32,996 questions
2
votes
1
answer
126
views
java.lang.ClassCastException: class com.sun.xml.ws.transport.http.servlet.WSServlet cannot be cast to class javax.servlet.Servlet
I took over some "legacy app" which is a SOAP web service based on WSDL files.
As the app was not updated in years and failed to compile with anything but Java 8, I decided, I should try to ...
- 61
0
votes
0
answers
42
views
Displaying search results with JSP and JS not rendering
I'm currenlty working on a hotel management system, and for user management, the user should be able to search the user accounts by their ID, username, or email.
So I'm having trouble with displaying ...
0
votes
1
answer
146
views
Implementing remember-me/stay logged in logic in a Servlet
I would like to implement a remember-me functionality in my very plain servlet-based system. No Spring, No Shiro, nothing. I'm mightily struggling to make it work.
On paper, it seems fairly ...
- 290
0
votes
0
answers
85
views
Jetty 12 cannot load ResourceServlet
I'm running a Java 21 web application with a static part under /webapp path. Until Jetty 11, we used the DefaultServlet for this. Now we get a warning that it is recommended to use the ResourceServlet ...
- 105
0
votes
0
answers
74
views
Application migration to Websphere Liberty
I am migrating an application to Liberty. The application is servlet-based and uses JSP files. I have created Dockerfiles, a Helm chart, and Liberty configuration files such as server.xml. My ...
Advice
0
votes
1
replies
51
views
Share variable/object between multiple servlets
Suppose I want to create a simple counter app with three different servlets: one to read the value (GET), one to increment and one to decrement the value (both POST):
readvalue.java:
@WebServlet("...
- 152
Advice
0
votes
9
replies
121
views
Image not displaying when running Java Servlet project on server (but works when opened directly in browser)
<img src="images/logo.png">
I created a web project using HTML and Servlets (no JSP).
When I open the HTML file directly using “Open in Browser,” the image displays correctly.
But when ...
0
votes
0
answers
63
views
Connecting Java backend(Servlets) to Vercel frontend(fetch API). Cors Error
So basically I have put up my backend on Render web Service (on tomcat) and my frontend(Nextjs) is on Vercel. I have put up a Filter for Cors Policy to intercept all policies and as well as handled ...
- 1
0
votes
1
answer
96
views
How to use slf4j-api > 2 in jersey servlet container
I have a Jersey servlet project, where I organize the depencies with maven. It runs in Tomcat.
Update of slf4j-api
Now I am trying to use <artifactId>slf4j-api</artifactId><version>2....
- 3,313
2
votes
0
answers
84
views
Zombie session after expiring cookies using Java Servlets
I have inherited some JAX-RS code with a logout function that appears to be properly "logging out" the user by redirecting to the login page, invalidating the session, and expiring the ...
- 765
1
vote
1
answer
101
views
How can I capture the full raw HTML content and also set header response value about that content with Servlet Filter
I want to be able to capture HTML content and then set a header about that content using servlet filter.
I Can capture the content but I always get an error that the response has already been ...
- 11.8k
1
vote
1
answer
121
views
How to debug the Tomcat Catalina engine
When I tried doing research on this, everything I found was how to debug an application running under Tomcat. I'm trying to debug Tomcat itself, because something strange is happening that I can't ...
- 15.4k
2
votes
1
answer
291
views
How can I upgrade code that uses Apache Commons FileUpload DiskFileItem for the Jakarta namespace?
I manage a Tomcat/JSP webapp. We are updating our source code to conform to the recent javax -> jakarta namespace change in the Servlet package.
The app uses the Apache Commons FileUpload package, ...
- 583
0
votes
0
answers
64
views
Spring Boot Global Exception Handler Returns 400, but Filter Still Returns 500 When Called by One Particular Caller
1. System Setup
Framework: Spring Boot REST API (servlet-based).
Global Exception Handler:
Uses @RestControllerAdvice to catch MyOperationException.
Returns a ResponseEntity with HTTP 400 and a ...
- 8,395
0
votes
1
answer
174
views
dwr-2024 package throws internal version error
I have an older Java/JSP application that I have to update to Tomcat 10 by May 31, 2025. This change in Tomcat versions covers Java's recent javax -> jakarta API namespace change in the packages ...
- 583