rest api java code example

Example 1: rest api

Representational state transfer is a software architectural style that defines
a set of constraints to be used for creating Web services.

Web services that conform to the REST architectural style, called RESTful Web
services, provide interoperability between computer systems on the internet

Example 2: spring @restcontroller

package com.example.restservice;

import java.util.concurrent.atomic.AtomicLong;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class GreetingController {

	private static final String template = "Hello, %s!";
	private final AtomicLong counter = new AtomicLong();

	@GetMapping("/greeting")
	public Greeting greeting(@RequestParam(value = "name", defaultValue = "World") String name) {
		return new Greeting(counter.incrementAndGet(), String.format(template, name));
	}
}Copy

Example 3: rest api

1) REQUEST
2) RESPONSE
When we send request, we need to know the API
methods/endpoints that are available:
		- read documentation about API methods.
		- Swagger tool, that has API methods and descriptions
simple endpoint:
		…school.com/api/students
Types of Requests:
	GET -> Read data
	POST -> Create/insert data
	PUT -> Update data
	DELETE-> Delete data
I send GET, POST, PUT, DELETE type of API requests to
API endpoint/method and get response.
ORDS (oracle data service) API -> HR Database
ORDS API has methods that we can send request to, and it sends
response with Data from HR database.