Retrofit 2 is a major release focused on extensibility. The API changes are numerous but solve shortcomings of the previous version and provide a path for future enhancement.
Because the release includes breaking API changes, we're changing the project's package name from
retrofit
to retrofit2
. This should make it possible for large applications and libraries to
migrate incrementally. The Maven group ID is now com.squareup.retrofit2
. For an explanation of
this strategy, see Jake Wharton's post, Java Interoperability Policy for Major Version
Updates.
-
Service methods return
Call<T>
. This allows them to be executed synchronously or asynchronously using the same method definition. ACall
instance represents a single request/response pair so it can only be used once, but you canclone()
it for re-use. Invokingcancel()
will cancel in-flight requests or prevent the request from even being performed if it has not already. -
Multiple converters for multiple serialization formats. API calls returning different formats (like JSON, protocol buffers, and plain text) no longer need to be separated into separate service interfaces. Combine them together and add multiple converters. Converters are chosen based on the response type you declare. Gson is no longer included by default, so you will always need to add a converter for any serialization support. OkHttp's
RequestBody
andResponseBody
types can always be used without adding one, however. -
Call adapters allow different execution mechanisms. While
Call
is the built-in mechanism, support for additional ones can be added similar to how different converters can be added. RxJava'sObservable
support has moved into a separate artifact as a result, and support for Java 8'sCompletableFuture
and Guava'sListenableFuture
are also provided as additional artifacts. -
Generic response type includes HTTP information and deserialized body. You no longer have to choose between the deserialized body and reading HTTP information. Every
Call
automatically receives both via theResponse<T>
type and the RxJava, Guava, and Java 8 call adapters also support it. -
@Url for hypermedia-like APIs. When your API returns links for pagination, additional resources, or updated content they can now be used with a service method whose first parameter is annotated with
@Url
.
Changes from beta 4:
- New:
RxJavaCallAdapterFactory
now supports service methods which returnCompletable
which ignores and discards response bodies, if any. - New:
RxJavaCallAdapterFactory
supports supplying a defaultScheduler
which will be used forsubscribeOn
on returnedObservable
,Single
, andCompletable
instances. - New:
MoshiConverterFactory
supports creating an instance which uses lenient parsing. - New:
@Part
can omit the part name and use OkHttp'sMultipartBody.Part
type for supplying parts. This lets you customize the headers, name, and filename and provide the part body in a single argument. - The
BaseUrl
interface and support for changeable base URLs was removed. This functionality can be done using an OkHttp interceptor and a sample showcasing it was added. Response.isSuccess()
was renamed toResponse.isSuccessful()
for parity with the name of OkHttp's version of that method.- Fix: Throw a more appropriate exception with a message when a resolved url (base URL + relative URL) is malformed.
- Fix:
GsonConverterFactory
now honors settings on theGson
instance (like leniency). - Fix:
ScalarsConverterFactory
now supports primitive scalar types in addition to boxed for response body parsing. - Fix:
Retrofit.callbackExecutor()
may now return an executor even when one was not explicitly provided. This allows customCallAdapter.Factory
implementations to use it when triggering callbacks to ensure they happen on the appropriate thread for the platform (e.g., Android).
- New:
Call
instance is now passed to bothonResponse
andonFailure
methods ofCallback
. This aids in detecting whenonFailure
is called as a result ofCall.cancel()
by checkingCall.isCanceled()
. - New:
Call.request()
returns (optionally creating) theRequest
object for the call. Note: If this is called beforeCall.execute()
orCall.enqueue()
this will do relatively expensive work synchronously. Doing so in performance-critical sections (like on the Android main thread) should be avoided. - New: Support for the release version of OkHttp 3.0 and newer.
- New:
adapter-guava
module provides aCallAdapter.Factory
for Guava'sListenableFuture
. - New:
adapter-java8
module provides aCallAdapter.Factory
for Java 8'sCompleteableFuture
. - New:
ScalarsConverterFactory
(fromconverter-scalars
module) now supports parsing response bodies into eitherString
, the 8 primitive types, or the 8 boxed primitive types. - New: Automatic support for sending callbacks to the iOS main thread when running via RoboVM.
- New: Method annotations are now passed to the factory for request body converters. This allows converters to alter the structure of both request bodies and response bodies with a single method-level annotation.
- Each converter has been moved to its own package under
retrofit2.converter.<name>
. This prevents type collisions when many converters are simultaneously in use. - Fix: Exceptions thrown when unable to locate a
CallAdapter.Factory
for a method return type now correctly list theCallAdapter.Factory
instances checked. - Fix: Ensure default methods on service interfaces can be invoked.
- Fix: Correctly resolve the generic parameter types of collection interfaces when subclasses of those collections are used as method parameters.
- Fix: Do not encode
/
characters in@Path
replacements whenencoded = true
.
- New: All classes have been migrated to the
retrofit2.*
package name. The Maven groupId is nowcom.squareup.retrofit2
. This is in accordance with the Java Interoperability Policy for Major Version Updates. With this change Retrofit 2.x can coexiest with Retrofit 1.x in the same project. - New: Update to use the OkHttp 3 API and OkHttp 3.0.0-RC1 or newer is now required. Similar to the previous
point, OkHttp has a new package name (
okhttp3.*
) and Maven groupId (com.squareup.okhttp3
) which allow it to coexist with OkHttp 2.x in the same project. - New: String converters allow for custom serialization of parameters that end up as strings (such as
@Path
,@Query
,@Header
, etc.).Converter.Factory
has a newstringConverter
method which receives the parameter type and annotations and can return a converter for that type. This allows providing custom rendering of types likeDate
,User
, etc. to a string before being used for its purpose. A default converter will calltoString()
for any type which retains the mimics the previous behavior. - New: OkHttp's
Call.Factory
type is now used as the HTTP client rather than using theOkHttpClient
type directly (OkHttpClient
does implementCall.Factory
). AcallFactory
method has been added to bothRetrofit.Builder
andRetrofit
to allow supplying alternate implementations of an HTTP client. Theclient(OkHttpClient)
method onRetrofit.Builder
still exists as a convenience. - New:
isExecuted()
method returns whether aCall
has been synchronously or asynchronously executed. - New:
isCanceled()
method returns whether aCall
has been canceled. Use this inonFailure
to determine whether the callback was invoked from cancellation or actual transport failure. - New:
converter-scalars
module provides aConverter.Factory
for convertingString
, the 8 primitive types, and the 8 boxed primitive types astext/plain
bodies. Install this before your normal converter to avoid passing these simple scalars through, for example, a JSON converter. - New:
Converter.Factory
methods now receive aRetrofit
instance which also now has methods for querying the next converter for a given type. This allows implementations to delegate to others and provide additional behavior without complete reimplementation. - New:
@OPTIONS
annotation more easily allows for making OPTIONS requests. - New:
@Part
annotation now supportsList
and array types. - New: The
@Url
annotation now allows usingjava.net.URI
orandroid.net.Uri
(in addition toString
) as parameter types for providing relative or absolute endpoint URLs dynamically. - New: The
retrofit-mock
module has been rewritten with a newBehaviorDelegate
class for implementing fake network behavior in a local mock implementation of your service endpoints. Documentation and more tests are forthcoming, but theSimpleMockService
demonstrates its use for now. - Fix: Forbid Retrofit's
Response
type and OkHttp'sResponse
type as the response body type given to aCall
(i.e.,Call<Response>
). OkHttp'sResponseBody
type is the correct one to use when the raw body contents are desired. - Fix: The Gson converter now respects settings on the supplied
Gson
instance (such asserializeNulls
). This requires Gson 2.4 or newer. - The Wire converter has been updated to the Wire 2.0 API.
- The change in 2.0.0-beta2 which provided the
Retrofit
instance to theonResponse
callback ofCallback
has been reverted. There are too many edge cases around providing theRetrofit
object in order to allow deserialization of the error body. To accommodate this use case, pass around theRetrofit
response manually or implement a customCallAdapter.Factory
does so automatically.
- New: Using a response type of
Void
(e.g.,Call<Void>
) will ignore and discard the response body. This can be used when there will be no response body (such as in a 201 response) or whenever the body is not needed.@Head
requests are now forced to use this as their response type. - New:
validateEagerly()
method onRetrofit.Builder
will verify the correctness of all service methods on calls tocreate()
instead of lazily validating on first use. - New:
Converter
is now parameterized over both 'from' and 'to' types with a singleconvert
method.Converter.Factory
is now an abstract class and has factory methods for both request body and response body. - New:
Converter.Factory
andCallAdapter.Factory
now receive the method annotations when being created for a return/response type and the parameter annotations when being created for a parameter type. - New:
callAdapter()
method onRetrofit
allows querying aCallAdapter
for a given type. ThenextCallAdapter()
method allows delegating to anotherCallAdapter
from within aCallAdapter.Factory
. This is useful for composing call adapters to incrementally build up behavior. - New:
requestConverter()
andresponseConverter()
methods onRetrofit
allow querying aConverter
for a given type. - New:
onResponse
method inCallback
now receives theRetrofit
instance. Combined with theresponseConverter()
method onRetrofit
, this provides a way of deserializing an error body onResponse
. See theDeserializeErrorBody
sample for an example. - New: The
MoshiConverterFactory
has been updated for its v1.0.0. - Fix: Using
ResponseBody
for the response type orRequestBody
for a parameter type is now correctly identified. Previously these types would erroneously be passed to the supplied converter. - Fix: The encoding of
@Path
values has been corrected to conform to OkHttp'sHttpUrl
. - Fix: Use form-data content disposition subtype for
@Multipart
. - Fix:
Observable
andSingle
-based execution of requests now behave synchronously (and thus requiressubscribeOn()
for running in the background). - Fix: Correct
GsonConverterFactory
to honor the configuration of theGson
instances (such as not serializing null values, the default).
- New:
Call
encapsulates a single request/response HTTP call. A call can by run synchronously viaexecute()
or asynchronously viaenqueue()
and can be canceled withcancel()
. - New:
Response
is now parameterized and includes the deserialized body object. - New:
@Url
parameter annotation allows passing a complete URL for an endpoint. - New: OkHttp is now required as a dependency. Types like
TypedInput
andTypedOutput
(and its implementations),Request
, andHeader
have been replaced with OkHttp types likeRequestBody
,ResponseBody
, andHeaders
. - New:
CallAdapter
(andFactory
) provides extension point for supporting multiple execution mechanisms. An RxJava implementation is provided by a sibling module. - New:
Converter
(andFactory
) provides extension point for supporting multiple serialization mechanisms. Gson, Jackson, Moshi, Protobuf, Wire, and SimpleXml implementations are provided by sibling modules. - Fix: A lot of things.
- Hello Droidcon NYC 2015!
- Update to OkHttp 2.x's native API. If you are using OkHttp you must use version 2.0 or newer (the latest
is 2.2 at time of writing) and you no longer need to use the
okhttp-urlconnection
shim. - New: Allow disabling Simple XML Framework's strict parsing.
- New:
@Header
now accepts aList
or array for a type. - New:
@Field
and@FieldMap
now have options for enabling or disabling URL encoding of names and values. - Fix: Remove query parameters from thread name when running background requests for asynchronous use.
- Update to RxJava 1.0. This comes with the project's 'groupId' change from
com.netflix.rxjava
toio.reactivex
which is why the minor version was bumped.
- Fix: Correctly log
null
request arguments forHEADERS_AND_ARGS
log level.
- New:
RetrofitError
'sgetKind()
now disambiguates the type of error represented. - New:
HEADERS_AND_ARGS
log level displays parameters passed to method invocation along with normal header list. - New:
@Part
and@PartMap
now support specifying theContent-Transfer-Encoding
of their respective values. - New:
@Path
,@Query
, and@QueryMap
now have options for enabling or disabling URL encoding on names (where appropriate) and values. @Header
now accepts all object types, invokingString.valueOf
when neccesary.- Attempting to use a
@Path
replacement block ({name}
) in a query parameter now suggested@Query
in the exception message. - Fix: Correct NPE when
Content-Type
override is specified on requests without a body. - Fix:
WireConverter
now correctly throwsConversionException
on incorrect MIME types for parity withProtoConverter
. - Fix: Include
Content-Type
on AppEngine requests. - Fix: Account for NPE on AppEngine when the response URL was not automatically populated in certain cases.
- Fix:
MockRestAdapter
's RxJava support now correctly schedules work on the HTTP executor, specifically when chaining multiple requests together. - Experimental RxJava support updated for v0.20.
- Fix: Add any explicitly-specified 'Content-Type' header (via annotation or param) to the request even if there is no request body (e.g., DELETE).
- Fix: Include trailing CRLF in multi-part uploads to work around a bug in .NET MVC 4 parsing.
- Fix: Allow
null
mock exception bodies and use the success type from the declared service interface.
- New:
@Streaming
on aResponse
type will skip buffering the body to abyte[]
before delivering. - When using OkHttp, version 1.6.0 or newer (including 2.0.0+) is now required.
- The absence of a response body and an empty body are now differentiated in the log messages.
- Fix: If set, the
RequestInterceptor
is now applied at the time ofObservable
subscription rather than at the time of its creation. - Fix:
Callback
subtypes are now supported when usingMockRestAdapter
. - Fix:
RetrofitError
now contains a useful message indicating the reason for the failure. - Fix: Exceptions thrown when parsing the response type of the interface are now properly propagated.
- Fix: Calling
Response#getBody
whennull
body now correctly returns instead of throwing an NPE. - Experimental RxJava support updated for v0.19.
- The
Content-Type
andContent-Length
headers are no longer automatically added to the header list on theRequest
object. This reverts erroneous behavior added in v1.5.0. CustomClient
implementations should revert to adding these headers based on theTypedInput
body of theRequest
.
- New:
@PartMap
annotation accepts aMap
of key/value pairs for multi-part. - Fix:
MockRestAdpater
uses theErrorHandler
from its parentRestAdapter
. - Experimental RxJava support updated for v0.18 and is now lazily initialized.
- New: Support for AppEngine's URL Fetch HTTP client.
- New: Multipart requests of unknown length are now supported.
- New: HTTP
Content-Type
can be overridden with a method-level or paramter header annotation. - New: Exceptions from malformed interface methods now include detailed information.
- Fix: Support empty HTTP response status reason.
- If an
ErrorHandler
is supplied it will be invoked forCallback
andObservable
methods. - HTTP
PATCH
method usingHttpUrlConnection
is no longer supported. Add the OkHttp jar to your project if you need this behavior. - Custom
Client
implementations should no longer setContent-Type
orContent-Length
headers based on theTypedInput
body of theRequest
. These headers will now be added automatically as part of the standardRequest
header list.
- Fix:
@QueryMap
,@EncodedFieldMap
, and@FieldMap
now correctly detectMap
-based parameter types.
- New:
@Query
and@EncodedQuery
now acceptList
or arrays for multiple values. - New:
@QueryMap
and@EncodedQueryMap
accept aMap
of key/value pairs for query parameters. - New:
@Field
now acceptsList
or arrays for multiple values. - New:
@FieldMap
accepts aMap
of name/value pairs for form URL-encoded request bodies. - New:
Endpoint
replacesServer
as the representation of the remote API root. TheEndpoints
utility class contains factories methods for creating instances.Server
andChangeableServer
are now deprecated. SimpleXmlConverter
andJacksonConverter
now have a default constructor.Response
now includes the URL.- Fix: Hide references to optional classes to prevent over-eager class verifiers from complaining (e.g., Dalvik).
- Fix: Properly detect and reject interfaces which extend from other interfaces.
- New: Converter module for SimpleXML.
- New: Mock module which allows simulating real network behavior for local service interface implementations. See 'mock-github-client' example for a demo.
- New: RxJava
Observable
support! Declare a return type ofObservable<Foo>
on your service interfaces to automatically get an observable for that request. (Experimental API) - Fix: Use
ObjectMapper
's type factory when deserializing (Jackson converter). - Multipart POST requests now stream their individual part bodies.
- Log chunking to 4000 characters now only happens on the Android platform.
- Fix: Respect connection and read timeouts on supplied
OkHttpClient
instances. - Fix: Ensure connection is closed on non-200 responses.
- New: Converter for Wire protocol buffers!
- New: Additional first-party converters for Jackson and Protocol Buffers! These are provided
as separate modules that you can include and pass to
RestAdapter.Builder
'ssetConverter
. - New:
@EncodedPath
and@EncodedQuery
annotations allow provided path and query params that are already URL-encoded. - New:
@PATCH
HTTP method annotation. - Fix: Properly support custom HTTP method annotations in
UrlConnectionClient
. - Fix: Apply
RequestInterceptor
during method invocation rather than at request execution time. - Change
setDebug
tosetLogLevel
onRestAdapter
andRestAdapter.Builder
and provide two levels of logging viaLogLevel
. - Query parameters can now be added in a request interceptor.
- Fix: Ensure
@Headers
-defined headers are correctly added to requests. - Fix: Supply reasonable connection and read timeouts for default clients.
- Fix: Allow passing
null
for a@Part
-annotated argument to remove it from the multipart request body.
- Introduce
RequestInterceptor
to replaceRequestHeaders
. An interceptor provided to theRestAdapter.Builder
will be called for every request and allow setting both headers and additional path parameter replacements. - Add
ErrorHandler
for customizing the exceptions which are thrown when synchronous methods return non-200 error codes. - Properly parse responses which erroneously omit the "Content-Type" header.
- Allow uppercase letters in path replacement identifiers.
- Fix: Static query parameters in the URL are now correctly appended with a separating '?'.
- Fix: Explicitly allow or forbid
null
as a value for method parameters.@Path
- Forbidden@Query
- Allowed@Field
- Allowed@Part
- Forbidden@Body
- Forbidden@Header
- Allowed
- Fix: Correct bad regex behavior on Android.
Initial release.