okhttp3.Protocol Maven / Gradle / Ivy
/*
* Copyright (C) 2014 Square, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package okhttp3;
import java.io.IOException;
/**
* Protocols that OkHttp implements for ALPN selection.
*
* Protocol vs Scheme
Despite its name, {@link java.net.URL#getProtocol()} returns the
* {@linkplain java.net.URI#getScheme() scheme} (http, https, etc.) of the URL, not the protocol
* (http/1.1, spdy/3.1, etc.). OkHttp uses the word protocol to identify how HTTP messages
* are framed.
*/
public enum Protocol {
/**
* An obsolete plaintext framing that does not use persistent sockets by default.
*/
HTTP_1_0("http/1.0"),
/**
* A plaintext framing that includes persistent connections.
*
* This version of OkHttp implements RFC
* 7230, and tracks revisions to that spec.
*/
HTTP_1_1("http/1.1"),
/**
* Chromium's binary-framed protocol that includes header compression, multiplexing multiple
* requests on the same socket, and server-push. HTTP/1.1 semantics are layered on SPDY/3.
*
*
Current versions of OkHttp do not support this protocol.
*
* @deprecated OkHttp has dropped support for SPDY. Prefer {@link #HTTP_2}.
*/
SPDY_3("spdy/3.1"),
/**
* The IETF's binary-framed protocol that includes header compression, multiplexing multiple
* requests on the same socket, and server-push. HTTP/1.1 semantics are layered on HTTP/2.
*
*
HTTP/2 requires deployments of HTTP/2 that use TLS 1.2 support {@linkplain
* CipherSuite#TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256} , present in Java 8+ and Android 5+. Servers
* that enforce this may send an exception message including the string {@code
* INADEQUATE_SECURITY}.
*/
HTTP_2("h2"),
/**
* Cleartext HTTP/2 with no "upgrade" round trip. This option requires the client to have prior
* knowledge that the server supports cleartext HTTP/2.
*
* @see Starting HTTP/2 with Prior
* Knowledge
*/
H2_PRIOR_KNOWLEDGE("h2_prior_knowledge"),
/**
* QUIC (Quick UDP Internet Connection) is a new multiplexed and secure transport atop UDP,
* designed from the ground up and optimized for HTTP/2 semantics.
* HTTP/1.1 semantics are layered on HTTP/2.
*
*
QUIC is not natively supported by OkHttp, but provided to allow a theoretical
* interceptor that provides support.
*/
QUIC("quic");
private final String protocol;
Protocol(String protocol) {
this.protocol = protocol;
}
/**
* Returns the protocol identified by {@code protocol}.
*
* @throws IOException if {@code protocol} is unknown.
*/
public static Protocol get(String protocol) throws IOException {
// Unroll the loop over values() to save an allocation.
if (protocol.equals(HTTP_1_0.protocol)) return HTTP_1_0;
if (protocol.equals(HTTP_1_1.protocol)) return HTTP_1_1;
if (protocol.equals(H2_PRIOR_KNOWLEDGE.protocol)) return H2_PRIOR_KNOWLEDGE;
if (protocol.equals(HTTP_2.protocol)) return HTTP_2;
if (protocol.equals(SPDY_3.protocol)) return SPDY_3;
if (protocol.equals(QUIC.protocol)) return QUIC;
throw new IOException("Unexpected protocol: " + protocol);
}
/**
* Returns the string used to identify this protocol for ALPN, like "http/1.1", "spdy/3.1" or
* "h2".
*
* @see IANA
* tls-extensiontype-values
*/
@Override public String toString() {
return protocol;
}
}