This document discusses parsing JSON payloads in Mulesoft. It provides an example of a simple JSON payload containing book data with category, author, title, and price fields. It then shows a Mule flow that uses the JSON-to-object-transformer and collection splitter to parse this payload and log the values of each field.

1. JSON Parser

2. JSON (JavaScript Object Notation) is a lightweight data-
interchange format. It is easy for humans to read and
write. It is easy for machines to parse and generate. It is
based on a subset of the JavaScript Programming
Language, Standard ECMA-262 3rd Edition - December
1999.

3. So, there can be different JSON payload ..
One of the simple JSON payload is as follows :-
[
{
"category": "reference",
"author": "Nigel Rees",
"title": "Sayings of the Century",
"price": 8.95
},
{
"category": "fiction",
"author": "Evelyn Waugh",
"title": "Sword of Honour",
"price": 12.99
}
]

4. You can see the JSON request is formed as a list where the
attributes like "category,"author”,"title“ and "price":
8.95 is repeating in a list….
So how can we parse it and
extract the value of each
components ?????

5. Now there are various ways to use this new component….
I will show you small examples here

6. Let us consider following small example:-
Here in this flow we are setting the JSON in set payload component
and extracting the values of each JSON attributes in logger

7. Corresponding Mule flow will be :-
<flow name="testxmlFlow1" doc:name="testxmlFlow1">
<http:inbound-endpoint address="http://localhost:1081/order" exchange-pattern="request-response"
doc:name="HTTP" doc:description="Process HTTP reqests or responses."/>
<set-payload value="[{ &quot;category&quot;: &quot;reference&quot;,&quot;author&quot;: &quot;Nigel
Rees&quot;,&quot;title&quot;: &quot;Sayings of the Century&quot;,&quot;price&quot;: 8.95},{
&quot;category&quot;: &quot;fiction&quot;,&quot;author&quot;: &quot;Evelyn
Waugh&quot;,&quot;title&quot;: &quot;Sword of Honour&quot;,&quot;price&quot;: 12.99}]"
doc:name="Set Payload"/>
<json:json-to-object-transformer returnClass="java.util.List" doc:name="JSON to List" />
<collection-splitter doc:name="Collection Splitter"/>
<logger message="#[message.payload.category] and #[message.payload.author] and
#[message.payload.title] and #[message.payload.price]" level="INFO" doc:name="Logger"/>
</flow>

8. Here you can see I have used JSON to List transformer in
the flow :- <json:json-to-object-transformer
returnClass="java.util.List" doc:name="JSON to List" />
We have also used collection splitter to split the values
of the list :-

9. So, now let run the application and hit the url :-
http://localhost:1081/order to start the application

10. In the following you can see that the attributes value are
extracted and displayed in logger in Mule console in following
way :-

11. In next slides I will bring you some more basic concepts of
parsing some more complex JSON payloads