======
JSON
======

=> JSON stands for Java Script Object Notation

=> JSON represents data in key-value format

Ex:

	{
		"id" : 101,
		"name" : "Ashok",
		"phno" : 12345,
		"gender" : "Male"
	}

=> JSON is very light weight

=> JSON is platform independent & language independent

=> JSON is used to transfer data over a network	

=> Distributed applications will use JSON data for request & response

=========================================
Working with JSON in Java Applications
==========================================

=> Java Applications can use JSON data

=> To work with JSON in Java app, we have third party libraries

		a) Jackson
		b) Gson

=> By using above libraries we can convert JSON data to Java Object and vice versa


						    jackson/gson
			java obj <----------------------> json data		



=> The process of converting java obj to json is called as Serialization.

=> The process of converting json data to java obj is called as de-serialization.

==============
Jackson API
==============

1) Add below dependency in pom.xml file

		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-databind</artifactId>
			<version>2.17.0</version>
		</dependency>

2) Create binding class to represent data

public class Customer {

	private Integer id;
	private String name;
	private Long phno;

}

3) Develop java class convert java to json and json to java 

		ObjectMapper mapper = new ObjectMapper();

		mapper.writeValue(File f, Object obj);

		mapper.readValue(File f, Class clz);

======================================================================================
public class App {

	public static void main(String[] args) throws Exception {
		App a = new App();
		//a.convertJavaToJson();
		a.convertJsonToJava();
	}
	
	public void convertJsonToJava() throws Exception{
		ObjectMapper mapper = new ObjectMapper();
		Customer c = mapper.readValue(new File("customer.json"), Customer.class);
		System.out.println(c);
	}

	public void convertJavaToJson() throws Exception {
		Customer c = new Customer(101, "John", 9985396677l);
		ObjectMapper mapper = new ObjectMapper();
		mapper.writeValue(new File("customer.json"), c);
		System.out.println("Serialization completed...");
	}
}

=======================================================================================

===========
GSON API
===========

### Git Hub Rep : https://github.com/ashokitschool/GSON-JSON-APP.git

		-----------------------------------------------
		<dependency>
			<groupId>com.google.code.gson</groupId>
			<artifactId>gson</artifactId>
			<version>2.3.1</version>
		</dependency>
		---------------------------------------------

		Gson gson  = new Gson ( );

		gson.toJson(Object obj);

		gson.fromJson(File file);