1. Java11時代のHTTPアクセス再入門
JJUG CCC 2019 Spring
@tamtam180
2019/05/18

2. アジェンダ
• 自己紹介
• おさらい
– HttpUrlConnectionの話
– Apache HttpClientの話
• java.net.http.HttpClientの話

3. アジェンダ
• 話さないこと
– HTTP/2の基本的な話

4. 自己紹介
• Name: Kiyotaka Suzuki
• Twitter: @tamtam180
• Main works
– Square Enix (5.5 Year)
• PlayOnline, FF-XIV, etc,
– SmartNews (5 Year)
• Cross functional Expert Team
• Senior Software Engineer
• Advertising System, PoC, SRE, etc,..
• I Love OSS about Datastore
• Mad performance tuner

5. その前に
• 検証に便利なWebサイト
– https://http2.pro/api/v1
• HTTP/2のテスト
– https://httpbin.org/
• HTTPメソッド、ステータス、Cookie、Cache、etc
• このサイトでほぼ事足りる
– https://httpstat.us/
• HTTPステータス
– https://badssl.com/
• HTTPSのエラーテスト
– https://www.websocket.org/echo.html
• WebSocketのテスト

6. おさらい
• 今までの主なHTTPアクセス
– HttpUrlConnection
– Apache HttpClient
– OkHttp

7. おさらい
• HttpUrlConnection
– 同期処理だけ
– HTTP1.1まで
– Cookieは一応扱える
• OnMemory
– Basic認証も出来る
• QueryStringを作るのが大変（個人的感想）
• Responseのgzip処理とか大変

8. おさらい
• Apache HTTPClient
– 5系からHTTP/2が使える（5系はβバージョン）
– 3系から4系でプログラムの構造が大きく変更
• Commons HttpClientは3系, もう古い
– IO Model
• Blocking I/O
– Classic Java IO
– Non blocking
• Event Driven I/O with JavaNIO

9. おさらい
• Apache HTTPClient
– Core
• v4.4
• v5.0 beta
– Client
• v4.5
• v5.0 beta
– HttpAsyncClient
• v4.1

10. おさらい
• OkHttp (v3.14.1)
– HTTP/2対応
– Androidも対応
• Android5.0+ (API Level 21+)
– Java8+
– TLS1.3対応

11. おさらい
• java.net.http / HttpClient
– HTTP/2対応
– WebSocket対応
– 同期/非同期 処理対応
– Reactive Streamとして
Request/Responseを処理
– Builderパターン

12. おさらい HttpUrlConnection

13. おさらい: HttpUrlConnection
• GET
var url = new URL("https://httpbin.org/get");
var conn = (HttpURLConnection) url.openConnection();
try (InputStream in = conn.getInputStream()) {
System.out.println(conn.getResponseCode());
System.out.println(IOUtils.toString(in, StandardCharsets.UTF_8));
}
conn.disconnect();
"headers": {
"Accept": "text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2",
"Host": "httpbin.org",
"User-Agent": "Java/11.0.2"
}

14. おさらい: HttpUrlConnection
• メソッドを変更する(例えばHEAD)
conn.setRequestMethod("HEAD");

15. おさらい: HttpUrlConnection
• Request Headerを弄る
conn.setRequestProperty("User-Agent", "MyJava/11.0.0");
conn.setRequestProperty("Content-Type", "application/json");

16. おさらい: HttpUrlConnection
• BODYを送信する
conn.setDoOutput(true);
try (var writer = new OutputStreamWriter(conn.getOutputStream())) {
writer.write(new Gson().toJson(Map.of("hello", "world")));
writer.flush();
}

17. おさらい: HttpUrlConnection
• POST（組み合わせ）
var url = new URL("http://httpbin.org/post");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setDoOutput(true);
conn.setRequestMethod("POST");
conn.setRequestProperty("User-Agent", "MyJava/11.0.0");
conn.setRequestProperty("Content-Type", "application/json");
try (OutputStreamWriter writer = new OutputStreamWriter(conn.getOutputStream())) {
writer.write(new Gson().toJson(Map.of("hello", "world")));
writer.flush();
}
try (InputStream in = conn.getInputStream()) {
System.out.println(conn.getResponseCode());
System.out.println(IOUtils.toString(in, StandardCharsets.UTF_8));
}
conn.disconnect();

18. おさらい: HttpUrlConnection
• Cookie
– CookieManager, CookieHandlerを使う
– 世の中にあるサンプル、本当に動く？？
– CookieManagerはThreadSafeじゃない
CookieManager cookieManager = new CookieManager(null, CookiePolicy.ACCEPT_ALL);
CookieHandler.setDefault(cookieManager);
System.out.println(conn.getResponseCode());
CookieHandler.getDefault().put(conn.getURL().toURI(), conn.getHeaderFields());
for (HttpCookie cookie : cookieManager.getCookieStore().get(conn.getURL().toURI())) {
System.out.println(cookie);
}
これが無いと動かないのだけど..

19. おさらい: HttpUrlConnection
• Proxy
var proxy = new Proxy(
Proxy.Type.SOCKS,
InetSocketAddress.createUnresolved("127.0.0.1", 7777));
HttpURLConnection conn = (HttpURLConnection)
url.openConnection(proxy);
ssh any-server –D7777
HTTP Proxyの場合は、 Proxy.Type.HTTP

20. おさらい: HttpUrlConnection
• Redirect
– デフォルトはredirectを追従
var url = new URL("https://httpbin.org/redirect/2");
var conn = (HttpURLConnection) url.openConnection();
conn.setInstanceFollowRedirects(true);

21. おさらい: HttpUrlConnection
• Basic認証
– Header直接指定
– java.net.Authenticator
• requestPasswordAuthenticationInstanceを
上書き
• getPasswordAuthenticationを上書き

22. おさらい: HttpUrlConnection
• Basic認証
– Header直接指定
var url = new URL("https://httpbin.org/basic-auth/test-user/test-pass");
var conn = (HttpURLConnection) url.openConnection();
conn.setRequestProperty(
"Authorization",
"Basic " + Base64.getEncoder().encodeToString("test-user:test-
pass".getBytes()));

23. おさらい: HttpUrlConnection
• Basic認証
– java.net.Authenticator その1
Authenticator.setDefault(new Authenticator() {
@Override
protected PasswordAuthentication getPasswordAuthentication() {
if (getRequestorType() != RequestorType.SERVER) return null;
if (!"basic".equals(getRequestingScheme())) return null;
if ("httpbin.org".equalsIgnoreCase(getRequestingHost())) {
return new PasswordAuthentication("test-user", "test-pass".toCharArray());
}
return null;
}
});

24. おさらい: HttpUrlConnection
• Basic認証
– java.net.Authenticator その2
Authenticator.setDefault(new Authenticator() {
@Override
public PasswordAuthentication requestPasswordAuthenticationInstance(String
host, InetAddress addr, int port, String protocol, String prompt, String scheme,
URL url, RequestorType reqType) {
if (reqType != RequestorType.SERVER) return null;
if (!"basic".equals(scheme)) return null;
if ("httpbin.org".equalsIgnoreCase(host)) {
return new PasswordAuthentication("test-user", "test-pass".toCharArray());
}
return null;
}
});

25. おさらい: HttpUrlConnection
• SSL Errorを無視する通信
SSLContext sslcontext = SSLContext.getInstance("SSL");
sslcontext.init(null, new TrustManager[]{new X509TrustManager() {
public void checkClientTrusted(X509Certificate[] x509Certificates, String s) {}
public void checkServerTrusted(X509Certificate[] x509Certificates, String s) {}
public X509Certificate[] getAcceptedIssuers() { return null; }
}}, null);
HttpsURLConnection.setDefaultHostnameVerifier((s, sslSession) -> true);
var url = new URL("https://expired.badssl.com/");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
if (conn instanceof HttpsURLConnection) {
((HttpsURLConnection) conn).setSSLSocketFactory(sslcontext.getSocketFactory());
}
SSLContext
Verifier
SocketFactory

26. おさらい: HttpUrlConnection
• デバッグの方法
– Logger指定
– java.net.debug

27. おさらい: HttpUrlConnection
• Logger指定
[logging.properties]
handlers = java.util.logging.ConsoleHandler
java.util.logging.ConsoleHandler.level = ALL
sun.net.www.protocol.http.HttpURLConnection.level = ALL
System.setProperty("java.util.logging.config.file", "logging.properties");

28. おさらい: HttpUrlConnection
• javax.net.debug
– Helpを指定するとhelpが表示される
System.setProperty("javax.net.debug", ”help");
URL url = new URL("https://www.google.com");
var conn = (HttpURLConnection) url.openConnection();
conn.getInputStream();
https://docs.oracle.com/javase/jp/8/docs/technotes/guides/security/jsse/JSSERefGuide.html
https://www.ibm.com/support/knowledgecenter/en/SSYKE2_7.0.0/com.ibm.java.security.component.70.doc/security-
all
ssl:record,handshake,keygen,session,defaultctx,sslctx,sessioncache,keymanager,trustmanager,plugga
bility
handshake:data,verbose
plaintext,packet
指定可能な値
例: ssl:handshake,session
例: all
カンマ区切りかコロン区切り

29. Apache HttpClient

30. ApacheHC/GET
• GET
var clientBuilder = HttpClientBuilder.create();
try (CloseableHttpClient client = clientBuilder.build()) {
var getMethod = new HttpGet(URI.create("http://httpbin.org/get"));
try (CloseableHttpResponse resp = client.execute(getMethod)) {
String body = EntityUtils.toString(resp.getEntity(), StandardCharsets.UTF_8);
System.out.println(resp.getStatusLine());
System.out.println(body);
}
}

31. ApacheHC/Accept Header
• 注意点
– デフォルトのヘッダはAccept Header無し
Host: httpbin.org
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.5.4 (Java/11.0.1)
Accept-Encoding: gzip,deflate

32. ApacheHC/Accept Header
• Accept Header
• (指定が無い場合は何でも受け付ける事を意
味する)
• と、書いてあるのに..
RFC7231: Section 5.3.2
A request without any Accept header field implies that the user
agent will accept any media type in response.
https://tools.ietf.org/html/rfc7231#section-5.3.2

33. ApacheHC/Accept Header
• サイトによっては正しく返却されない
– 例: http://httpstat.us/200
curl -H "Accept: */*" http://httpstat.us/200
# Content-Length: 6
200 OK
curl -H "Accept:" http://httpstat.us/200
# Content-Length: 0

34. ApacheHC/Accept Header
• 各ブラウザのAccept Header
– デフォルト値の一覧は以下のサイトを参照
https://developer.mozilla.org/en-
US/docs/Web/HTTP/Content_negotiation/List_of_default_Accept_values

35. ApacheHC/Gzip
• Gzipはデフォルトで処理される
– gzipもdeflateも
curl -s http://httpbin.org/gzip | gzip -d
var clientBuilder = HttpClientBuilder.create();
try (CloseableHttpClient client = clientBuilder.build()) {
var getMethod = new HttpGet("http://httpbin.org/gzip");
try (var resp = client.execute(getMethod)) {
String body = EntityUtils.toString(resp.getEntity(), StandardCharsets.UTF_8);
System.out.println(body);
}
}
本当はAccept Encodingを付ける必要がある。
httpbin.org/gzip や httpbin.org/deflate は
それを無視して送ってくるのでコードでは省略している。

36. ApacheHC
• Queryを作る時は URI Builder
var uri = new URIBuilder("http://httpbin.org/get")
.setCharset(StandardCharsets.UTF_8)
.addParameter("hello", "world")
.addParameter("sushi", "寿司")
.setScheme("https") // HTTPSに変更
.setFragment("hello")
.build();
https://httpbin.org/get?hello=world&sushi=%E5%AF%BF%E5%8F%B8#hello

37. ApacheHC
• Connection Pool
var connManager = new PoolingHttpClientConnectionManager();
connManager.setMaxTotal(100);
connManager.setDefaultMaxPerRoute(100);
var clientBuilder = HttpClientBuilder.create();
clientBuilder.setConnectionManager(connManager);

38. ApacheHC
• Request Headerをいじる
var clientBuilder = HttpClientBuilder.create();
var defaultHeaders = Arrays.asList(
new BasicHeader("Accept", "*/*")
);
clientBuilder.setDefaultHeaders(defaultHeaders);
var getMethod = new HttpGet(URI.create("http://httpbin.org/get"));
getMethod.setHeader("Accept", "*/*");
定数クラスがあるのでそれを使うと良い
HttpHeaders, ContentType

39. ApacheHC/POST
var clientBuilder = HttpClientBuilder.create();
try (CloseableHttpClient client = clientBuilder.build()) {
String jsonText = new Gson().toJson(Map.of("hello", "world"));
HttpEntity entity = EntityBuilder.create()
.setContentType(ContentType.APPLICATION_JSON)
.setText(jsonText).build();
HttpPost postMethod = new HttpPost(URI.create("http://httpbin.org/post"));
postMethod.setEntity(entity);
try (CloseableHttpResponse resp = client.execute(postMethod)) {
String body = EntityUtils.toString(resp.getEntity(), StandardCharsets.UTF_8);
System.out.println(resp.getStatusLine());
System.out.println(body);
}
}

40. ApacheHC
• やり方色々
– Client
• HttpClientBuilder.create().build();
• HttpClients.custom().build();
• HttpClients.createDefault();
– Entity
• EntityBuilder
• 直接生成
BasicHttpEntity
BufferedHttpEntity
ByteArrayEntity
FileEntity
InputStreamEntity
SerializableEntity
StringEntity

41. ApacheHC
• やり方色々
– execute
• 単純に実行
• HttpContext
• ResponseHandler

42. ApacheHC
• Responseの処理はEntityUtilsが便利
– toString()
– toByteArray()
– writeTo()
– consume()
– ...

43. ApacheHC/Redirect
• デフォルトで追従
• OFFにする場合は、RequestConfig
var requestConfig = RequestConfig.custom()
.setRedirectsEnabled(false) //追従しない
.build();
var clientBuilder = HttpClientBuilder.create();
clientBuilder.setDefaultRequestConfig(requestConfig);
var getMethod = new
HttpGet(URI.create("http://httpbin.org/redirect/3"));
getMethod.setConfig(requestConfig);

44. ApacheHC/Retry
• DefaultHttpRequestRetryHandler
– ConnectTimeoutExceptionはRetryしない
– InterruptedIOExceptionのSubClassだけど
https://hc.apache.org/httpcomponents-client-
ga/httpclient/apidocs/org/apache/http/impl/client/DefaultHttpRequestRetryHandler.html

45. ApacheHC/Cookie
var cookieStore = new BasicCookieStore();
var clientBuilder = HttpClientBuilder.create();
clientBuilder.setDefaultCookieStore(cookieStore);
// return Set-Cookie
try (CloseableHttpClient client = clientBuilder.build()) {
var get = new HttpGet("https://httpbin.org/cookies/set/hello/world");
try (CloseableHttpResponse resp = client.execute(get)) {}
}
// send Cookie: hello and sushi
var cookie = new BasicClientCookie("sushi", " 🍣");
cookie.setDomain("httpbin.org");
cookieStore.addCookie(cookie);
try (CloseableHttpClient client = clientBuilder.build()) {
var get = new HttpGet("https://httpbin.org/cookies");
try (CloseableHttpResponse resp = client.execute(get)) {}
}
GET /cookies HTTP/1.1
Host: httpbin.org
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.5.4 (Java/11.0.1
Cookie: hello=world; sushi= 🍣
Accept-Encoding: gzip,deflate

46. • Proxy
• 認証有りProxy
ApacheHC/Proxy
var clientBuilder = HttpClientBuilder.create();
var proxy = new HttpHost(proxyHost, proxyPort, "http");
clientBuilder.setProxy(proxy);
clientBuilder.setProxyAuthenticationStrategy(new ProxyAuthenticationStrategy());
var credsProvider = new BasicCredentialsProvider();
credsProvider.setCredentials(
AuthScope.ANY,
new UsernamePasswordCredentials(proxyUser, proxyPassword));
clientBuilder.setDefaultCredentialsProvider(credsProvider);

47. ApacheHC
• Basic認証
var u = URI.create("https://httpbin.org/basic-auth/kuma/pass");
var credProvider = new BasicCredentialsProvider();
credProvider.setCredentials(
new AuthScope(u.getHost(), u.getPort(), AuthScope.ANY_REALM,
AuthScope.ANY_SCHEME),
new UsernamePasswordCredentials("kuma", "pass"));
var clientBuilder = HttpClientBuilder.create();
clientBuilder.setDefaultCredentialsProvider(credProvider);
try (CloseableHttpClient client = clientBuilder.build()) {
var getMethod = new HttpGet(u);
try (CloseableHttpResponse resp = client.execute(getMethod)) {
System.out.println(resp.getStatusLine());
}
}

48. ApacheHC
• Basic認証 (ANYを使う:非推奨)
– 最低限、Host, Portは指定した方が良い
– Realmも本当は指定した方が良いけど
credProvider.setCredentials(
AuthScope.ANY,
new UsernamePasswordCredentials("kuma", "pass"));

49. ApacheHC/BadSSL
• BadSSLスルー
var sslContext = SSLContext.getInstance("SSL");
sslContext.init(null, new TrustManager[] { new X509TrustManager() {
public X509Certificate[] getAcceptedIssuers() { return null; }
public void checkClientTrusted(X509Certificate[] certs, String authType) { }
public void checkServerTrusted(X509Certificate[] certs, String authType) { }
} }, new SecureRandom());
var clientBuilder = HttpClientBuilder.create();
clientBuilder.setSSLSocketFactory(new SSLConnectionSocketFactory(sslContext));
try (CloseableHttpClient client = clientBuilder.build()) {
var getMethod = new HttpGet("https://expired.badssl.com/");
try (var resp = client.execute(getMethod)) {
String body = EntityUtils.toString(resp.getEntity(), StandardCharsets.UTF_8);
System.out.println(body);
}
}

50. ApacheHC/Async
• HttpAsyncClient
– Basicな方法
CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
client.start();
var request1 = new HttpGet("https://httpbin.org/get");
Future<HttpResponse> future = client.execute(request1, null);
// any processing
var resp = future.get();
System.out.println(resp.getStatusLine());
client.close();

51. ApacheHC/Async
• HttpAsyncClient
– Consumer / Producer
CloseableHttpAsyncClient client = HttpAsyncClients.createDefault();
client.start();
var producer = HttpAsyncMethods.create(new HttpGet("https://httpbin.org/get"));
var consumer = new AsyncCharConsumer<HttpResponse>() {
HttpResponse response;
protected void onCharReceived(CharBuffer charBuffer, IOControl ioControl) { }
protected void onResponseReceived(HttpResponse httpResponse) {
this.response = httpResponse;
}
protected HttpResponse buildResult(HttpContext httpContext) { return this.response; }
};

52. ApacheHC/Async
• HttpAsyncClient
– Consumer / Producer
var latch = new CountDownLatch(1);
client.execute(producer, consumer, new FutureCallback<>() {
public void completed(HttpResponse httpResponse) { latch.countDown(); }
public void failed(Exception e) { latch.countDown(); }
public void cancelled() { latch.countDown(); }
});
latch.await();
System.out.println(consumer.response.getStatusLine());
client.close();

53. ApacheHC/Debug
• DEBUG
– Loggerを設定する
– Lobackの例
<logger name="org.apache.http" additivity="true">
<level value="DEBUG"/>
</logger>

54. ApacheHC/不満点
• HTTP/2は まだ 対応していない
• WebSocket対応もまだ

55. java.net.http

56. おさらい
• java.net.http / HttpClient
– Java11で正式APIになった
– HTTP/2対応
– WebSocket対応
– 同期/非同期 処理対応
– Reactive Streamとして
Request/Responseを処理
– Builderパターン

57. java.net.http
• Clientの作り方
もしくは
[Header]
GET /get HTTP/1.1
Content-Length: 0
Host: httpbin.org
User-Agent: Java-http-client/11.0.1
var client = HttpClient.newHttpClient();
var request = HttpRequest.newBuilder()
.uri(URI.create("https://http2.pro/api/v1"))
.build();
var resp = client.send(request,
HttpResponse.BodyHandlers.ofString(StandardCharsets.UTF_8));
System.out.println(resp.statusCode());
System.out.println(resp.body());
var client = HttpClient.newBuilder().build();
[Body]
{"http2":1,"protocol":"HT
TP¥/2.0","push":1,"user_a
gent":"Java-http-
client¥/11.0.1"}

58. java.net.http
• デフォルトは、
– HTTP/2を勝手にやってくれる
• サイトが対応していない場合はHTTP/1.1で通信
– Redirectは勝手にしてくれない
– GZip/Deflateは勝手に処理してくれない
• 便利なURIBuilderは存在しない

59. java.net.http
• ClientBuilder
– authenticator
– connectTimeout
– cookieHandler
– executor
– followRedirects
– priority
– proxy
– sslContext
– version
– sslParameters

60. java.net.http
• BodyHandlers
– ofString
– ofByteArray
– ofByteArrayConsumer
– ofFile
– ofFileDownload
– ofInputStream
– ofLines
– ofPublisher
– ...

61. java.net.http/redirect
• Redirectの設定
var client = HttpClient.newBuilder()
.followRedirects(HttpClient.Redirect.NORMAL)
.build();
NEVER Redirectしない
ALWAYS 常にRedirectする
NORMAL 常にRedirectする（HTTPS->HTTPは除く）

62. java.net.http/Header
• Request Headerの編集
var request = HttpRequest.newBuilder()
.header("Accept", "*/*")
.header("User-Agent", "JJUG/1.0")
.uri(URI.create("https://httpbin.org/get"))
.build();

63. java.net.http/POST
• POSTとBody送信
var bodyString = new Gson().toJson(Map.of("hello", "world"));
var client = HttpClient.newBuilder().build();
var request = HttpRequest.newBuilder()
.header("Content-Type", "application/json")
.POST(HttpRequest.BodyPublishers.ofString(bodyString))
.uri(URI.create("https://httpbin.org/post"))
.build();
var resp = client.send(
request,
HttpResponse.BodyHandlers.ofString(StandardCharsets.UTF_8));
System.out.println(resp.statusCode());
System.out.println(resp.body());

64. java.net.http
• BodyPublishers
– noBody
– ofString
– ofByteArray
– ofByteArrays
– ofFile
– ofInputStream
– ...

65. java.net.http/method
• 他のメソッド
– GET(), POST(), DELETE(), PUT()
– HEADやPATCHは？
• methodを使う
.method("HEAD", HttpRequest.BodyPublishers.noBody())
.method("PATCH", HttpRequest.BodyPublishers.ofString(bodyString))

66. java.net.http/async
• 非同期: client.sendAsync
var client = HttpClient.newBuilder().build();
var request = HttpRequest.newBuilder(URI.create("https://httpbin.org/get")).build();
CompletableFuture<HttpResponse<String>> future =
client.sendAsync(request,
HttpResponse.BodyHandlers.ofString(StandardCharsets.UTF_8));
// CompletableFutureなので処理を繋げる事ができる
future.thenApply(HttpResponse::body)
.exceptionally(e -> "Error!! :" + e.getMessage())
.thenAccept(System.out::println);
//future.get();

67. java.net.http/content-encoding
• BodySubscribers.mappingを使う
– ※JDKの不具合で動きません
https://bugs.openjdk.java.net/browse/JDK-8217264
private HttpResponse.BodySubscriber<InputStream> gzippedBodySubscriber(
HttpResponse.ResponseInfo responseInfo) {
// 本当はheaderのContent-Encodingを確認する
return HttpResponse.BodySubscribers.mapping(
HttpResponse.BodySubscribers.ofInputStream(),
this::decodeGzipStream);
}
private InputStream decodeGzipStream(InputStream gzippedStream) {
try {
return new GZIPInputStream(gzippedStream);
} catch (IOException ex) { throw new UncheckedIOException(ex); }
}
var resp = client.send(request, this::gzippedBodySubscriber);

68. java.net.http/content-encoding
• Workaround-1
var client = HttpClient.newBuilder().build();
var request = HttpRequest.newBuilder()
.uri(URI.create("https://httpbin.org/gzip"))
.build();
var resp = client.send(request, HttpResponse.BodyHandlers.ofInputStream());
InputStream in = resp.body();
if ("gzip".equals(resp.headers().firstValue("Content-Encoding").get())) {
in = new GZIPInputStream(resp.body());
}
System.out.println(IOUtils.toString(in, StandardCharsets.UTF_8));

69. java.net.http/content-encoding
• Workaround-2
var future = client.sendAsync(request, HttpResponse.BodyHandlers.ofInputStream())
.thenApply(resp -> {
String ce = resp.headers().firstValue("Content-Encoding").get();
if ("gzip".equals(ce)) {
try {
return new GZIPInputStream(resp.body());
} catch (IOException e) { throw new UncheckedIOException(e); }
}
return resp.body();
});
var in = future.get();
System.out.println(IOUtils.toString(in, StandardCharsets.UTF_8));

70. java.net.http/content-encoding
• Workaround others
https://stackoverflow.com/questions/53379087/wrapping-
bodysubscriberinputstream-in-gzipinputstream-leads-to-hang

71. java.net.http/custom handler
• 例: json
public static class JsonBodyHandler<T> implements HttpResponse.BodyHandler<T> {
private Class<T> type;
private JsonBodyHandler(Class<T> type) { this.type = type; }
public static <T> JsonBodyHandler<T> jsonBodyHandler(Class<T> type) {
return new JsonBodyHandler<>(type);
}
@Override
public HttpResponse.BodySubscriber<T> apply( HttpResponse.ResponseInfo info) {
return HttpResponse.BodySubscribers.mapping(
HttpResponse.BodySubscribers.ofString(StandardCharsets.UTF_8),
s -> new Gson().fromJson(s, this.type));
}
}
var resp = client.send(request, JsonBodyHandler.jsonBodyHandler(MyJson.class));
MyJson body = resp.body();

72. java.net.http/query-param, form-encoded
• 用意されていない
– 便利なライブラリが他にあるのでそれを利用して
BodyにStringとして渡す
– （例） Spring関連のLibrary
– （例） Apache HttpClient 😨

73. • デフォルトでは無効化されている
java.net.http/cookie
var cookieHandler = new CookieManager();
var client = HttpClient.newBuilder().cookieHandler(cookieHandler).build();
var u = URI.create("https://httpbin.org/cookies/set/hello/world");
var request1 = HttpRequest.newBuilder(u).build();
client.send(request1, HttpResponse.BodyHandlers.ofString());
var cookie = new HttpCookie("sushi", "tenpura");
cookie.setDomain(u.getHost());
cookie.setPath("/");
cookie.setVersion(0);
cookieHandler.getCookieStore().add(u, cookie);
var request2 =
HttpRequest.newBuilder(URI.create("https://httpbin.org/cookies")).build();
var resp2 = client.send(request2, HttpResponse.BodyHandlers.ofString());
Version0が⼤事
Version0 -> Netscape style
Version1 -> RFC2965/2109

74. java.net.http/basic auth
• Basic認証
– HttpUrlConnectionのサンプルと同じ
– 利用クラスも同じなのでそちらを参照
var client = HttpClient.newBuilder()
.authenticator(authenticator)
.build();

75. java.net.http/download
• Download
var client = HttpClient.newBuilder()
.followRedirects(HttpClient.Redirect.ALWAYS)
.build();
var u = URI.create("https://github.com/AdoptOpenJDK/openjdk11-
binaries/releases/download/jdk-11.0.3%2B7/OpenJDK11U-
jdk_x64_linux_hotspot_11.0.3_7.tar.gz");
var request = HttpRequest.newBuilder().uri(u).build();
Path f = Paths.get("/tmp/").resolve(Path.of(u.getPath()).getFileName());
var resp = client.send(request, HttpResponse.BodyHandlers.ofFile(f));
System.out.println(resp.statusCode());
System.out.println(f.toFile().length());

76. java.net.http/proxy with authentication
System.setProperty("jdk.http.auth.tunneling.disabledSchemes", "");
var proxySelector = ProxySelector.of(
InetSocketAddress.createUnresolved(PROXY_HOST, PROXY_PORT));
var client = HttpClient.newBuilder()
.proxy(proxySelector)
.authenticator(new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
if (getRequestorType() == RequestorType.PROXY) {
return new PasswordAuthentication(PROXY_USER, PROXY_PASS);
}
return null;
}
}).build();
var u = URI.create("https://httpbin.org/get");
var request1 = HttpRequest.newBuilder(u).build();
var resp = client.send(request1, HttpResponse.BodyHandlers.ofString());
https://www.oracle.com/technetwork/java/javase/8u111-relnotes-3124969.html
jdk8u111より
これが無いとhttpsのurlの
認証処理がskipされる
Proxyの時だけ認証

77. java.net.http/badSSL
• SSLContextを設定できるので、ApacheHCと同じ
var sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, new TrustManager[] { new X509TrustManager() {
public X509Certificate[] getAcceptedIssuers() { return null; }
public void checkClientTrusted(X509Certificate[] certs, String authType) { }
public void checkServerTrusted(X509Certificate[] certs, String authType) { }
} }, new SecureRandom());
var client = HttpClient.newBuilder().sslContext(sslContext).build();
var u = URI.create("https://expired.badssl.com/");
var request1 = HttpRequest.newBuilder(u).build();
var resp = client.send(request1, HttpResponse.BodyHandlers.ofString());

78. java.net.http/server-push
https://www.nginx.com/blog/nginx-1-13-9-http2-server-push/

79. java.net.http/server-push
var httpClient = HttpClient.newBuilder().version(HttpClient.Version.HTTP_2).build();
var pageRequest =
HttpRequest.newBuilder(URI.create("https://http2.golang.org/serverpush")).build();
AtomicInteger cnt = new AtomicInteger(1);
var futures = new CopyOnWriteArrayList<CompletableFuture<HttpResponse<String>>>();
HttpResponse.PushPromiseHandler<String> handler =
(initiatingRequest, pushPromiseRequest, acceptor) -> {
System.out.println("Promise request: " + pushPromiseRequest.uri());
var pushedFuture = acceptor.apply(HttpResponse.BodyHandlers.ofString());
pushedFuture = pushedFuture.thenApply(resp -> {
System.out.println("[" + cnt.getAndIncrement() + "] Pushed response: " + resp.uri());
return resp;
});
futures.add(pushedFuture);
}; applyPushPromise(
HttpRequest initiatingRequest,
HttpRequest pushPromiseRequest,
Function<HttpResponse.BodyHandler<String>,
CompletableFuture<HttpResponse<String>>> acceptor
)

80. java.net.http/server-push
var future = httpClient.sendAsync(
pageRequest,
HttpResponse.BodyHandlers.ofString(),
handler);
future.thenAccept(pageResponse -> {
System.out.println("Page response status code: " +
pageResponse.statusCode());
}).join();
var array = futures.toArray(new CompletableFuture[0]);
CompletableFuture.allOf(array).get();
Promise request: https://http2.golang.org/serverpush/static/jquery.min.js?1558076345232851844
Promise request: https://http2.golang.org/serverpush/static/godocs.js?1558076345232851844
Promise request: https://http2.golang.org/serverpush/static/playground.js?1558076345232851844
Promise request: https://http2.golang.org/serverpush/static/style.css?1558076345232851844
[1] Pushed response: https://http2.golang.org/serverpush/static/style.css?1558076345232851844
[2] Pushed response: https://http2.golang.org/serverpush/static/playground.js?1558076345232851844
[3] Pushed response: https://http2.golang.org/serverpush/static/godocs.js?1558076345232851844
Page response status code: 200
[4] Pushed response: https://http2.golang.org/serverpush/static/jquery.min.js?1558076345232851844

81. java.net.http/web-socket
var u = URI.create("wss://echo.websocket.org");
var client = HttpClient.newBuilder().build();
var listener = new WebSocket.Listener() {
public CompletionStage<?> onText(WebSocket webSocket,
CharSequence data, boolean last) {
System.out.println("receive:" + data + ", last=" + last);
return WebSocket.Listener.super.onText(webSocket, data, last);
}
};
WebSocket wsock = client.newWebSocketBuilder().buildAsync(u, listener).join();
wsock.sendText("hello world 1", false);
wsock.sendText("hello world 2", true);
TimeUnit.SECONDS.sleep(2);
wsock.sendClose(WebSocket.NORMAL_CLOSURE, "BYE");

82. java.net.http/debug
[class]
jdk.internal.net.http.common.Utils
jdk.internal.net.http.common.DebugLogger
jdk.internal.net.http.common.Log
jdk.internal.net.http.common.Logger
• システムプロパティの設定
jdk.internal.httpclient.debug=true
jdk.internal.httpclient.websocket.debug=true
jdk.internal.httpclient.hpack.debug=true

83. • もしくは
• もしくは
– LoggerName
java.net.http/debug
-Djava.net.HttpClient.log=
errors,requests,headers,frames[:control:data:window:all..],co
ntent,ssl,trace,channel
jdk.httpclient.HttpClient

84. java.net.http
• reactive streamの話をしていない?

85. java.net.http
• reactive streamの話をしていない?
– 今まで使っていたPublisher, SubScriberが
そうなのです。
public interface BodySubscriber<T> extends Flow.Subscriber<List<ByteBuffer>> {
CompletionStage<T> getBody();
void onSubscribe(Subscription subscription);
void onNext(List<ByteBuffer> item);
void onError(Throwable throwable);
void onComplete();
}
public interface BodyPublisher extends Flow.Publisher<ByteBuffer> {
long contentLength();
void subscribe(Subscriber<? super ByteBuffer> subscriber);
}

86. java.net.http
• もっといろいろな書き方が出来ます！！
– Javadocと公式サンプルを見て遊びましょう
続く（かも）