okhttp3

Enum Protocol

java.lang.Object

java.lang.Enum<Protocol>

okhttp3.Protocol

All Implemented Interfaces:

Serializable, Comparable<Protocol>

public enum Protocol
extends Enum<Protocol>

Protocols that OkHttp implements for ALPN selection.

Protocol vs Scheme

Despite its name, URL.getProtocol() returns the 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.

Enum Constant Summary

Enum Constants

Enum Constant and Description
H2_PRIOR_KNOWLEDGE Cleartext HTTP/2 with no "upgrade" round trip.
HTTP_1_0 An obsolete plaintext framing that does not use persistent sockets by default.
HTTP_1_1 A plaintext framing that includes persistent connections.
HTTP_2 The IETF's binary-framed protocol that includes header compression, multiplexing multiple requests on the same socket, and server-push.
QUIC 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.
SPDY_3 Deprecated. OkHttp has dropped support for SPDY. Prefer HTTP_2.

Method Summary

Modifier and Type	Method and Description
static Protocol	get(String protocol) Returns the protocol identified by protocol.
String	toString() Returns the string used to identify this protocol for ALPN, like "http/1.1", "spdy/3.1" or "h2".
static Protocol	valueOf(String name) Returns the enum constant of this type with the specified name.
static Protocol[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

HTTP_1_0

public static final Protocol HTTP_1_0

An obsolete plaintext framing that does not use persistent sockets by default.

HTTP_1_1

public static final Protocol HTTP_1_1

A plaintext framing that includes persistent connections.

This version of OkHttp implements RFC 7230, and tracks revisions to that spec.

SPDY_3

public static final Protocol SPDY_3

Deprecated. OkHttp has dropped support for SPDY. Prefer HTTP_2.

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.

HTTP_2

public static final Protocol HTTP_2

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 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 INADEQUATE_SECURITY.

H2_PRIOR_KNOWLEDGE

public static final Protocol H2_PRIOR_KNOWLEDGE

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 Also:

Starting HTTP/2 with Prior Knowledge

QUIC

public static final Protocol QUIC

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.

Method Detail

values

public static Protocol[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Protocol c : Protocol.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Protocol valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

get

public static Protocol get(String protocol)
                    throws IOException

Returns the protocol identified by protocol.

Throws:

IOException - if protocol is unknown.

toString

public String toString()

Returns the string used to identify this protocol for ALPN, like "http/1.1", "spdy/3.1" or "h2".

Overrides:

toString in class Enum<Protocol>

See Also:

IANA tls-extensiontype-values