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RSocket
This section describes Spring Framework’s support for the RSocket protocol.
Overview
RSocket is an application protocol for multiplexed, duplex communication over TCP, WebSocket, and other byte stream transports, using one of the following interaction models:
-
Request-Response
— send one message and receive one back. -
Request-Stream
— send one message and receive a stream of messages back. -
Channel
— send streams of messages in both directions. -
Fire-and-Forget
— send a one-way message.
Once the initial connection is made, the "client" vs "server" distinction is lost as both sides become symmetrical and each side can initiate one of the above interactions. This is why in the protocol calls the participating sides "requester" and "responder" while the above interactions are called "request streams" or simply "requests".
These are the key features and benefits of the RSocket protocol:
-
Reactive Streams semantics across network boundary — for streaming requests such as
Request-Stream
andChannel
, back pressure signals travel between requester and responder, allowing a requester to slow down a responder at the source, hence reducing reliance on network layer congestion control, and the need for buffering at the network level or at any level. -
Request throttling — this feature is named "Leasing" after the
LEASE
frame that can be sent from each end to limit the total number of requests allowed by other end for a given time. Leases are renewed periodically. -
Session resumption — this is designed for loss of connectivity and requires some state to be maintained. The state management is transparent for applications, and works well in combination with back pressure which can stop a producer when possible and reduce the amount of state required.
-
Fragmentation and re-assembly of large messages.
-
Keepalive (heartbeats).
RSocket has implementations in multiple languages. The Java library is built on Project Reactor, and Reactor Netty for the transport. That means signals from Reactive Streams Publishers in your application propagate transparently through RSocket across the network.
The Protocol
One of the benefits of RSocket is that it has well defined behavior on the wire and an easy to read specification along with some protocol extensions. Therefore it is a good idea to read the spec, independent of language implementations and higher level framework APIs. This section provides a succinct overview to establish some context.
Connecting
Initially a client connects to a server via some low level streaming transport such
as TCP or WebSocket and sends a SETUP
frame to the server to set parameters for the
connection.
The server may reject the SETUP
frame, but generally after it is sent (for the client)
and received (for the server), both sides can begin to make requests, unless SETUP
indicates use of leasing semantics to limit the number of requests, in which case
both sides must wait for a LEASE
frame from the other end to permit making requests.
Making Requests
Once a connection is established, both sides may initiate a request through one of the
frames REQUEST_RESPONSE
, REQUEST_STREAM
, REQUEST_CHANNEL
, or REQUEST_FNF
. Each of
those frames carries one message from the requester to the responder.
The responder may then return PAYLOAD
frames with response messages, and in the case
of REQUEST_CHANNEL
the requester may also send PAYLOAD
frames with more request
messages.
When a request involves a stream of messages such as Request-Stream
and Channel
,
the responder must respect demand signals from the requester. Demand is expressed as a
number of messages. Initial demand is specified in REQUEST_STREAM
and
REQUEST_CHANNEL
frames. Subsequent demand is signaled via REQUEST_N
frames.
Each side may also send metadata notifications, via the METADATA_PUSH
frame, that do not
pertain to any individual request but rather to the connection as a whole.
Message Format
RSocket messages contain data and metadata. Metadata can be used to send a route, a
security token, etc. Data and metadata can be formatted differently. Mime types for each
are declared in the SETUP
frame and apply to all requests on a given connection.
While all messages can have metadata, typically metadata such as a route are per-request
and therefore only included in the first message on a request, i.e. with one of the frames
REQUEST_RESPONSE
, REQUEST_STREAM
, REQUEST_CHANNEL
, or REQUEST_FNF
.
Protocol extensions define common metadata formats for use in applications:
-
Composite Metadata-- multiple, independently formatted metadata entries.
-
Routing — the route for a request.
Java Implementation
The Java implementation for RSocket is built on
Project Reactor. The transports for TCP and WebSocket are
built on Reactor Netty. As a Reactive Streams
library, Reactor simplifies the job of implementing the protocol. For applications it is
a natural fit to use Flux
and Mono
with declarative operators and transparent back
pressure support.
The API in RSocket Java is intentionally minimal and basic. It focuses on protocol features and leaves the application programming model (e.g. RPC codegen vs other) as a higher level, independent concern.
The main contract
io.rsocket.RSocket
models the four request interaction types with Mono
representing a promise for a
single message, Flux
a stream of messages, and io.rsocket.Payload
the actual
message with access to data and metadata as byte buffers. The RSocket
contract is used
symmetrically. For requesting, the application is given an RSocket
to perform
requests with. For responding, the application implements RSocket
to handle requests.
This is not meant to be a thorough introduction. For the most part, Spring applications will not have to use its API directly. However it may be important to see or experiment with RSocket independent of Spring. The RSocket Java repository contains a number of sample apps that demonstrate its API and protocol features.
Spring Support
The spring-messaging
module contains the following:
-
RSocketRequester — fluent API to make requests through an
io.rsocket.RSocket
with data and metadata encoding/decoding. -
Annotated Responders —
@MessageMapping
annotated handler methods for responding.
The spring-web
module contains Encoder
and Decoder
implementations such as Jackson
CBOR/JSON, and Protobuf that RSocket applications will likely need. It also contains the
PathPatternParser
that can be plugged in for efficient route matching.
Spring Boot 2.2 supports standing up an RSocket server over TCP or WebSocket, including
the option to expose RSocket over WebSocket in a WebFlux server. There is also client
support and auto-configuration for an RSocketRequester.Builder
and RSocketStrategies
.
See the
RSocket section
in the Spring Boot reference for more details.
Spring Security 5.2 provides RSocket support.
Spring Integration 5.2 provides inbound and outbound gateways to interact with RSocket clients and servers. See the Spring Integration Reference Manual for more details.
Spring Cloud Gateway supports RSocket connections.
RSocketRequester
RSocketRequester
provides a fluent API to perform RSocket requests, accepting and
returning objects for data and metadata instead of low level data buffers. It can be used
symmetrically, to make requests from clients and to make requests from servers.
Client Requester
To obtain an RSocketRequester
on the client side is to connect to a server which involves
sending an RSocket SETUP
frame with connection settings. RSocketRequester
provides a
builder that helps to prepare an io.rsocket.core.RSocketConnector
including connection
settings for the SETUP
frame.
This is the most basic way to connect with default settings:
-
Java
-
Kotlin
RSocketRequester requester = RSocketRequester.builder().tcp("localhost", 7000);
URI url = URI.create("https://example.org:8080/rsocket");
RSocketRequester requester = RSocketRequester.builder().webSocket(url);
val requester = RSocketRequester.builder().tcp("localhost", 7000)
URI url = URI.create("https://example.org:8080/rsocket");
val requester = RSocketRequester.builder().webSocket(url)
The above does not connect immediately. When requests are made, a shared connection is established transparently and used.
Connection Setup
RSocketRequester.Builder
provides the following to customize the initial SETUP
frame:
-
dataMimeType(MimeType)
— set the mime type for data on the connection. -
metadataMimeType(MimeType)
— set the mime type for metadata on the connection. -
setupData(Object)
— data to include in theSETUP
. -
setupRoute(String, Object…)
— route in the metadata to include in theSETUP
. -
setupMetadata(Object, MimeType)
— other metadata to include in theSETUP
.
For data, the default mime type is derived from the first configured Decoder
. For
metadata, the default mime type is
composite metadata which allows multiple
metadata value and mime type pairs per request. Typically both don’t need to be changed.
Data and metadata in the SETUP
frame is optional. On the server side,
@ConnectMapping methods can be used to handle the start of a
connection and the content of the SETUP
frame. Metadata may be used for connection
level security.
Strategies
RSocketRequester.Builder
accepts RSocketStrategies
to configure the requester.
You’ll need to use this to provide encoders and decoders for (de)-serialization of data and
metadata values. By default only the basic codecs from spring-core
for String
,
byte[]
, and ByteBuffer
are registered. Adding spring-web
provides access to more that
can be registered as follows:
-
Java
-
Kotlin
RSocketStrategies strategies = RSocketStrategies.builder()
.encoders(encoders -> encoders.add(new Jackson2CborEncoder()))
.decoders(decoders -> decoders.add(new Jackson2CborDecoder()))
.build();
RSocketRequester requester = RSocketRequester.builder()
.rsocketStrategies(strategies)
.tcp("localhost", 7000);
val strategies = RSocketStrategies.builder()
.encoders { it.add(Jackson2CborEncoder()) }
.decoders { it.add(Jackson2CborDecoder()) }
.build()
val requester = RSocketRequester.builder()
.rsocketStrategies(strategies)
.tcp("localhost", 7000)
RSocketStrategies
is designed for re-use. In some scenarios, e.g. client and server in
the same application, it may be preferable to declare it in Spring configuration.
Client Responders
RSocketRequester.Builder
can be used to configure responders to requests from the
server.
You can use annotated handlers for client-side responding based on the same infrastructure that’s used on a server, but registered programmatically as follows:
-
Java
-
Kotlin
RSocketStrategies strategies = RSocketStrategies.builder()
.routeMatcher(new PathPatternRouteMatcher()) (1)
.build();
SocketAcceptor responder =
RSocketMessageHandler.responder(strategies, new ClientHandler()); (2)
RSocketRequester requester = RSocketRequester.builder()
.rsocketConnector(connector -> connector.acceptor(responder)) (3)
.tcp("localhost", 7000);
1 | Use PathPatternRouteMatcher , if spring-web is present, for efficient
route matching. |
2 | Create a responder from a class with @MessageMapping and/or @ConnectMapping methods. |
3 | Register the responder. |
val strategies = RSocketStrategies.builder()
.routeMatcher(PathPatternRouteMatcher()) (1)
.build()
val responder =
RSocketMessageHandler.responder(strategies, new ClientHandler()); (2)
val requester = RSocketRequester.builder()
.rsocketConnector { it.acceptor(responder) } (3)
.tcp("localhost", 7000)
1 | Use PathPatternRouteMatcher , if spring-web is present, for efficient
route matching. |
2 | Create a responder from a class with @MessageMapping and/or @ConnectMapping methods. |
3 | Register the responder. |
Note the above is only a shortcut designed for programmatic registration of client
responders. For alternative scenarios, where client responders are in Spring configuration,
you can still declare RSocketMessageHandler
as a Spring bean and then apply as follows:
-
Java
-
Kotlin
ApplicationContext context = ... ;
RSocketMessageHandler handler = context.getBean(RSocketMessageHandler.class);
RSocketRequester requester = RSocketRequester.builder()
.rsocketConnector(connector -> connector.acceptor(handler.responder()))
.tcp("localhost", 7000);
import org.springframework.beans.factory.getBean
val context: ApplicationContext = ...
val handler = context.getBean<RSocketMessageHandler>()
val requester = RSocketRequester.builder()
.rsocketConnector { it.acceptor(handler.responder()) }
.tcp("localhost", 7000)
For the above you may also need to use setHandlerPredicate
in RSocketMessageHandler
to
switch to a different strategy for detecting client responders, e.g. based on a custom
annotation such as @RSocketClientResponder
vs the default @Controller
. This
is necessary in scenarios with client and server, or multiple clients in the same
application.
See also Annotated Responders, for more on the programming model.
Advanced
RSocketRequesterBuilder
provides a callback to expose the underlying
io.rsocket.core.RSocketConnector
for further configuration options for keepalive
intervals, session resumption, interceptors, and more. You can configure options
at that level as follows:
-
Java
-
Kotlin
RSocketRequester requester = RSocketRequester.builder()
.rsocketConnector(connector -> {
// ...
})
.tcp("localhost", 7000);
val requester = RSocketRequester.builder()
.rsocketConnector {
//...
}
.tcp("localhost", 7000)
Server Requester
To make requests from a server to connected clients is a matter of obtaining the requester for the connected client from the server.
In Annotated Responders, @ConnectMapping
and @MessageMapping
methods support an
RSocketRequester
argument. Use it to access the requester for the connection. Keep in
mind that @ConnectMapping
methods are essentially handlers of the SETUP
frame which
must be handled before requests can begin. Therefore, requests at the very start must be
decoupled from handling. For example:
-
Java
-
Kotlin
@ConnectMapping
Mono<Void> handle(RSocketRequester requester) {
requester.route("status").data("5")
.retrieveFlux(StatusReport.class)
.subscribe(bar -> { (1)
// ...
});
return ... (2)
}
1 | Start the request asynchronously, independent from handling. |
2 | Perform handling and return completion Mono<Void> . |
@ConnectMapping
suspend fun handle(requester: RSocketRequester) {
GlobalScope.launch {
requester.route("status").data("5").retrieveFlow<StatusReport>().collect { (1)
// ...
}
}
/// ... (2)
}
1 | Start the request asynchronously, independent from handling. |
2 | Perform handling in the suspending function. |
Requests
-
Java
-
Kotlin
ViewBox viewBox = ... ;
Flux<AirportLocation> locations = requester.route("locate.radars.within") (1)
.data(viewBox) (2)
.retrieveFlux(AirportLocation.class); (3)
1 | Specify a route to include in the metadata of the request message. |
2 | Provide data for the request message. |
3 | Declare the expected response. |
val viewBox: ViewBox = ...
val locations = requester.route("locate.radars.within") (1)
.data(viewBox) (2)
.retrieveFlow<AirportLocation>() (3)
1 | Specify a route to include in the metadata of the request message. |
2 | Provide data for the request message. |
3 | Declare the expected response. |
The interaction type is determined implicitly from the cardinality of the input and
output. The above example is a Request-Stream
because one value is sent and a stream
of values is received. For the most part you don’t need to think about this as long as the
choice of input and output matches an RSocket interaction type and the types of input and
output expected by the responder. The only example of an invalid combination is many-to-one.
The data(Object)
method also accepts any Reactive Streams Publisher
, including
Flux
and Mono
, as well as any other producer of value(s) that is registered in the
ReactiveAdapterRegistry
. For a multi-value Publisher
such as Flux
which produces the
same types of values, consider using one of the overloaded data
methods to avoid having
type checks and Encoder
lookup on every element:
data(Object producer, Class<?> elementClass);
data(Object producer, ParameterizedTypeReference<?> elementTypeRef);
The data(Object)
step is optional. Skip it for requests that don’t send data:
-
Java
-
Kotlin
Mono<AirportLocation> location = requester.route("find.radar.EWR"))
.retrieveMono(AirportLocation.class);
import org.springframework.messaging.rsocket.retrieveAndAwait
val location = requester.route("find.radar.EWR")
.retrieveAndAwait<AirportLocation>()
Extra metadata values can be added if using
composite metadata (the default) and if the
values are supported by a registered Encoder
. For example:
-
Java
-
Kotlin
String securityToken = ... ;
ViewBox viewBox = ... ;
MimeType mimeType = MimeType.valueOf("message/x.rsocket.authentication.bearer.v0");
Flux<AirportLocation> locations = requester.route("locate.radars.within")
.metadata(securityToken, mimeType)
.data(viewBox)
.retrieveFlux(AirportLocation.class);
import org.springframework.messaging.rsocket.retrieveFlow
val requester: RSocketRequester = ...
val securityToken: String = ...
val viewBox: ViewBox = ...
val mimeType = MimeType.valueOf("message/x.rsocket.authentication.bearer.v0")
val locations = requester.route("locate.radars.within")
.metadata(securityToken, mimeType)
.data(viewBox)
.retrieveFlow<AirportLocation>()
For Fire-and-Forget
use the send()
method that returns Mono<Void>
. Note that the Mono
indicates only that the message was successfully sent, and not that it was handled.
For Metadata-Push
use the sendMetadata()
method with a Mono<Void>
return value.
Annotated Responders
RSocket responders can be implemented as @MessageMapping
and @ConnectMapping
methods.
@MessageMapping
methods handle individual requests while @ConnectMapping
methods handle
connection-level events (setup and metadata push). Annotated responders are supported
symmetrically, for responding from the server side and for responding from the client side.
Server Responders
To use annotated responders on the server side, add RSocketMessageHandler
to your Spring
configuration to detect @Controller
beans with @MessageMapping
and @ConnectMapping
methods:
-
Java
-
Kotlin
@Configuration
static class ServerConfig {
@Bean
public RSocketMessageHandler rsocketMessageHandler() {
RSocketMessageHandler handler = new RSocketMessageHandler();
handler.routeMatcher(new PathPatternRouteMatcher());
return handler;
}
}
@Configuration
class ServerConfig {
@Bean
fun rsocketMessageHandler() = RSocketMessageHandler().apply {
routeMatcher = PathPatternRouteMatcher()
}
}
Then start an RSocket server through the Java RSocket API and plug the
RSocketMessageHandler
for the responder as follows:
-
Java
-
Kotlin
ApplicationContext context = ... ;
RSocketMessageHandler handler = context.getBean(RSocketMessageHandler.class);
CloseableChannel server =
RSocketServer.create(handler.responder())
.bind(TcpServerTransport.create("localhost", 7000))
.block();
import org.springframework.beans.factory.getBean
val context: ApplicationContext = ...
val handler = context.getBean<RSocketMessageHandler>()
val server = RSocketServer.create(handler.responder())
.bind(TcpServerTransport.create("localhost", 7000))
.awaitSingle()
RSocketMessageHandler
supports
composite and
routing metadata by default. You can set its
MetadataExtractor if you need to switch to a
different mime type or register additional metadata mime types.
You’ll need to set the Encoder
and Decoder
instances required for metadata and data
formats to support. You’ll likely need the spring-web
module for codec implementations.
By default SimpleRouteMatcher
is used for matching routes via AntPathMatcher
.
We recommend plugging in the PathPatternRouteMatcher
from spring-web
for
efficient route matching. RSocket routes can be hierarchical but are not URL paths.
Both route matchers are configured to use "." as separator by default and there is no URL
decoding as with HTTP URLs.
RSocketMessageHandler
can be configured via RSocketStrategies
which may be useful if
you need to share configuration between a client and a server in the same process:
-
Java
-
Kotlin
@Configuration
static class ServerConfig {
@Bean
public RSocketMessageHandler rsocketMessageHandler() {
RSocketMessageHandler handler = new RSocketMessageHandler();
handler.setRSocketStrategies(rsocketStrategies());
return handler;
}
@Bean
public RSocketStrategies rsocketStrategies() {
return RSocketStrategies.builder()
.encoders(encoders -> encoders.add(new Jackson2CborEncoder()))
.decoders(decoders -> decoders.add(new Jackson2CborDecoder()))
.routeMatcher(new PathPatternRouteMatcher())
.build();
}
}
@Configuration
class ServerConfig {
@Bean
fun rsocketMessageHandler() = RSocketMessageHandler().apply {
rSocketStrategies = rsocketStrategies()
}
@Bean
fun rsocketStrategies() = RSocketStrategies.builder()
.encoders { it.add(Jackson2CborEncoder()) }
.decoders { it.add(Jackson2CborDecoder()) }
.routeMatcher(PathPatternRouteMatcher())
.build()
}
Client Responders
Annotated responders on the client side need to be configured in the
RSocketRequester.Builder
. For details, see
Client Responders.
@MessageMapping
Once server or
client responder configuration is in place,
@MessageMapping
methods can be used as follows:
-
Java
-
Kotlin
@Controller
public class RadarsController {
@MessageMapping("locate.radars.within")
public Flux<AirportLocation> radars(MapRequest request) {
// ...
}
}
@Controller
class RadarsController {
@MessageMapping("locate.radars.within")
fun radars(request: MapRequest): Flow<AirportLocation> {
// ...
}
}
The above @MessageMapping
method responds to a Request-Stream interaction having the
route "locate.radars.within". It supports a flexible method signature with the option to
use the following method arguments:
Method Argument | Description |
---|---|
|
The payload of the request. This can be a concrete value of asynchronous types like
Note: Use of the annotation is optional. A method argument that is not a simple type and is not any of the other supported arguments, is assumed to be the expected payload. |
|
Requester for making requests to the remote end. |
|
Value extracted from the route based on variables in the mapping pattern, e.g.
|
|
Metadata value registered for extraction as described in MetadataExtractor. |
|
All metadata values registered for extraction as described in MetadataExtractor. |
The return value is expected to be one or more Objects to be serialized as response
payloads. That can be asynchronous types like Mono
or Flux
, a concrete value, or
either void
or a no-value asynchronous type such as Mono<Void>
.
The RSocket interaction type that an @MessageMapping
method supports is determined from
the cardinality of the input (i.e. @Payload
argument) and of the output, where
cardinality means the following:
Cardinality | Description |
---|---|
1 |
Either an explicit value, or a single-value asynchronous type such as |
Many |
A multi-value asynchronous type such as |
0 |
For input this means the method does not have an For output this is |
The table below shows all input and output cardinality combinations and the corresponding interaction type(s):
Input Cardinality | Output Cardinality | Interaction Types |
---|---|---|
0, 1 |
0 |
Fire-and-Forget, Request-Response |
0, 1 |
1 |
Request-Response |
0, 1 |
Many |
Request-Stream |
Many |
0, 1, Many |
Request-Channel |
@ConnectMapping
@ConnectMapping
handles the SETUP
frame at the start of an RSocket connection, and
any subsequent metadata push notifications through the METADATA_PUSH
frame, i.e.
metadataPush(Payload)
in io.rsocket.RSocket
.
@ConnectMapping
methods support the same arguments as
@MessageMapping but based on metadata and data from the SETUP
and
METADATA_PUSH
frames. @ConnectMapping
can have a pattern to narrow handling to
specific connections that have a route in the metadata, or if no patterns are declared
then all connections match.
@ConnectMapping
methods cannot return data and must be declared with void
or
Mono<Void>
as the return value. If handling returns an error for a new
connection then the connection is rejected. Handling must not be held up to make
requests to the RSocketRequester
for the connection. See
Server Requester for details.
MetadataExtractor
Responders must interpret metadata. Composite metadata allows independently formatted metadata values (e.g. for routing, security, tracing) each with its own mime type. Applications need a way to configure metadata mime types to support, and a way to access extracted values.
MetadataExtractor
is a contract to take serialized metadata and return decoded
name-value pairs that can then be accessed like headers by name, for example via @Header
in annotated handler methods.
DefaultMetadataExtractor
can be given Decoder
instances to decode metadata. Out of
the box it has built-in support for
"message/x.rsocket.routing.v0" which it decodes to
String
and saves under the "route" key. For any other mime type you’ll need to provide
a Decoder
and register the mime type as follows:
-
Java
-
Kotlin
DefaultMetadataExtractor extractor = new DefaultMetadataExtractor(metadataDecoders);
extractor.metadataToExtract(fooMimeType, Foo.class, "foo");
import org.springframework.messaging.rsocket.metadataToExtract
val extractor = DefaultMetadataExtractor(metadataDecoders)
extractor.metadataToExtract<Foo>(fooMimeType, "foo")
Composite metadata works well to combine independent metadata values. However the
requester might not support composite metadata, or may choose not to use it. For this,
DefaultMetadataExtractor
may needs custom logic to map the decoded value to the output
map. Here is an example where JSON is used for metadata:
-
Java
-
Kotlin
DefaultMetadataExtractor extractor = new DefaultMetadataExtractor(metadataDecoders);
extractor.metadataToExtract(
MimeType.valueOf("application/vnd.myapp.metadata+json"),
new ParameterizedTypeReference<Map<String,String>>() {},
(jsonMap, outputMap) -> {
outputMap.putAll(jsonMap);
});
import org.springframework.messaging.rsocket.metadataToExtract
val extractor = DefaultMetadataExtractor(metadataDecoders)
extractor.metadataToExtract<Map<String, String>>(MimeType.valueOf("application/vnd.myapp.metadata+json")) { jsonMap, outputMap ->
outputMap.putAll(jsonMap)
}
When configuring MetadataExtractor
through RSocketStrategies
, you can let
RSocketStrategies.Builder
create the extractor with the configured decoders, and
simply use a callback to customize registrations as follows:
-
Java
-
Kotlin
RSocketStrategies strategies = RSocketStrategies.builder()
.metadataExtractorRegistry(registry -> {
registry.metadataToExtract(fooMimeType, Foo.class, "foo");
// ...
})
.build();
import org.springframework.messaging.rsocket.metadataToExtract
val strategies = RSocketStrategies.builder()
.metadataExtractorRegistry { registry: MetadataExtractorRegistry ->
registry.metadataToExtract<Foo>(fooMimeType, "foo")
// ...
}
.build()
RSocket Interface
The Spring Framework lets you define an RSocket service as a Java interface with annotated methods for RSocket exchanges. You can then generate a proxy that implements this interface and performs the exchanges. This helps to simplify RSocket remote access by wrapping the use of the underlying RSocketRequester.
One, declare an interface with @RSocketExchange
methods:
interface RadarService {
@RSocketExchange("radars")
Flux<AirportLocation> getRadars(@Payload MapRequest request);
// more RSocket exchange methods...
}
Two, create a proxy that will perform the declared RSocket exchanges:
RSocketRequester requester = ... ;
RSocketServiceProxyFactory factory = RSocketServiceProxyFactory.builder(requester).build();
RadarService service = factory.createClient(RadarService.class);
Method Parameters
Annotated, RSocket exchange methods support flexible method signatures with the following method parameters:
Method argument | Description |
---|---|
|
Add a route variable to pass to |
|
Set the input payload(s) for the request. This can be a concrete value, or any producer
of values that can be adapted to a Reactive Streams |
|
The value for a metadata entry in the input payload. This can be any |
|
The |