Where to write Validation

[Rajendra Prakash]

I am new to web Application development. In jsp page am entering name PRAKASH ,
but the name already exists in database means where i have to write validations for this criteria.

[akhter wahab]

write in the DAO that is responsible for database communication...can write in the same jsp page to .. its up to your application architecture

[Rajendra Prakash]

How to write in the same jsp page.

[akhter wahab]

again on your bussiness logic....... send the name parameter to the database get the value of the in the jsp page as boolean if it exists then get true ..if get true than show that it is already exists

[Campbell Ritchie]

Moving to a more appropriate forum.

[Rajendra Prakash]

I understand the logic which you said. I am new to development.
Can you say from which file you send request to database ( )
and which file you retrieve data

[Rajendra Prakash]

suppose am using jsp,servlet , struts , hibernate. From which file i send request to DB.
In which file i request data from DB

[akhter wahab]

well in more appropriate way jsp use only for geting info and receive perameter in the servlets and a simple java class is used for database connectivity and methods make the object of java class in servlet and send response back to jsp page

[David Newton]

Rajendra Prakash wrote:suppose am using jsp,servlet , struts , hibernate. From which file i send request to DB.
In which file i request data from DB

A service class inside the action or the action form--it kind of depends.

[Rajendra Prakash]

previously i used following code to validate username and password.
But now i am using struts , how can i get username and pwd instead of reques.getParameter()
I know there is getUsername() and getPassword() in ActionForm.
My question is , i need single line how to assign getUsername() and getPassword() to string variable.

<%@ page language="java" import="java.sql.*" pageEncoding="UTF-8"%>
<%
String username=(String) request.getParameter("username ");
String password=(String) request.getParameter("password ");
Class.forName("com.mysql.jdbc.Driver");
String url="jdbc:mysql://localhost:3306/dbName?user=root&password=acc";// JDBC URL
Connection conn=DriverManager.getConnection(url);
Statement stmt=conn.createStatement();
String sql="SELECT * FROM member WHERE username='"+username+"' and password='"+password+"'";
ResultSet rs=stmt.executeQuery(sql);
boolean isCheck=false;
if(rs.next()){
isCheck=true;
}

[Seetharaman Venkatasamy]

  String username=(String) request.getParameter("username ");   

there is a redundant casting. I think it is not a struts application,you have to get username in service method only like above.

I do the form(user fields) validation using methods in servlet. and business validation in DAO

[Rajendra Prakash]

Its not struts ok. Give me that single line, how to get username and pwd in service method

[Seetharaman Venkatasamy]

Rajendra Prakash wrote:Its not struts ok. Give me that single line, how to get username and pwd in service method

what do you mean by single line?
this is the way :

    
String username = request.getParameter("username");   
String password = request.getParameter("password"); 

[Rajendra Prakash]

How to do the same in struts.If you use struts means there will be ActionForm(getUsername () , getPwd() )
which eliminates request.getParameter() method.

String username = x.getUsername()
String password = xgetPassord()

From the above code what is " x ".

[Seetharaman Venkatasamy]

the x --> scope of the actionform in struts. if you want struts then switch to struts framework