Logstash Ruby How to get fields of json array

Elastic Stack Logstash
1

Hi I have an array

"testItem":["test1":"N", "test2":"", "test3":"xyz", "items":{"itemId":"123"},"test4","null"]

In here I want to extract the itemId from Json input through logstash how can i do it. I am new to logstash.

if [testItems][items][itemId] contains
then copy => {"itemId"=>%[testItems][items][itemId]}

thanks for help

2

This is not valid JSON, and it is unclear to me what structure you are trying to express. Can you provide more detail about what you are attempting to accomplish?