Form processing in JSP with array elements

Question

Is there a class or object in JSP (No beans JSP only) I can call to reference a HTML Form and its elements. I want to perform database insert using data from an dynamically generated form. The form will generate N rows (based on parameters pass from the previous page) and I want to perform N inserts into a database based on the data from the N rows.
I've done something similar in javascript, using the document.form[0].elements[j]value to pass data within a for loop running form[0].elements.length times.
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Thanks

Answer 1

I may not understand your question correctly. I assume that you already have the code to generate the html form, you just need code to access entered values once the form is submitted right?
One way you can do this is to use the request.getParameterNames method. This would be easiest if there is only one entry field per row. For instance if you have N text boxes on your page, and the form is submitted, you can use request.getParameterNames to get an iterator of all the names of the text boxes. You can use this iterator to get all the values. Notice that the name of the fields here is irrelevant.
Enumeration names = request.getParameterNames();
while (names.hasNext()) {
String curVal = (String) names.nextValue();
//--- insert record for curVal
If there are multiple entry fields for each row, its slightly more difficult. I can recommend one approach. Name all the fields with a naming scheme.
The first field in the first row would be 1Field1, the second field in the first row would be 1Field2, etc. The first field in the second row would be 2Field1, the second field in the second row would be 2Field2, etc. Then its just a matter of using two for loops in your next JSP to iterate over all the records and fields. You might make it easy for yourself by writing the number of rows in a hidden field on the form. The insertion might look like this:
int numRows = Integer.parseInt(request.getParameter("numRows"));
for (int i = 0; i < numRows; i++) {
String sql = "some sql...";
for (int j = 0; j < fieldNum; j++) {
sql += request.getParameter(i + "Field" + j);
//-- perform insert
My sql generation is horridly abbreviated but hopefully you get the idea.
I am sure there are other ways to do this, maybe this will work or get you thinking.