This document discusses Salesforce's new support for JSON in Winter 12. It provides an overview of what JSON is and its advantages over XML. It then covers how to deserialize and serialize JSON to and from Apex classes in Salesforce with a single line of code. It also demonstrates how to output Visualforce pages in JSON format and includes an example of calling the Google Maps Distance Matrix API to get distance information in JSON format and deserializing the response.

1. Salesforce JSON support
Winter 12
By – Jitendra Zaa
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2. Agenda
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•
•
•
•
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What is JSON
Advantage of JSON over XML
Other reasons to use JSON
JSON Syntax / Guidelines
Deserialize and Serialize in Single line - Winter 12
Visualforce Page Output as JSON
Google Map API - Demo
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3. What is JSON
•
•
•
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JSON Stands for “JavaScript Object Notation”.
Language Independent representation of objects.
Parsers widely available in many languages.
Alternative to XML.
JSON can be transmitted over http / https.
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4. XML Example
<Person>
<FirstName>Foo</FirstName>
<LastName>Bar</LastName>
</person>
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5. JSON Example
{
“FirstName” : “Foo”,
“LastName” : “Bar”
}
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6. JSON Advantage over XML
• XML is Verbose.
• More size than of equivalent JSON representation
because of repeated Tags.
• JSON Simple to represent
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7. Why JSON
• REST is very common and supports JSON widely.
• REST and JSON are the music of the internet.
• Google , Yahoo, D&B web services exposed as REST
with response type JSON.
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8. JSON Guidelines
Key – Value enclosed in double quotes (String).
Value - can again anything of datatype.
{} – represents Object
[] – represents Array
, - Separates data element within Object
Supports basically four data type:
1. Boolean
2. Number
3. String
4. Object
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9. Nested Object JSON
{
“FirstName” : “Foo”,
“LastName” : “Bar”,
“Address” :
{
“city” : “Pune”,
“state” : “Maharashtra”,
“country” : “India”
}
}
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10. How to Work with JSON – Before
Winter 12
• AppExchange and other codes were available for
Parsing JSON.
• Performance Overhead.
• Learning curve more.
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11. Deserialize JSON – Winter 12 API
JSON String :
{
“FirstName” : “Foo”,
“LastName” : “Bar”
}
Equivalent Apex Class:
Class Person
{
public String FirstName;
public String LastName;
}
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12. Deserialize JSON – Single Line
Person d = (Person )System.JSON.deserialize(jsonString, Person.class);
JSON Format String
Determine the output
object type of the JSON
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13. Serialize Apex Class to JSON
JSON.serialize(object);
Object to convert to
JSON
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14. JSON MIME Type
• application/json
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15. Visualforce Page Output as JSON
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contentType="application/x-JavaScript; charset=utf-8"
showHeader="false"
standardStylesheets="false"
sidebar="false"
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16. Demo
Get distance between two points using Google API
http://maps.googleapis.com/maps/api/distancematrix/json?origi
ns=Nagpur+Maharashtra+india&destinations=Pune+Maharasht
ra+india&sensor=false
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17. Response from Google
{
}
destination_addresses:[
"Pune, Maharashtra, India"
],
origin_addresses:[
"Nagpur, Maharashtra, India"
],
rows:[
{
elements:[
{
distance:{
text:"730 km",
value:730315
},
duration:{
text:"11 hours 25 mins",
value:41126
},
status:"OK"
}
]
}
],
status:"OK"
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18. Apex Class Equivalent to JSON
response
Class GoogleResponse
{
public String[] destination_addresses;
public String[] origin_addresses;
public Row[] rows;
public String status;
}
Class Row
{
public Elements[] elements;
}
Class Elements
{
public
public
public
}
Class Values
{
public
public
}
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Values distance;
Values duration;
String status;
String text;
String value;

19. Deserialize JSON
String json = '{ "destination_addresses":[ "Pune, Maharashtra, India" ],
"origin_addresses":[ "Nagpur, Maharashtra, India" ],"rows":[
{
"elements":[
{
"distance":{
"text":"730 km",
"value":730315
},
"duration":{
"text":"11 hours
25 mins",
"value":41126
},
"status":"OK"
}
]
} ], "status":"OK"}';
GoogleResponse d = (GoogleResponse)System.JSON.deserialize(json,
GoogleResponse.class);
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