Validating username and password in servlet Vdeo datng cam 2
If you would like to declare method then you can use JSP declarative such as sorry for bordering you guys my code connect to the database perfectly, but it is not validating the input from the login form rather with or without username/password,the jsp will still forward to the welcome page.
can any of you write a perfect validating code for me because i can't think any more.
The responsibility of the data to be sent (like valid or invalid etc.) to the client is taken care by Http Servlet Response. Content Type("text/html"); set Content Type(String) is a method of Servlet Response inherited by Http Servlet Response and its job is sending the information to client’s browser of how the response sent by the servlet is to be formatted. That is, the data sent to the client is either in text format (as in ("VALID")) or HTML format (as in (INVALID)). This is more called as setting the MIME (Multipurpose Internet Mail Extension) type. get Parameter(String) method of Servlet Request (inherited by Http Servlet Request) takes a string parameter and returns a string.
The programmer job is simply to pass the response messages (to be reached to client) to Http Servlet Response and actual sending is taken care by the container. The parameter is nothing but the field name (here, t1) and the returned string value is what user entered in field t1.
After going through the introduction and architecture of servlets, let us write a simple Login Validation program. Client Program – User Being the first Servlet Example, let us have a detailed discussion on each line. import javax.servlet.*; The above package is imported for the sake of class Servlet Exception. import javax.*; The above package is imported for the abstract class Http Servlet and interfaces Http Servlet Request and Http Servlet Response. import *; package is needed for Print Writer and IOException. public class Validation extends Http Servlet To write a servlet, it is required to extend the abstract class Http Servlet, like Applet is required to extend to write an applet. From the above hierarchy, it can be understood that to develop a servlet there are three styles.
(2)In JSP, Instead of finding whether there is any row exist with userid and pwd, using the userid, get the password.
b) Http Servlet Response interface The second parameter can be either of Servlet Response or its sub-interface Http Servlet Response. println() is a method of Print Writer used to attach a message, here, as a string parameter.
We use Servlet Response as parameter when we extend Generic Servlet and Http Servlet Response when Http Servlet is extended. This string message (here, VALID OR INVALID) is ultimately sent to client by the Http Servlet Response. String str1 = Parameter("t1"); We know the data sent by client (known as request) finally reaches Http Servlet Request.
Then compare with the password that you got from html page and the password from the query If the above is not working out, I recommend you to keep the presentation(view) in JSP, validation in a servlet.
Also keep the dbase connections in a separate class.