Java REST API kliens - HttpClient

Szerző: Sallai András
Copyright © 2024, Sallai András
Szerkesztve: 2024
Licenc: CC BY-SA 4.0
Web: https://szit.hu

CRUD műveletek aszinkron módban

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());
  }
}

CRUD műveletek szinkron módban

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());
  }
}