topic Re: How to extract JSON only if tRest provides data in jsonpath in Talend Studio

How to extract JSON only if tRest provides data in jsonpath

mr_burns — Fri, 15 Nov 2024 22:13:23 GMT

Hi,

I have a tRest and a tExtractJSONFields component like this:

the property "Loop Jsonpath query" of tExtractJSONFields looks like this:

"$.itemgroup[*].item"

but sometimes the arrray 'itemgroup' is not sent back from the server, becuase of e.g. an error, then I get this:

com.jayway.jsonpath.PathNotFoundException: Missing property in path $[itemgroup]

How can I handle this error now? The tExtractJSONFields component has to go on and should not die.

Thanks for any help!

Re: How to extract JSON only if tRest provides data in jsonpath

zjing — Thu, 05 Jan 2023 10:17:22 GMT

hello ,

you need share your your file json

and the configuration de compoment tExtractJsonFileds

according to errer, I think of a worng configuration in compoment tExtractJsonFileds

Re: How to extract JSON only if tRest provides data in jsonpath

mr_burns — Thu, 05 Jan 2023 10:34:53 GMT

in case of success the json looks like this:

{

"itemgroup": [

"item1": {

"name": "item1",

"qty": 5

"item2": {

"name": "item2",

"qty": 17

}

]

}

in case of an error it looks like this:

{

"error": {

"text": [

"Something went wrong"

]

}

The problem is that in case of error the node 'itemgroup' never is returned from the server and this causes the component to die .

I cannot us the tDie component to catch the error because in my job I have a global tLogCatcher with sends an eMail in case of error.

And especially the error of tExtractJsonFields I want to handle in a different way like e.g. put some error message in a database, but only in case of 'itemgroup' is not returned from the server. In any other error cases of tExtractJSONfields the global tLogCatcher should handle this.

Thanks for further help...

Re: How to extract JSON only if tRest provides data in jsonpath

Anonymous — Fri, 06 Jan 2023 08:39:25 GMT

Maybe you can check response string if it contains the 'itemgroup' element, if yes, extract data from response string using tExtractJsonFields, if no, send an email.

eg:

..tRest-main-->tJavaRow--runIf1--tFixedFlowInput--main--tExtractJsonFields

--runIf2--tSendMail

on tJavaRow:

context.response=input_row.Body;

//context.response is a context variable with string type.

if(input_row.Body.contains("itemgroup"){

globalMap.put("continueExtractData",true);

}else{

globalMap.put("continueExtractData",false);

}

set the condition of runIf1 as:

(boolean)globalMap.get("continueExtractData")

set the condition of runIf1 as:

!(boolean)globalMap.get("continueExtractData")

tFixedFlowInput: generate the response string as input row, define one column and set its value as: context.response

Regards

Shong

Re: How to extract JSON only if tRest provides data in jsonpath

mr_burns — Fri, 06 Jan 2023 08:46:45 GMT

thanks shong,

I already could help myself and found an easier way.

Instead using a tRest component I use a tRestClient component now.

tRestClient provides an extra output called 'error' to handle my errors:

The tJavaFlex (you can use a tRavaRow or tJava component as well) is necessary to create the Body for a Post request executed by tRestClient. There is no "Http Body" property like in tRest.

You need to create following output fields for tJavaFlex:

The Java code looks like this:

String payload = "";

payload += "{";

payload += " \"itemgroup\":\"ABC123\", ";

payload += "\"filter\": [\"CurrYear=2023\"]";

payload += "}";

row1.string = payload;

row1.body = payload;

may this helps someone with a similar problem.

Re: How to extract JSON only if tRest provides data in jsonpath

SallyStory — Wed, 22 Feb 2023 05:20:53 GMT

I have also facing the same issue.