Is my javaBean a javaBean?

[Parka Teoh]

I'm sorry if I posted this in the wrong forum.

Here's my problem...
I have a javaBean that writes stuff to the database to be saved.
It works fine when I use a testing Class to invoke the bean's method to write some dummy variables.

When I deployed it on a JSP page, I received the following error.

"org.apache.jasper.JasperException: /checkout.jsp(4,0) The value for the useBean class attribute limited.InsertDataBean is invalid.
"

I should think my bean met the bean requirements. But I can't find out what's wrong. Any help would be really really really great..

Here's my insertDataBean code

package limited;
 
import java.sql.*;
 
public class InsertDataBean{
 
private String driver = "sun.jdbc.odbc.JdbcOdbcDriver";
private String url = "jdbc   :-o	   dbc:LimitedVideoDSN";
private String username = ""; // No username/password required
private String password = ""; // for desktop access to MS Access.
private Statement statement = null;
private Connection connection = null;
private GetOrderIDBean idBean = new GetOrderIDBean();
 
// Create an empty constructor
InsertDataBean(){};
 
//public static void main(String[] args) {
public void setOrderTable(String orderName, String address, String creditCardNumber){
 
try {
 
// Invoke the GetOrderIDBean method to get the last orderID
idBean.readLastOrderID();
// Load database driver if it's not already loaded.
Class.forName(driver);
 
// Establish network connection to database.
connection = DriverManager.getConnection(url, username, password);
 
System.out.println("The id added to product: " + idBean.getUniqueOrderID() + "\n");
 
// Create a statement for executing queries. Parameters come from JSP
statement = connection.createStatement();
 
String order = "INSERT INTO [order] VALUES (" + idBean.getUniqueOrderID()
+ ", '" + ProcessBean.orderName + "', '"
+ ProcessBean.orderAddress + "', '"
+ ProcessBean.orderCreditCardNumber + "');";
 
 
// Run the SQL statements to insert the details from checkout page
 
statement.executeUpdate(order);
 
//setOrderDetails(ProcessBean.pdtID, ProcessBean.pdtQuantity);
 
// Close connection of database
connection.close();
 
} catch(ClassNotFoundException cnfe) {
System.err.println("Error loading driver: " + cnfe);
} catch(SQLException sqle) {
System.out.println("set Order Table Error ");
System.err.println("Error with connection: " + sqle);
}
}
 
 
public void setOrderDetails(int pdtID, int pdtQuantity){
try {
 
// Invoke the GetOrderIDBean method to get the last orderID
//idBean.getLastOrderID();
 
// Load database driver if it's not already loaded.
Class.forName(driver);
 
//idBean.getLastOrderID();
connection = DriverManager.getConnection(url, username, password);
 
Statement statement = connection.createStatement();
 
 
System.out.println("pdt ID: " + pdtID +
" uniqueOrderID: " + idBean.getUniqueOrderID()
+ " pdt quantity: " + pdtQuantity + "\n");
// Create a statement for executing queries. Parameters come from CartBean, JSP
String orderDetails = "INSERT INTO [order details] VALUES (" + pdtID
+ ", " + idBean.getUniqueOrderID() + ", "
+ pdtQuantity + ");";
 
// Run the SQL statements to insert the details from checkout page
statement.executeUpdate(orderDetails);
 
// Close connection of database
connection.close();
} catch(ClassNotFoundException cnfe) {
System.err.println("Error loading driver: " + cnfe);
}  catch(SQLException sqle) {
System.out.println("InsertDataBean: Set Order Details error ");
System.err.println("Error with connection: " + sqle);
}
}
 
}

[Ray Stojonic]

There error you received has to do with the JSP syntax you used to import the bean, not a problem with the bean itself (Jasper's job is to turn JSP into java code, not to make sure you followed good programming practices while designing your bean)

[Parka Teoh]

Hi.

I have the following tags in my JSP.

<jsp:useBean id="cart" scope="session" class="limited.CartBean" />
<jsp:useBean id="idBean" scope="page" class="limited.GetOrderIDBean" />
<jsp:useBean id="databean" scope="page" class="limited.InsertDataBean" />

Only the third failed to compiled.



Nothing's looking wrong.....or is there...

[Ray Stojonic]

On further inspection, your default constructor isn't public and must be to be used with the useBean tag.

[Parka Teoh]

Hmmmm...

When I included the public infront of the empty constructor, it still couldn't work.

But when I deleted the constructor away, it's able to work again.

Oh my!! It works now!