Parse, don't validate (2019)
Please, don&#x27;t write your own JSON parser&#x2F;validator. There&#x27;s JSON Schema <a href="https:&#x2F;&#x2F;json-schema.org" rel="nofollow">https:&#x2F;&#x2F;json-schema.org</a> which has implementations in most languages.
You can valiate your JSON by a given, standardized JSON schema file - and you&#x27;re basically done. 
After the validation, it&#x27;s probably good practise to map the JSON to some DTO and may do some further validation which doesn&#x27;t check the structure of the data but it&#x27;s meaning.