JSON Preprocessor

Configurable JSON transformation in Apex.

Specification

This Apex service offers a variety of functionalities to ensure your JSON data is well-organized, matches the requested format and adheres to your preferred formatting standards.

Fields

Field Name	Type	Default	Description
pretty	Boolean	false	Prettify result JSON.
replaceEmptyStringsWithNull	Boolean	false	"" => null
snakeCaseToCamelCase	Boolean	false	some_key => someKey
capitalizeFirstLetter	Boolean	false	someKey => SomeKey
uncapitalizeFirstLetter	Boolean	false	SomeKey => someKey
sortMapFields	Boolean	true	Sort JSON keys.
replaceFieldNamesMap	Map<String,String>		Map JSON keys to a different value. Can be used to change Apex reserved keyword fields before deserialization.
datetimeFieldsToReformat	Set<String>		Collection of JSON keys holding datetime values to reformat.
datetimeFormat	String		Datetime format used for datetimeFieldToReformat JSON fields.
sourceTimeZone	TimeZone	UTC	Original datetime time zone.
targetTimeZone	TimeZone	UTC	Target datetime time zone.

Constructors

Params	Description
	The result JSON won't be prettified
Boolean pretty	The result JSON will be prettified

Methods

Method	Params	Returns	Description
process	String jsonString	String	Process JSON and return a new JSON string.

Example

In the example below, we would like to prepare a JSON for deserialization into an Apex object. We would like to change the original JSON in two ways:

Change the field names from snake case to camel case to follow PMDs field naming conventions.
Change the "number" field name because it's a reserved word in Apex.

JsonPreprocessor processor = new JsonPreprocessor();
processor.snakeCaseToCamelCase = true;
processor.replaceFieldNamesMap.put('number', 'number_x');

String originalJson = '{"some_key":"myValue","number":150}';
String processedJson = processor.process(originalJson);
// {"someKey:"myValue","number_x":150}

Replace Empty Strings with Null

processor.replaceEmptyStringsWithNull = true;
String originalJson = '{"key":""}';
String processedJson = processor.process(originalJson);
// {"key":null}

Snake Case to Camel Case

processor.snakeCaseToCamelCase = true;
String originalJson = '{"some_key":"myValue"}';
String processedJson = processor.process(originalJson);
// {"someKey":"myValue"}

Capitalize and Uncapitalize First Letter

processor.capitalizeFirstLetter = true;
String originalJson = '{"someKey":"myValue"}';
String processedJson = processor.process(originalJson);
// {"SomeKey":"myValue"}

processor.uncapitalizeFirstLetter = true;
String originalJson = '{"SomeKey":"myValue"}';
String processedJson = processor.process(originalJson);
// {"someKey":"myValue"}

Sort Map Fields

processor.sortMapFields = true;
String originalJson = '{"b":"myValue2","a":"myValue"}';
String processedJson = processor.process(originalJson);
// {"a":"myValue","b":"myValue2"}

Replace Fields By Name

processor.replaceFieldNamesMap.put('number', 'ticketNumber');
processor.replaceFieldNamesMap.put('string', 'string_x');
String originalJson = '{"number":150,"string":"myValue"}';
String processedJson = processor.process(originalJson);
// {"ticketNumber":150,"string_x":"myValue"}

Remove Fields By Name

processor.fieldNamesToRemove.add('number');
String originalJson = '{"size":2,"result":[{"number": "ABC0001234","description": "desc1"},{"description": "", "number": "ABC0004567"}]}';
String processedJson = processor.process(originalJson);
// {"size":2,"result":[{"description":"desc1"},{"description":""}]}

Reformat Datetime Values

Let's say in our REST response we have datetime value in Los Angeles time zone, and we are planning to deserialize this JSON into UTC.

Simple example: reformat long datetime.

processor.datetimeFieldsToReformat.add('dt');
String originalJson = '{"dt":1719138444559}';
String result = processor.process(originalJson);
// {"dt":"2024-06-23T10:27:24Z"}

Convert time zones and use custom datetime format example.

processor.datetimeFieldsToReformat.add('dt');
// Default format is yyyy-MM-ddTHH:mm:ssZ
processor.datetimeFormat = 'yyyy-MM-dd\'T\'HH:mm:ss.SSSZ';
// UTC is a default value for both source and target time zone.
processor.sourceTimeZone = TimeZone.getTimeZone('America/Los_Angeles');
processor.targetTimeZone = TimeZone.getTimeZone('UTC');
String originalJson = '{"dt":"2022-12-15 04:15:30"}';
String result = processor.process(originalJson);
// {"dt":"2022-12-15T12:15:30.000+0000"}

Installation

Components

Deploy preprocessor:

sf kratapps remote deploy start \
    --repo-owner kratapps \
    --repo-name component-library \
    -m ApexClass:JsonPreprocessor \
    -m ApexClass:JsonPreprocessorTest \
    -o my-org