REST api throws 500 on invalid datetime submited

Development
,
1

Hello,

I noticed that when submitting invalid request parameters to the rest api - like invalid datetime (starttime=2025-10-26T07:34:71.502Z) the server throws 500 - Internal Server Error.

I think it would be better to throw 400 - Bad Request in order to help the user resolve the issue faster and easier.

I can make a pull request with

--- a/bundles/org.openhab.core.io.rest.core/src/main/java/org/openhab/core/io/rest/core/internal/JSONResponseExceptionMapper.java
+++ b/bundles/org.openhab.core.io.rest.core/src/main/java/org/openhab/core/io/rest/core/internal/JSONResponseExceptionMapper.java
@@ -13,6 +13,7 @@
 package org.openhab.core.io.rest.core.internal;
 
 import java.io.IOException;
+import java.lang.IllegalArgumentException;
 
 import javax.ws.rs.core.Response;
 import javax.ws.rs.ext.ExceptionMapper;
@@ -50,6 +51,9 @@ public class JSONResponseExceptionMapper implements ExceptionMapper<Exception> {
             logger.debug("Failed writing HTTP response, since other side closed the connection", e);
             // Returning null results in a Response.Status.NO_CONTENT response.
             return null;
+        } else if (e instanceof IllegalArgumentException){
+            logger.debug("Iivalid argument submitted for REST request", e);
+            return JSONResponse.createErrorResponse(Response.Status.BAD_REQUEST, e.getMessage());
         } else {
             logger.error("Unexpected exception occurred while processing REST request.", e);
             return delegate.toResponse(e);

What are your thoughts on this change?

4 Likes
2

A small PR like this wouldn’t take much to create and review. But it might have implications that are not obvious (e.g MainUI, phone apps, BasicUI might depend on that 500 code in some way) so it might grow in scope.

API changes always run the risk of exploding.

I recommend submitting the PR and see what the maintainers think.