Displaying database result in JSP

Question

I have a controller servlet which forward the request to the model servlet.Now when the model gets the results from the database, I am forwarding it to the jsp.I am not sure what to write in the jsp because it need to show a table of customerList.here is part of my model servlet:

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
{
    Connection connection = getDatabaseConnection();
    request.setAttribute("customerList", getCustomerList(connection));
    closeDatabaseConnection(connection);
}

private Vector<Customer> getCustomerList(Connection con)
{
    String sqlStr =
            "SELECT * " +
            "FROM Customer " +
            "ORDER BY Name";
    PreparedStatement stmt = null;
    ResultSet rs = null;
    Vector<Customer> customers = new Vector<Customer>();

    try
    {
        stmt = con.prepareStatement(sqlStr);
        rs = stmt.executeQuery();

        while (rs.next())
        {
            Customer customer = new Customer();
            customer.setId(rs.getInt("Id"));
            customer.setName(rs.getString("Name"));
            customer.setAddress(rs.getString("Address"));

            customers.add(customer);
        }

        rs.close();
        stmt.close();
    }
    catch (SQLException sqle)
    {
        sqle.printStackTrace();
    }
    finally
    {
        return customers;
    }

score 3 · Accepted Answer · edited Jun 20 '20 at 09:12

Use JSTL c:forEach tag. If your servletcontainer doesn't support it (e.g. Tomcat), then you need to drop jstl-1.2.jar in /WEB-INF/lib. Then declare the JSTL core taglib in top of JSP page as per its documentation.

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>

Then you can use any of the JSTL core tags in the JSP. You've put a Vector<Customer> (eek, a legacy class .. rather use List<Customer> customers = new ArrayList<Customer>() instead) in the request scope with the attribute name customerList. So it's available by ${customerList} in EL. Feed it to the items attribute of <c:forEach> and render a <table> accordingly.

<table>
    <c:forEach items="${customerList}" var="customer">
        <tr>
            <td><c:out value="${customer.id}" /></td>
            <td><c:out value="${customer.name}" /></td>
            <td><c:out value="${customer.address}" /></td>
        </tr>
    </c:forEach>
</table>

The <c:out> is by the way not necessary, but useful if it concerns user-controlled input since it prevents XSS attacks.

That said, your JDBC part can be done better. It's still sensitive to resource leaking in case of exceptions.

Displaying database result in JSP

1 Answers1

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