Could you help me about c:forEach JSTL tag!

Question

hi everybody!
Well I'm having a trouble when I use <jsp:forEach> tag to write the elements of object from a ArraylList:
that is the object I store in the data froom the bank to be shown:
package teste;
public class Detalhes {
    private String titulo;
    private String autor;
    private Double preco;
    private int codigo;
    public Detalhes(String titulo, String autor, Double preco, int codigo) {
        this.titulo = titulo;
        this.autor = autor;
        this.preco = preco;
        this.codigo = codigo;
    public String getTitulo(){
        return titulo;
    public String getAutor(){
        return autor;
    public Double getPreco(){
        return preco;
    public int getCodigo(){
        return codigo;
}and that is the class where I get the data from the database, store it in a object (Detalhes) and get the arrayList (list);
package teste;
public class Data {
    Connection con;
    Detalhes detalhes;
    ArrayList list;
    int codigo;
    public Data()throws Exception {       
        try {
            Class.forName("org.gjt.mm.mysql.Driver");
            con = DriverManager.getConnection("jdbc:mysql://127.0.0.1/Loja?user=root&password=131283");            
        } catch (Exception ex) {
            throw new Exception(" Database not found!!" +
                ex.getMessage());
    public ArrayList getList(){
        try {
            String selectStatement = "select * from produto";
            PreparedStatement prepStmt = con.prepareStatement(selectStatement);
            ResultSet rs = prepStmt.executeQuery();
            while(rs.next()){
                 detalhes = new Detalhes(rs.getString(1), rs.getString(2), rs.getDouble(3), rs.getInt(4));          
                 list.add(detalhes);
            prepStmt.close();
            Collections.sort(list);
        }catch(Exception e){
       return list;
}    the piece of my jsp page is that:
<p><b><h1>Resultado:</h1></b></p><br>
<jsp:useBean id="dataSource" class="teste.Data" scope="page" >
       <jsp:setProperty name="dataSource" property="codigo" value="${param.theCode}"/>          
</jsp:useBean>
<c:forEach var="book" begin="0" items="${dataSource.list}">
    <p><b><h1><font color="red">${book.titulo}<h1></b></p>        
</c:forEach>The result is a blank jsp with no data, have you any advice?
What's wrong? I'll greatfull!!!!

Answer 1

First thing to do is to store the result of the list call to a variable so you don't call the getList method all the time:
<c:set var="bookList" value="${datasource.list}"/>
<c:forEach var="book" items="${bookList}">
Check if anything is added to the List, or if the List is null:
<c:out value=${bookList}"/>
And assume that you are getting an error in your SQL, which you are catching and ignoring when you do:
        }catch(Exception e){
        }            Instead of doing nothing, report the error some-how. Maybe using System.err or System.out (or better yet a real log). Then look at your Server's standard output log to see what may be happening.
If all else fails, don't catch the exceptions - throw them so you get an error in your default server logs or on the web page itself.