Java 11 HttpClient Примеры

В этой статье показано, как использовать новый Java 11 HttpClient API-интерфейсы для отправки HTTP-запросов GET/POST и некоторые часто используемые примеры.

  HttpClient httpClient = HttpClient.newBuilder()
        .version(HttpClient.Version.HTTP_2)
        .followRedirects(HttpClient.Redirect.NORMAL)
        .connectTimeout(Duration.ofSeconds(20))
        .proxy(ProxySelector.of(new InetSocketAddress("proxy.yourcompany.com", 80)))
        .authenticator(Authenticator.getDefault())
        .build();

1. Синхронный Пример

Этот пример отправляет ПОЛУЧИТЬ запрос на https://httpbin.org/get , и распечатайте заголовок ответа, код состояния и текст.

package com.mkyong.java11.jep321;

import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpHeaders;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.time.Duration;

public class HttpClientSynchronous {

    private static final HttpClient httpClient = HttpClient.newBuilder()
            .version(HttpClient.Version.HTTP_1_1)
            .connectTimeout(Duration.ofSeconds(10))
            .build();

    public static void main(String[] args) throws IOException, InterruptedException {

        HttpRequest request = HttpRequest.newBuilder()
                .GET()
                .uri(URI.create("https://httpbin.org/get"))
                .setHeader("User-Agent", "Java 11 HttpClient Bot") // add request header
                .build();

        HttpResponse response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());

        // print response headers
        HttpHeaders headers = response.headers();
        headers.map().forEach((k, v) -> System.out.println(k + ":" + v));

        // print status code
        System.out.println(response.statusCode());

        // print response body
        System.out.println(response.body());

    }

}

Выход

access-control-allow-credentials:[true]
access-control-allow-origin:[*]
connection:[keep-alive]
content-length:[273]
content-type:[application/json]
date:[Sun, 17 May 2020 08:43:18 GMT]
server:[gunicorn/19.9.0]
200
{
  "args": {},
  "headers": {
    "Content-Length": "0",
    "Host": "httpbin.org",
    "User-Agent": "Java 11 HttpClient Bot",
    "X-Amzn-Trace-Id": "Root=1-5ec0f926-5ae58869cfe7162b7c3147fb"
  },
  "origin": "124.82.107.103",
  "url": "https://httpbin.org/get"
}

2. Асинхронный Пример

2.1 HttpClient.SendAsync() чтобы отправить ПОЛУЧИТЬ запрос асинхронно, он вернет Завершаемое будущее

package com.mkyong.java11.jep321;

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
import java.time.Duration;

public class HttpClientAsynchronous {

    private static final HttpClient httpClient = HttpClient.newBuilder()
            .version(HttpClient.Version.HTTP_2)
            .connectTimeout(Duration.ofSeconds(10))
            .build();

    public static void main(String[] args) throws Exception {

        HttpRequest request = HttpRequest.newBuilder()
                .GET()
                .uri(URI.create("https://httpbin.org/get"))
                .setHeader("User-Agent", "Java 11 HttpClient Bot")
                .build();

        CompletableFuture> response =
                httpClient.sendAsync(request, HttpResponse.BodyHandlers.ofString());

        String result = response.thenApply(HttpResponse::body).get(5, TimeUnit.SECONDS);

        System.out.println(result);

    }

}

Выход

{
  "args": {},
  "headers": {
    "Host": "httpbin.org",
    "User-Agent": "Java 11 HttpClient Bot",
    "X-Amzn-Trace-Id": "Root=1-5ec0fb51-2c5dcf98167c6418bd555548"
  },
  "origin": "124.82.107.103",
  "url": "https://httpbin.org/get"
}

3. Пользовательский Исполнитель + Параллельные Запросы

3.1 Добавьте пользовательского исполнителя.

	private final ExecutorService executorService = Executors.newFixedThreadPool(5);

  private final HttpClient httpClient = HttpClient.newBuilder()
          .executor(executorService)
          .build();

3.2 Асинхронно отправлять несколько одновременных запросов.

package com.mkyong.java11.jep321;

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.util.Arrays;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.Collectors;
import java.time.Duration;

public class HttpClientCustomExecutor {

    // custom executor
    private static final ExecutorService executorService = Executors.newFixedThreadPool(5);

    private static final HttpClient httpClient = HttpClient.newBuilder()
            .executor(executorService)
            .version(HttpClient.Version.HTTP_2)
            .connectTimeout(Duration.ofSeconds(10))
            .build();

    public static void main(String[] args) throws Exception {

        List targets = Arrays.asList(
                new URI("https://httpbin.org/get?name=mkyong1"),
                new URI("https://httpbin.org/get?name=mkyong2"),
                new URI("https://httpbin.org/get?name=mkyong3"));

        List> result = targets.stream()
                .map(url -> httpClient.sendAsync(
                        HttpRequest.newBuilder(url)
                                .GET()
                                .setHeader("User-Agent", "Java 11 HttpClient Bot")
                                .build(),
                        HttpResponse.BodyHandlers.ofString())
                        .thenApply(response -> response.body()))
                .collect(Collectors.toList());

        for (CompletableFuture future : result) {
            System.out.println(future.get());
        }

    }

}

Выход

{
"args": {
  "name": "mkyong1"
},
"headers": {
  "Host": "httpbin.org",
  "User-Agent": "Java 11 HttpClient Bot",
  "X-Amzn-Trace-Id": "Root=1-5ec0fd5e-845e2a5889736f9c5bd38a38"
},
"origin": "124.82.107.103",
"url": "https://httpbin.org/get?name=mkyong1"
}

{
"args": {
  "name": "mkyong2"
},
"headers": {
  "Host": "httpbin.org",
  "User-Agent": "Java 11 HttpClient Bot",
  "X-Amzn-Trace-Id": "Root=1-5ec0fd5e-d365205a75254575c9705ca0"
},
"origin": "124.82.107.103",
"url": "https://httpbin.org/get?name=mkyong2"
}

{
"args": {
  "name": "mkyong3"
},
"headers": {
  "Host": "httpbin.org",
  "User-Agent": "Java 11 HttpClient Bot",
  "X-Amzn-Trace-Id": "Root=1-5ec0fd5e-cd61de10889128921dad6008"
},
"origin": "124.82.107.103",
"url": "https://httpbin.org/get?name=mkyong3"
}

4. Параметры формы публикации

4.1 Java 11 HttpКлиент не предоставил API для данных формы, мы должны создать его вручную.

package com.mkyong.java11.jep321;

import java.io.IOException;
import java.net.URI;
import java.net.URLEncoder;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.nio.charset.StandardCharsets;
import java.time.Duration;
import java.util.HashMap;
import java.util.Map;

public class HttpClientPostForm {

    private static final HttpClient httpClient = HttpClient.newBuilder()
            .version(HttpClient.Version.HTTP_2)
            .connectTimeout(Duration.ofSeconds(10))
            .build();

    public static void main(String[] args) throws IOException, InterruptedException {

        // form parameters
        Map data = new HashMap<>();
        data.put("username", "abc");
        data.put("password", "123");
        data.put("custom", "secret");
        data.put("ts", System.currentTimeMillis());

        HttpRequest request = HttpRequest.newBuilder()
                .POST(ofFormData(data))
                .uri(URI.create("https://httpbin.org/post"))
                .setHeader("User-Agent", "Java 11 HttpClient Bot") // add request header
                .header("Content-Type", "application/x-www-form-urlencoded")
                .build();

        HttpResponse response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());

        // print status code
        System.out.println(response.statusCode());

        // print response body
        System.out.println(response.body());

    }

    // Sample: 'password=123&custom=secret&username=abc&ts=1570704369823'
    public static HttpRequest.BodyPublisher ofFormData(Map data) {
        var builder = new StringBuilder();
        for (Map.Entry entry : data.entrySet()) {
            if (builder.length() > 0) {
                builder.append("&");
            }
            builder.append(URLEncoder.encode(entry.getKey().toString(), StandardCharsets.UTF_8));
            builder.append("=");
            builder.append(URLEncoder.encode(entry.getValue().toString(), StandardCharsets.UTF_8));
        }
        return HttpRequest.BodyPublishers.ofString(builder.toString());
    }

}

Выход

200
{
"args": {},
"data": "",
"files": {},
"form": {
  "custom": "secret",
  "password": "123",
  "ts": "1589706608386",
  "username": "abc"
},
"headers": {
  "Content-Length": "56",
  "Content-Type": "application/x-www-form-urlencoded",
  "Host": "httpbin.org",
  "User-Agent": "Java 11 HttpClient Bot",
  "X-Amzn-Trace-Id": "Root=1-5ec0ff71-9f0cc3e2bc88b1c0c9c66a43"
},
"json": null,
"origin": "124.82.107.103",
"url": "https://httpbin.org/post"
}

5. ОПУБЛИКОВАТЬ JSON

package com.mkyong.java11.jep321;

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.time.Duration;

public class HttpClientPostJSON {

    private static final HttpClient httpClient = HttpClient.newBuilder()
            .version(HttpClient.Version.HTTP_2)
            .connectTimeout(Duration.ofSeconds(10))
            .build();

    public static void main(String[] args) throws IOException, InterruptedException {

        // json formatted data
        String json = new StringBuilder()
                .append("{")
                .append("\"name\":\"mkyong\",")
                .append("\"notes\":\"hello\"")
                .append("}").toString();

        // add json header
        HttpRequest request = HttpRequest.newBuilder()
                .POST(HttpRequest.BodyPublishers.ofString(json))
                .uri(URI.create("https://httpbin.org/post"))
                .setHeader("User-Agent", "Java 11 HttpClient Bot") // add request header
                .header("Content-Type", "application/json")
                .build();

        HttpResponse response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());

        // print status code
        System.out.println(response.statusCode());

        // print response body
        System.out.println(response.body());

    }

}

Выход

200
{
"args": {},
"data": "{\"name\":\"mkyong\",\"notes\":\"hello\"}",
"files": {},
"form": {},
"headers": {
  "Content-Length": "33",
  "Content-Type": "application/json",
  "Host": "httpbin.org",
  "User-Agent": "Java 11 HttpClient Bot",
  "X-Amzn-Trace-Id": "Root=1-5ec0fff9-3f6613c39c502fa5e1b79afa"
},
"json": {
  "name": "mkyong",
  "notes": "hello"
},
"origin": "124.82.107.103",
"url": "https://httpbin.org/post"
}

6. Идентификация

6.1 Запустите простое Веб-приложение Spring Security, обеспечивающее базовую аутентификацию HTTP , и протестируйте его с помощью новых API Java 11 HttpClient

package com.mkyong.java11.jep321;

import java.io.IOException;
import java.net.Authenticator;
import java.net.PasswordAuthentication;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.time.Duration;

// start this https://mkyong.com/spring-boot/spring-rest-spring-security-example/
public class HttpClientAuthentication {

    private static final HttpClient httpClient = HttpClient.newBuilder()
            .authenticator(new Authenticator() {
                @Override
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication(
                            "user",
                            "password".toCharArray());
                }

            })
            .connectTimeout(Duration.ofSeconds(10))
            .build();

    public static void main(String[] args) throws IOException, InterruptedException {

        HttpRequest request = HttpRequest.newBuilder()
                .GET()
                .uri(URI.create("http://localhost:8080/books"))
                .setHeader("User-Agent", "Java 11 HttpClient Bot") // add request header
                .build();

        HttpResponse response = httpClient.send(request, HttpResponse.BodyHandlers.ofString());

        // print status code
        System.out.println(response.statusCode());

        // print response body
        System.out.println(response.body());

    }

}

7. Часто задаваемые вопросы

7.1 Отключено перенаправление.

	private final HttpClient httpClient = HttpClient.newBuilder()
            .followRedirects(HttpClient.Redirect.NEVER)
            .build();

Прочтите это HttpClient. Перенаправление JavaDoc

7.2 Тайм-аут, 5 секунд.

	private final HttpClient httpClient = HttpClient.newBuilder()
            .connectTimeout(Duration.ofSeconds(5))
            .build();

7.3 Установите прокси-сервер.

	private final HttpClient httpClient = HttpClient.newBuilder()
            .proxy(ProxySelector.of(new InetSocketAddress("your-company-proxy.com", 8080)))
            .build();

Скачать Исходный Код

$клон git $клон git

$компакт-диск java-11

найти jep-321

1. Синхронный Пример

2. Асинхронный Пример

3. Пользовательский Исполнитель + Параллельные Запросы

4. Параметры формы публикации

5. ОПУБЛИКОВАТЬ JSON

6. Идентификация

7. Часто задаваемые вопросы

Скачать Исходный Код

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