question Add flow attribute from Json in Support Questions

Add flow attribute from Json

divnid — Thu, 28 Jul 2022 15:05:33 GMT

Hi,

I am trying to add flow attribute from my json file which looks like:

[ {
"name" : "id",
"value" : "29879"
}, {
"name" : "file",
"value" : ""
}, {
"name" : "barcode",
"value" : ""
}, {
"name" : "roll no",
"value" : "3032"
}, {
"name" : "name",
"value" : "Daniel"
}]

Now I want to add roll no. as a flow atrribute using

Can someone please help me with it? Thanks

Re: Add flow attribute from Json

SAMSAL — Thu, 28 Jul 2022 19:10:28 GMT

Hi ,

If you want to extract the value (3032) of the name "roll no" into flowfile attribute called "roll no" you can accomplish this with two processors as follows:

1- EvaluateJsonPath:

roll no = $.[?(@.name=='roll no')].value

Make sure the Return Type is set to Json since the exrepssion above will return json ["3032"].

2- Update Attribute : which will extract the actual value from result json above with the following attribute: roll no = ${'roll no':jsonPath('$[0]')}

Also you can refer to :

https://community.cloudera.com/t5/Support-Questions/Unable-to-return-a-scalar-value-for-the-expression-from-NIFI/td-p/213677

If that helps, please Accept Solution. Thanks

Re: Add flow attribute from Json

divnid — Fri, 29 Jul 2022 12:03:07 GMT

It worked for me. Thanks.