[SOLVED] Error while executing background thread HTTP Refresh Service

Setup, Configuration and Use Installation
1

Hi,

all of a sudden, my logs are flooded with the below:
I updated OpenHab to the latest snapshot build, but still this error appears in the logs.
Any help to find the root cause would be appreciated :frowning:
Kurt

[b.core.service.AbstractActiveService] - Error while executing background thread HTTP Refresh Service

java.lang.IllegalArgumentException: json string can not be null or empty

	at com.jayway.jsonpath.internal.Utils.notEmpty(Utils.java:386) [197:com.jayway.jsonpath.json-path:2.1.0]

	at com.jayway.jsonpath.internal.JsonContext.parse(JsonContext.java:81) [197:com.jayway.jsonpath.json-path:2.1.0]

	at com.jayway.jsonpath.JsonPath.read(JsonPath.java:502) [197:com.jayway.jsonpath.json-path:2.1.0]

	at org.eclipse.smarthome.transform.jsonpath.internal.JSonPathTransformationService.transform(JSonPathTransformationService.java:57) [220:org.eclipse.smarthome.transform.jsonpath:0.10.0.201805151356]

	at org.openhab.core.transform.TransformationHelper$TransformationServiceDelegate.transform(TransformationHelper.java:65) [233:org.openhab.core.compat1x:2.3.0.201805141254]

	at org.openhab.binding.http.internal.HttpBinding.execute(HttpBinding.java:194) [228:org.openhab.binding.http:1.12.0.201805060109]

	at org.openhab.core.binding.AbstractActiveBinding$BindingActiveService.execute(AbstractActiveBinding.java:144) [233:org.openhab.core.compat1x:2.3.0.201805141254]

	at org.openhab.core.service.AbstractActiveService$RefreshThread.run(AbstractActiveService.java:166) [233:org.openhab.core.compat1x:2.3.0.201805141254]
2

I assume you are using the HTTP binding? If so I would expect this error if the HTTP request timed out or returned an empty String. Because there is no String to transform, the JSONPATH transform throws an exception.

I don’t think there is a way to solve this except to increase the timeout or make the HTTP service you are polling more reliable.

3

thanks alot for your quick support! It helped to find the bug.
Yes - I’m using the http binding for various usecases.

The one failing was caused by a direct JasonPath transformation to querry data from a text file, which gets downloaded before. Seems like the download failed or corrupted the file.
I re-initiated a download and now the JasonPath transformation works again.

Kurt