---

• An HttpClient can be used to send requests and retrieve their responses
• An HttpRequest sets up header and body to API provider
• An HttpResponse is returned as a result of sending an HttpRequest

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://hotels4.p.rapidapi.com/v2/get-meta-data"))
    .header("x-rapidapi-key", "80afb5b6afmsh552d92e769ba3a5p1bfac9jsnfb6c407dd20f")
    .header("x-rapidapi-host", "hotels4.p.rapidapi.com")
    .method("GET", HttpRequest.BodyPublishers.noBody())
    .build();

//RapidAPI request and response
HttpResponse<String> response = HttpClient.newHttpClient().send(request, HttpResponse.BodyHandlers.ofString());

//RapidAPI Body
System.out.println(response.body());

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.Date;
import java.util.HashMap;

import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

@RestController // annotation to create a RESTful web services
@RequestMapping("/api/flights")  //prefix of API
public class flights {
    private JSONObject body; //last run result
    private HttpStatus status; //last run status
    String last_run = null; //last run day of month

    @GetMapping("/monthly")   //added to end of prefix as endpoint
    public ResponseEntity<JSONObject> flights() {

        //calls API once a day, sets body and status properties
        String today = new Date().toString().substring(0,500); 
        if (last_run == null || !today.equals(last_run))
        {
            try { 

                HttpRequest request = HttpRequest.newBuilder()
                 .uri(URI.create("https://hotels4.p.rapidapi.com/v2/get-meta-data"))
                 .header("x-rapidapi-key", "80afb5b6afmsh552d92e769ba3a5p1bfac9jsnfb6c407dd20f")
                 .header("x-rapidapi-host", "hotels4.p.rapidapi.com")
                 .method("GET", HttpRequest.BodyPublishers.noBody())
                 .build();

                //RapidAPI request and response
                HttpResponse<String> response = HttpClient.newHttpClient().send(request, HttpResponse.BodyHandlers.ofString());

                //JSONParser extracts text body and parses to JSONObject
                this.body = (JSONObject) new JSONParser().parse(response.body());
                this.status = HttpStatus.OK;  //200 success
                this.last_run = today;
            }
            catch (Exception e) {  //capture failure info
                HashMap<String, String> status = new HashMap<>();
                status.put("status", "RapidApi failure: " + e);

                //Setup object for error
                this.body = (JSONObject) status;
                this.status = HttpStatus.INTERNAL_SERVER_ERROR; //500 error
                this.last_run = null;
            }
        }

        //return JSONObject in RESTful style
        return new ResponseEntity<>(body, status);
    }
}

|   import org.json.simple.JSONObject;
package org.json.simple does not exist

Benefit of using and API?

• APIs can be found all over the internet. We can just use a few lines of code to get lots of data from the internet, so it is easier, more efficient, and less time consuming.

Benefit(s) of backend implementation?

• Can set limit on how many times an api could run in a day or a month so that it would not exceed the maximun amount; for exmaple, the hotels api (free subscription) only allows the api to be run 500 times per month