RSocketClient and RSocketConnector Javadoc update (#856)

Signed-off-by: Rossen Stoyanchev <[email protected]>
(cherry picked from commit 07cf959)

Author: rstoyanchev

rsocket-core/src/main/java/io/rsocket/RSocketClient.java

@@ -4,69 +4,79 @@
 import reactor.core.Disposable;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
+import reactor.util.retry.Retry;
 
 /**
- * A client-side interface to simplify interactions with the {@link
- * io.rsocket.core.RSocketConnector}. This interface represents logical communication over {@link
- * RSocket}, hiding the complexity of {@code Mono<RSocket>} resolution. Also, in opposite to {@link
- * RSocket} , {@link RSocketClient} supports multi-subscription on the same {@link Publisher} from
- * the interaction in the way of accepting input as {@link Publisher} like {@link Mono} or {@link
- * Flux} Despite, {@link RSocket} interface, {@link RSocketClient} does not coupled with a single
- * connection, hence disposal of the {@link #source()} {@link RSocket} will affect the {@link
- * RSocketClient} it selves. In such a case, a new request will cause automatic reconnection if
- * necessary.
+ * Contract to perform RSocket requests from client to server, transparently connecting and ensuring
+ * a single, shared connection to make requests with.
+ *
+ * <p>{@code RSocketClient} contains a {@code Mono<RSocket>} {@link #source() source}. It uses it to
+ * obtain a live, shared {@link RSocket} connection on the first request and on subsequent requests
+ * if the connection is lost. This eliminates the need to obtain a connection first, and makes it
+ * easy to pass a single {@code RSocketClient} to use from multiple places.
+ *
+ * <p>Request methods of {@code RSocketClient} allow multiple subscriptions with each subscription
+ * performing a new request. Therefore request methods accept {@code Mono<Payload>} rather than
+ * {@code Payload} as on {@link RSocket}. By contrast, {@link RSocket} request methods cannot be
+ * subscribed to more than once.
+ *
+ * <p>Use {@link io.rsocket.core.RSocketConnector RSocketConnector} to create a client:
+ *
+ * <pre class="code">{@code
+ * RSocketClient client =
+ *         RSocketConnector.create()
+ *                 .metadataMimeType("message/x.rsocket.composite-metadata.v0")
+ *                 .dataMimeType("application/cbor")
+ *                 .toRSocketClient(TcpClientTransport.create("localhost", 7000));
+ * }</pre>
+ *
+ * <p>Use the {@link io.rsocket.core.RSocketConnector#reconnect(Retry) RSocketConnector#reconnect}
+ * method to configure the retry logic to use whenever a shared {@code RSocket} connection needs to
+ * be obtained:
+ *
+ * <pre class="code">{@code
+ * RSocketClient client =
+ *         RSocketConnector.create()
+ *                 .metadataMimeType("message/x.rsocket.composite-metadata.v0")
+ *                 .dataMimeType("application/cbor")
+ *                 .reconnect(Retry.fixedDelay(3, Duration.ofSeconds(1)))
+ *                 .toRSocketClient(TcpClientTransport.create("localhost", 7000));
+ * }</pre>
  *
  * @since 1.0.1
  */
 public interface RSocketClient extends Disposable {
 
-  /**
-   * Provides access to the source {@link RSocket} used by this {@link RSocketClient}
-   *
-   * @return returns a {@link Mono} which returns the source {@link RSocket}
-   */
+  /** Return the underlying source used to obtain a shared {@link RSocket} connection. */
   Mono<RSocket> source();
 
   /**
-   * Fire and Forget interaction model of {@link RSocketClient}.
-   *
-   * @param payloadMono Request payload as {@link Mono}.
-   * @return {@code Publisher} that completes when the passed {@code payload} is successfully
-   *     handled, otherwise errors.
+   * Perform a Fire-and-Forget interaction via {@link RSocket#fireAndForget(Payload)}. Allows
+   * multiple subscriptions and performs a request per subscriber.
    */
   Mono<Void> fireAndForget(Mono<Payload> payloadMono);
 
   /**
-   * Request-Response interaction model of {@link RSocketClient}.
-   *
-   * @param payloadMono Request payload as {@link Mono}.
-   * @return {@code Publisher} containing at most a single {@code Payload} representing the
-   *     response.
+   * Perform a Request-Response interaction via {@link RSocket#requestResponse(Payload)}. Allows
+   * multiple subscriptions and performs a request per subscriber.
    */
   Mono<Payload> requestResponse(Mono<Payload> payloadMono);
 
   /**
-   * Request-Stream interaction model of {@link RSocketClient}.
-   *
-   * @param payloadMono Request payload as {@link Mono}.
-   * @return {@code Publisher} containing the stream of {@code Payload}s representing the response.
+   * Perform a Request-Stream interaction via {@link RSocket#requestStream(Payload)}. Allows
+   * multiple subscriptions and performs a request per subscriber.
    */
   Flux<Payload> requestStream(Mono<Payload> payloadMono);
 
   /**
-   * Request-Channel interaction model of {@link RSocketClient}.
-   *
-   * @param payloads Stream of request payloads.
-   * @return Stream of response payloads.
+   * Perform a Request-Channel interaction via {@link RSocket#requestChannel(Publisher)}. Allows
+   * multiple subscriptions and performs a request per subscriber.
    */
   Flux<Payload> requestChannel(Publisher<Payload> payloads);
 
   /**
-   * Metadata-Push interaction model of {@link RSocketClient}.
-   *
-   * @param payloadMono Request payload as {@link Mono}.
-   * @return {@code Publisher} that completes when the passed {@code payload} is successfully
-   *     handled, otherwise errors.
+   * Perform a Metadata Push via {@link RSocket#metadataPush(Payload)}. Allows multiple
+   * subscriptions and performs a request per subscriber.
    */
   Mono<Void> metadataPush(Mono<Payload> payloadMono);
 }

rsocket-core/src/main/java/io/rsocket/core/RSocketConnector.java

@@ -53,23 +53,23 @@
 /**
  * The main class to use to establish a connection to an RSocket server.
  *
- * <p>To connect over TCP using default settings:
+ * <p>For using TCP using default settings:
  *
  * <pre>{@code
  * import io.rsocket.transport.netty.client.TcpClientTransport;
  *
- * Mono<RSocket> rocketMono =
- *         RSocketConnector.connectWith(TcpClientTransport.create("localhost", 7000));
+ * RSocketClient client =
+ *         RSocketConnector.createRSocketClient(TcpClientTransport.create("localhost", 7000));
  * }</pre>
  *
  * <p>To customize connection settings before connecting:
  *
  * <pre>{@code
- * Mono<RSocket> rocketMono =
+ * RSocketClient client =
  *         RSocketConnector.create()
  *                 .metadataMimeType("message/x.rsocket.composite-metadata.v0")
  *                 .dataMimeType("application/cbor")
- *                 .connect(TcpClientTransport.create("localhost", 7000));
+ *                 .toRSocketClient(TcpClientTransport.create("localhost", 7000));
  * }</pre>
  */
 public class RSocketConnector {
@@ -448,11 +448,42 @@ public RSocketConnector payloadDecoder(PayloadDecoder decoder) {
   }
 
   /**
-   * The final step to connect with the transport to use as input and the resulting {@code
-   * Mono<RSocket>} as output. Each subscriber to the returned {@code Mono} starts a new connection
-   * if neither {@link #reconnect(Retry) reconnect} nor {@link #resume(Resume)} are enabled.
+   * Create {@link RSocketClient} that will use {@link #connect(ClientTransport)} as its source to
+   * obtain a live, shared {@code RSocket} when the first request is made, and also on subsequent
+   * requests after the connection is lost.
    *
-   * <p>The following transports are available (via additional RSocket Java modules):
+   * <p>The following transports are available through additional RSocket Java modules:
+   *
+   * <ul>
+   *   <li>{@link io.rsocket.transport.netty.client.TcpClientTransport TcpClientTransport} via
+   *       {@code rsocket-transport-netty}.
+   *   <li>{@link io.rsocket.transport.netty.client.WebsocketClientTransport
+   *       WebsocketClientTransport} via {@code rsocket-transport-netty}.
+   *   <li>{@link io.rsocket.transport.local.LocalClientTransport LocalClientTransport} via {@code
+   *       rsocket-transport-local}
+   * </ul>
+   *
+   * @param transport the transport of choice to connect with
+   * @return a {@code RSocketClient} with not established connection. Note, connection will be
+   *     established on the first request
+   * @since 1.0.1
+   */
+  public RSocketClient toRSocketClient(ClientTransport transport) {
+    Mono<RSocket> source = connect0(() -> transport);
+
+    if (retrySpec != null) {
+      source = source.retryWhen(retrySpec);
+    }
+
+    return new DefaultRSocketClient(source);
+  }
+
+  /**
+   * Connect with the given transport and obtain a live {@link RSocket} to use for making requests.
+   * Each subscriber to the returned {@code Mono} receives a new connection, if neither {@link
+   * #reconnect(Retry) reconnect} nor {@link #resume(Resume)} are enabled.
+   *
+   * <p>The following transports are available through additional RSocket Java modules:
    *
    * <ul>
    *   <li>{@link io.rsocket.transport.netty.client.TcpClientTransport TcpClientTransport} via
@@ -492,40 +523,6 @@ public Mono<RSocket> connect(Supplier<ClientTransport> transportSupplier) {
             });
   }
 
-  /**
-   * The final step to connect with the transport to use as input and the resulting {@link
-   * RSocketClient} as output.
-   *
-   * <p>Please note, {@link RSocketClient} does not represent a single or wired connection and will
-   * do that depends on the demand (pending requests). Therefore, in order to ensure that connection
-   * will be established in a case of error, {@link #reconnect(Retry) reconnect} may be enabled.
-   *
-   * <p>The following transports are available (via additional RSocket Java modules):
-   *
-   * <ul>
-   *   <li>{@link io.rsocket.transport.netty.client.TcpClientTransport TcpClientTransport} via
-   *       {@code rsocket-transport-netty}.
-   *   <li>{@link io.rsocket.transport.netty.client.WebsocketClientTransport
-   *       WebsocketClientTransport} via {@code rsocket-transport-netty}.
-   *   <li>{@link io.rsocket.transport.local.LocalClientTransport LocalClientTransport} via {@code
-   *       rsocket-transport-local}
-   * </ul>
-   *
-   * @param transport the transport of choice to connect with
-   * @return a {@code RSocketClient} with not established connection. Note, connection will be
-   *     established on the first request
-   * @since 1.0.1
-   */
-  public RSocketClient toRSocketClient(ClientTransport transport) {
-    Mono<RSocket> source = connect0(() -> transport);
-
-    if (retrySpec != null) {
-      source = source.retryWhen(retrySpec);
-    }
-
-    return new DefaultRSocketClient(source);
-  }
-
   private Mono<RSocket> connect0(Supplier<ClientTransport> transportSupplier) {
     Mono<DuplexConnection> connectionMono =
         Mono.fromSupplier(transportSupplier)