Dynamic images in jsp

[jagmeet singh]

Hello
I want to dynamically out image. The page queries the database. Code is here

<%
String uname=(String)request.getParameter("user");
        
int n=cn.executeUpdate("Delete from signup where username='"+uname+"'");

cn.executeUpdate("Delete from resume where fname='"+uname+"'");
if (n>0)
  {
    out.println("<h4 align=center> User Deleted !<br>");
    out.println(" <img align=\"CENTER\" src=\"image/pics/success.jpg>\" ");
  }
else
   
 {
  out.println("<h4 align=center>Oops! User not deleted.");
 out.println(" <img align=\"CENTER\" src=\"image/pics/fail.jpg>\" "); 
%>
        <a href="admin1.jsp">Back to admin</a>
    </body>

Error: the pictures are not added when the page returns "User Deleted"

[Bear Bibeault]

Please be sure to use code tags when posting code to the forums. Unformatted or unindented code is extremely hard to read and many people that might be able to help you will just move along to posts that are easier to read. Please click this link ⇒ UseCodeTags ⇐ for more information.

Properly indented and formatted code greatly increases the probability that your question will get quicker, better answers.

[jagmeet singh]

Hi Bear Bibeault
I have edited my topic. Thanks for guidance!

Bear Bibeault wrote:Please be sure to use code tags when posting code to the forums. Unformatted or unindented code is extremely hard to read and many people that might be able to help you will just move along to posts that are easier to read. Please click this link ⇒ UseCodeTags ⇐ for more information.

Properly indented and formatted code greatly increases the probability that your question will get quicker, better answers.

[Bear Bibeault]

But you didn't add the code tags. That will preserve the formatting.

Also, why are you still using scriptlets in JSPs? They have been discredited for over 8 years now. You should really be using JSTL and EL by now. And that would make all of this much much easier.

[jagmeet singh]

Actually this was a ready made project i am editing. I was persuing OCP training. And in india , thouse scriplets are still being taught.
I have no choice.
I didnt visited the use tag form. now i have. next time i will use these tags.

[Bear Bibeault]

Understood. As long as your are aware that this is old technology that should not be used in new code...

Please add code tags as suggested. It will make the code more readable. Also, what is the specific error message that you are getting? Please include it in code tags as well to preserve the formatting.

[jagmeet singh]

edited the code with error.

[David Newton]

Look where the quotes are on the fail image tag.

[Paul Clapham]

This may also not be relevant, but using a query which is built from a string is liable to have problems. If the user's name contained an apostrophe (which some people's names do) then the SQL query will be malformed and an exception will be thrown. Building a query that way also exposes your system to SQL injection attacks. A better-designed system wouldn't do that; it would use PreparedStatement objects for queries with parameters.

[David Newton]

See also: Little Bobby Tables.

[Paul Clapham]

David Newton wrote:Look where the quotes are on the fail image tag.

It took me a long time to see that, even when it was pointed out. The quotes are in the wrong place in the success image tag too. That's what you get when you have JSP scriptlets generating HTML; too much quote-escaping, hard to read.

[Bear Bibeault]

David Newton wrote:Look where the quotes are on the fail image tag.

Building up HTML inside a Java string, inside a JSP, is pretty much a FAIL in and of itself. The whole purpose of a JSP is so that HTML markup can be entered directly as template text.

You might want to refactor to remove the HTML from strings where silly syntax errors are hard to avoid.

[David Newton]

Bear Bibeault wrote:FAIL

out.println("<img src=\"image/pics/fail.jpg alt=\"JSP: ur doing it wrong>\" ");   

[jagmeet singh]

I got it:
1. The code is buggy, prone to sql injections.
2. It's using old tech

But i have no choice guys. Need to submit the project. I will give live demo and through it away.
the code did not worked :banghead: :--

David Newton wrote:

Bear Bibeault wrote:FAIL

out.println("<img src=\"image/pics/fail.jpg alt=\"JSP: ur doing it wrong>\" ");   

[David Newton]

Really? You tried my code?!

In any case: FIX THE QUOTES.

[jagmeet singh]

 out.println("<h4 align=center>Oops! User not deleted.");
 out.println("<img src=image/pics/deleteuser.png> ");

Earlier net beans was not even allowing me to write the same code. Now its working.
Thanks DAVID NEWTON.

[Paul Clapham]

jagmeet singh wrote:Earlier net beans was not even allowing me to write the same code. Now its working.
Thanks DAVID NEWTON.

But now we can add "Generates malformed HTML" to its list of sins. (Although probably it was already doing that too, right?)

To put the attribute value quotes in the right place:

out.println("<h4 align=center>Oops! User not deleted.");
out.println("<img src=\"image/pics/deleteuser.png\"> ");