Issue
I am trying to make a basic shop-billing JSP project. now when i type random product quantity with checkbox it giving error like below image. but when i checked-value with serial wise, it is not giving the error, it giving me the result what i desiring. I have also check it is empty or not. but can't able to get out of this error. how can i get rid out of it?
Code:
<%--
Document : order
Created on : Jun 15, 2019, 3:11:06 PM
Author : Riddhi
--%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@page import="java.sql.*" %>
<!DOCTYPE html>
<html lang="en">
<%@ include file="header.jsp" %>
<h2 class="text-center"> ShopBilling </h2>
<p><br/></p>
<%
String Host = "jdbc:mysql://localhost:3306/shopbilling";
Connection connection = null;
Statement statement = null;
ResultSet rs = null;
PreparedStatement ps=null;
Class.forName("com.mysql.jdbc.Driver").newInstance();
connection = DriverManager.getConnection(Host, "root", "");
StringBuilder sb = new StringBuilder();
%>
<div class="row justify-content-center">
<div class="col-md-6">
<div class="row">
<div class="col-md-6"><h3>Product Details</h3></div>
<div class="col-md-6 text-right">
<a href="products.jsp" class="btn btn-info">Back to Home</a>
</div>
</div>
<p></p>
<form action="" method="post">
<%
String products[] = request.getParameterValues("products");
String items[] = request.getParameterValues("item_no");
int sum=0;
if (products!= null && items!= null && products.length != 0 && items.length != 0) {
for (int i = 0; i < products.length; i++) {
%> <%
statement = connection.createStatement();
String u=request.getParameter("u");
int num=Integer.parseInt(products[i]);
String Data = "select * from products_tbl where id='"+num+"'";
rs = statement.executeQuery(Data);
while (rs.next()) {
%>
<input type="hidden" name="id" value='<%=rs.getString("id")%>'/>
<div class="form-group">
<label for="product_name">Product Name: <%=rs.getString("product_name")%></label>
<input type="hidden" class="form-control" id="product_name" name="product_name" value='<%=rs.getString("product_name")%>'>
</div>
<div class="form-group">
<label for="product_price">Product Single Price: <%=rs.getString("product_price")%></label>
<input type="hidden" class="form-control" id="product_price" name="product_price" value='<%=rs.getString("product_price")%>'>
</div>
<div class="form-group">
<label for="product_name">Item Quantity: <% out.println(items[i]); %></label>
<input type="hidden" class="form-control" id="item_no" name="item_no" value='items[j]'>
</div>
<div class="form-group">
<label for="product_name">Product Total Price: <%
int num1=Integer.parseInt(items[i]);
int propri=Integer.parseInt(rs.getString("product_price"));
out.println(num1 * propri); int gtotal= num1 * propri; %></label>
<input type="hidden" class="form-control" id="item_no" name="item_no" value='items[j]'>
</div>
<hr>
<% sum= sum + gtotal; %>
<%
}
}
}
%>
<div class="form-group">
<label for="product_name">Grand Total: <%
out.println(sum); %></label>
<input type="hidden" class="form-control" id="item_no" name="item_no" value='items[j]'>
</div>
<button type="print" onclick="window.print();" class="btn btn-warning">Print</button>
</form>
</div>
</div>
<%@ include file="footer.jsp" %>
</html>
Solution
I think the problem in your code is with <input type="text" name="item_no" />
because every row in your above code has checkbox
, when you submit your form only selected checkbox
is passed , but all <input type="text" name="item_no" />
is passed even the null
where you didn't give any value , so when you iterate you get null value
with that as well .Now ,to solve this do like below :
//give value to your check-box i.e id of that row
<input type="checkbox" name="products" value ='<%=rs.getString("id")%>' />
//pass that id with your input type i.e item_no_1 ..etc
<input type="text" name='item_no_<%=rs.getString("id")%>' />
And then to get only particular value of Product Quantity
where you have selected Checkbox
do like below :
String products[] = request.getParameterValues("products");
if (products!= null && items!= null && products.length != 0 && items.length != 0) {
for (int i = 0; i < products.length; i++) {
//your code
<div class="form-group">
<label for="product_name">Product Total Price: <%
//getting item value of that selected checkbox
int item_no=Integer.parseInt(request.getParameter("item_no_" + products[i]));
int propri=Integer.parseInt(rs.getString("product_price"));
out.println(num1 * propri); int gtotal= num1 * propri; %></label>
<input type="hidden" class="form-control" id="item_no" name="item_no" value='items[j]'>
</div>
Answered By - Swati