[[oktatas:programozás:java:java_rest_api_kliens|< Java REST API kliens]]

====== Java REST API kliens - HttpClient ======

  * **Szerző:** Sallai András
  * Copyright (c) 2024, Sallai András
  * Szerkesztve: 2024
  * Licenc: [[https://creativecommons.org/licenses/by-sa/4.0/|CC BY-SA 4.0]]
  * Web: https://szit.hu

===== CRUD műveletek aszinkron módban =====

<code java ClientAsync.java>
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpRequest.Builder;
import java.net.http.HttpResponse.BodyHandlers;
import java.util.concurrent.CompletableFuture;

public class ClientAsync {
  
  public static void get() {
    String url = "https://jsonplaceholder.typicode.com/users";
    HttpClient client = HttpClient.newHttpClient();
    Builder request = HttpRequest.newBuilder();
    request.uri(URI.create(url));
    request.GET();

    CompletableFuture<String> res = 
      client.sendAsync(request.build(), 
      BodyHandlers.ofString())
      .thenApply(HttpResponse::body);

    System.out.println(res.join());
  }

  public static void post() {
    String url = "https://jsonplaceholder.typicode.com/users";
    HttpClient client = HttpClient.newHttpClient();
    Builder request = HttpRequest.newBuilder();
    request.uri(URI.create(url));
    request.header("Content-Type", "application/json");
    String body = "{ \"name\": \"John\", \"age\": 30 }";
    request.POST(HttpRequest.BodyPublishers.ofString(body));

    CompletableFuture<String> res = 
      client.sendAsync(request.build(), 
      BodyHandlers.ofString())
      .thenApply(HttpResponse::body);

    System.out.println(res.join());
  }

  public static void put() {
    String url = "https://jsonplaceholder.typicode.com/users/1";
    HttpClient client = HttpClient.newHttpClient();
    Builder request = HttpRequest.newBuilder();
    request.uri(URI.create(url));
    request.header("Content-Type", "application/json");
    String body = "{ \"name\": \"John\", \"age\": 30 }";
    request.PUT(HttpRequest.BodyPublishers.ofString(body));

    CompletableFuture<String> res = 
      client.sendAsync(request.build(), 
      BodyHandlers.ofString())
      .thenApply(HttpResponse::body);

    System.out.println(res.join());
  }

  public static void delete() {
    String url = "https://jsonplaceholder.typicode.com/users/1";
    HttpClient client = HttpClient.newHttpClient();
    Builder request = HttpRequest.newBuilder();
    request.uri(URI.create(url));
    request.DELETE();

    CompletableFuture<String> res = 
      client.sendAsync(request.build(), 
      BodyHandlers.ofString())
      .thenApply(HttpResponse::body);

    System.out.println(res.join());
  }
}

</code>


===== CRUD műveletek szinkron módban =====

<code java Client.java>
import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.net.http.HttpRequest.Builder;
import java.net.http.HttpResponse.BodyHandlers;

public class Client {
  
  public static void get() 
  throws IOException, InterruptedException {
    String url = "https://jsonplaceholder.typicode.com/users";
    HttpClient client = HttpClient.newHttpClient();
    Builder request = HttpRequest.newBuilder();
    request.uri(URI.create(url));
    request.GET();

    HttpResponse<String> res = 
      client.send(request.build(), 
      BodyHandlers.ofString());

    System.out.println(res.body());
  }

  public static void post() 
  throws IOException, InterruptedException {
    String url = "https://jsonplaceholder.typicode.com/users";
    HttpClient client = HttpClient.newHttpClient();
    Builder request = HttpRequest.newBuilder();
    request.uri(URI.create(url));
    request.header("Content-Type", "application/json");
    String body = "{ \"name\": \"John\", \"age\": 30 }";
    request.POST(HttpRequest.BodyPublishers.ofString(body));

    HttpResponse<String> res = 
      client.send(request.build(), 
      BodyHandlers.ofString());

    System.out.println(res.body());
  }

  public static void put() 
  throws IOException, InterruptedException {
    String url = "https://jsonplaceholder.typicode.com/users/1";
    HttpClient client = HttpClient.newHttpClient();
    Builder request = HttpRequest.newBuilder();
    request.uri(URI.create(url));
    request.header("Content-Type", "application/json");
    String body = "{ \"name\": \"John\", \"age\": 30 }";
    request.PUT(HttpRequest.BodyPublishers.ofString(body));

    HttpResponse<String> res = 
      client.send(request.build(), 
      BodyHandlers.ofString());

    System.out.println(res.body());
  }

  public static void delete() 
  throws IOException, InterruptedException {
    String url = "https://jsonplaceholder.typicode.com/users/1";
    HttpClient client = HttpClient.newHttpClient();
    Builder request = HttpRequest.newBuilder();
    request.uri(URI.create(url));
    request.DELETE();

    HttpResponse<String> res = 
      client.send(request.build(), 
      BodyHandlers.ofString());

    System.out.println(res.body());
  }
}

</code>