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

But if I put in the saveItem to write in the console the date of the item, the correct creation date appears, but after executeUpdate (); it writes a new date in the database (only happens when I edit)