Error running Spring Integration RSocket sample with Spring Boot

Question

I tried to create a simple Spring Boot applicaiton to test Spring Integrtaion for Rsocket.

I copied the sample codes in the test folder from spring-integrarion-rsocket to my Spring Boot application.

pom.xml

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-rsocket</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-integration</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.integration</groupId>
            <artifactId>spring-integration-rsocket</artifactId>
        </dependency>

And application.properties:

spring.rsocket.server.transport=tcp
server.port=7000

The main application class.

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}

@Configuration
class DemoIntegrationConfig {

    @Bean
    public ServerRSocketConnector serverRSocketConnector() {
        return new ServerRSocketConnector("localhost", 0);
    }

    @Bean
    public ClientRSocketConnector clientRSocketConnector(ServerRSocketConnector serverRSocketConnector) {
        int port = serverRSocketConnector.getBoundPort().block();
        ClientRSocketConnector clientRSocketConnector = new ClientRSocketConnector("localhost", port);
        clientRSocketConnector.setAutoStartup(false);
        return clientRSocketConnector;
    }

    @Bean
    public IntegrationFlow rsocketUpperCaseRequestFlow(ClientRSocketConnector clientRSocketConnector) {
        return IntegrationFlows
                .from(Function.class)
                .handle(RSockets.outboundGateway("/uppercase")
                        .command((message) -> RSocketOutboundGateway.Command.requestStreamOrChannel)
                        .expectedResponseType("T(java.lang.String)")
                        .clientRSocketConnector(clientRSocketConnector))
                .get();
    }

    @Bean
    public IntegrationFlow rsocketUpperCaseFlow() {
        return IntegrationFlows
                .from(RSockets.inboundGateway("/uppercase"))
                .<Flux<String>, Flux<String>>transform((flux) -> flux.map(String::toUpperCase))
                .get();
    }

}

And the test codes.

@SpringBootTest
class DemoApplicationTests {

    @Autowired
    @Qualifier("rsocketUpperCaseRequestFlow.gateway")
    private Function<Flux<String>, Flux<String>> rsocketUpperCaseFlowFunction;

    @Test
    void testRsocketUpperCaseFlows() {
        Flux<String> result = this.rsocketUpperCaseFlowFunction.apply(Flux.just("a\n", "b\n", "c\n"));

        StepVerifier.create(result)
                .expectNext("A", "B", "C")
                .verifyComplete();
    }
}

When I ran the test, it threw exceptions: No handler for destination '/uppercase'.

2019-10-30 12:59:28.617  INFO 2800 --- [           main] com.example.demo.DemoApplicationTests    : Started DemoApplicationTests in 4.778 seconds (JVM running for 6.408)
org.springframework.messaging.MessageDeliveryException: No handler for destination '/uppercase'
        at org.springframework.messaging.rsocket.annotation.support.RSocketMessageHandler.handleNoMatch(RSocketMessageHandler.java:309)
        at org.springframework.messaging.handler.invocation.reactive.AbstractMethodMessageHandler.getHandlerMethod(AbstractMethodMessageHandler.java:445)
        at org.springframework.messaging.handler.invocation.reactive.AbstractMethodMessageHandler.handleMessage(AbstractMethodMessageHandler.java:417)
        at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.lambda$handleAndReply$4(MessagingRSocket.java:173)
        at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:44)
        at reactor.core.publisher.Mono.subscribe(Mono.java:4087)
        at reactor.core.publisher.FluxConcatArray$ConcatArraySubscriber.onComplete(FluxConcatArray.java:207)
        at reactor.core.publisher.FluxConcatArray.subscribe(FluxConcatArray.java:80)
        at reactor.core.publisher.Flux.subscribe(Flux.java:8134)
        at reactor.core.publisher.FluxSwitchOnFirst$AbstractSwitchOnFirstInner.onNext(FluxSwitchOnFirst.java:180)
        at reactor.core.publisher.FluxDoFinally$DoFinallySubscriber.onNext(FluxDoFinally.java:123)
        at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:203)
        at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:203)
        at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:203)
        at reactor.core.publisher.UnicastProcessor.drainRegular(UnicastProcessor.java:240)
        at reactor.core.publisher.UnicastProcessor.drain(UnicastProcessor.java:312)
        at reactor.core.publisher.UnicastProcessor.subscribe(UnicastProcessor.java:427)
        at reactor.core.publisher.Flux.subscribe(Flux.java:8134)
        at io.rsocket.internal.RateLimitableRequestPublisher.subscribe(RateLimitableRequestPublisher.java:74)
        at io.rsocket.RSocketResponder.handleStream(RSocketResponder.java:446)
        at io.rsocket.RSocketResponder.handleChannel(RSocketResponder.java:502)
        at io.rsocket.RSocketResponder.handleFrame(RSocketResponder.java:315)
        at reactor.core.publisher.LambdaSubscriber.onNext(LambdaSubscriber.java:160)
        at reactor.core.publisher.MonoFlatMapMany$FlatMapManyInner.onNext(MonoFlatMapMany.java:242)
        at reactor.core.publisher.FluxGroupBy$UnicastGroupedFlux.drainRegular(FluxGroupBy.java:554)
        at reactor.core.publisher.FluxGroupBy$UnicastGroupedFlux.drain(FluxGroupBy.java:630)
        at reactor.core.publisher.FluxGroupBy$UnicastGroupedFlux.subscribe(FluxGroupBy.java:696)
        at reactor.core.publisher.Flux.subscribe(Flux.java:8134)
        at reactor.core.publisher.MonoFlatMapMany$FlatMapManyMain.onNext(MonoFlatMapMany.java:188)
        at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1592)
        at reactor.core.publisher.MonoProcessor.onNext(MonoProcessor.java:317)
        at io.rsocket.internal.ClientServerInputMultiplexer.lambda$new$1(ClientServerInputMultiplexer.java:116)
        at reactor.core.publisher.LambdaSubscriber.onNext(LambdaSubscriber.java:160)
        at reactor.core.publisher.FluxGroupBy$GroupByMain.drainLoop(FluxGroupBy.java:380)
        at reactor.core.publisher.FluxGroupBy$GroupByMain.drain(FluxGroupBy.java:316)
        at reactor.core.publisher.FluxGroupBy$GroupByMain.onNext(FluxGroupBy.java:201)
        at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114)
        at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114)
        at reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:206)
        at reactor.netty.channel.FluxReceive.onInboundNext(FluxReceive.java:329)
        at reactor.netty.channel.ChannelOperations.onInboundNext(ChannelOperations.java:348)
        at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:91)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
        at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:328)
        at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:302)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352)
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1422)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360)
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:931)
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:700)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:635)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:552)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:514)
        at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1044)
        at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
        at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
        at java.base/java.lang.Thread.run(Thread.java:834)
[ERROR] Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 6.961 s <<< FAILURE! - in com.example.demo.DemoApplicationTests
[ERROR] testRsocketUpperCaseFlows  Time elapsed: 0.894 s  <<< FAILURE!

The source code is hosted on my Github.

BTW. I have to run this application as an embedded RSocket web flux application(or run it as a standalone RSocket application), if I run the RSocket server with the same port configured in the IntegrationConfig, there is a port binding error when I started the application, it seems ServerRSocketConnector will create its own RSocket Server.

Update:2/27/2020:

I tried to remove spring-boot-starter-rsocket in the dependencies and created a RestController to communicate with the gateway.

The update dependencies of pom.xml.

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-integration</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.integration</groupId>
            <artifactId>spring-integration-rsocket</artifactId>
        </dependency>

And clean the config in application.properties.

The sample RestController.

@RestController
class HelloController {

    @Autowired()
    @Lazy
    @Qualifier("rsocketUpperCaseRequestFlow.gateway")
    private Function<Flux<String>, Flux<String>> rsocketUpperCaseFlowFunction;

    @GetMapping(value = "hello", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
    public Flux<String> uppercase() {
        return rsocketUpperCaseFlowFunction.apply(Flux.just("a", "b", "c", "d"));
    }
}

When I ran the application, I got exceptions like this.

org.springframework.messaging.MessageDeliveryException: Destination '/uppercase' does not support REQUEST_CHANNEL. Supported interaction(s): [SETUP, METADATA_PUSH]
    at org.springframework.messaging.rsocket.annotation.support.RSocketMessageHandler.handleNoMatch(RSocketMessageHandler.java:389)
    at org.springframework.messaging.handler.invocation.reactive.AbstractMethodMessageHandler.getHandlerMethod(AbstractMethodMessageHandler.java:476)
    at org.springframework.messaging.handler.invocation.reactive.AbstractMethodMessageHandler.handleMessage(AbstractMethodMessageHandler.java:444)
    at org.springframework.messaging.rsocket.annotation.support.MessagingRSocket.lambda$handleAndReply$4(MessagingRSocket.java:173)
    at reactor.core.publisher.MonoDefer.subscribe(MonoDefer.java:44)
    at reactor.core.publisher.Mono.subscribe(Mono.java:4105)
    at reactor.core.publisher.FluxConcatArray$ConcatArraySubscriber.onComplete(FluxConcatArray.java:207)
    at reactor.core.publisher.FluxConcatArray.subscribe(FluxConcatArray.java:80)
    at reactor.core.publisher.Flux.subscribe(Flux.java:8174)
    at reactor.core.publisher.FluxSwitchOnFirst$AbstractSwitchOnFirstInner.onNext(FluxSwitchOnFirst.java:180)
    at reactor.core.publisher.FluxDoFinally$DoFinallySubscriber.onNext(FluxDoFinally.java:123)
    at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:203)
    at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:203)
    at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onNext(FluxPeekFuseable.java:203)
    at reactor.core.publisher.UnicastProcessor.drainRegular(UnicastProcessor.java:240)
    at reactor.core.publisher.UnicastProcessor.drain(UnicastProcessor.java:312)
    at reactor.core.publisher.UnicastProcessor.subscribe(UnicastProcessor.java:427)
    at reactor.core.publisher.Flux.subscribe(Flux.java:8174)
    at io.rsocket.internal.RateLimitableRequestPublisher.subscribe(RateLimitableRequestPublisher.java:74)
    at io.rsocket.RSocketResponder.handleStream(RSocketResponder.java:446)
    at io.rsocket.RSocketResponder.handleChannel(RSocketResponder.java:502)
    at io.rsocket.RSocketResponder.handleFrame(RSocketResponder.java:315)
    at reactor.core.publisher.LambdaSubscriber.onNext(LambdaSubscriber.java:160)
    at reactor.core.publisher.MonoFlatMapMany$FlatMapManyInner.onNext(MonoFlatMapMany.java:242)
    at reactor.core.publisher.FluxGroupBy$UnicastGroupedFlux.drainRegular(FluxGroupBy.java:554)
    at reactor.core.publisher.FluxGroupBy$UnicastGroupedFlux.drain(FluxGroupBy.java:630)
    at reactor.core.publisher.FluxGroupBy$UnicastGroupedFlux.subscribe(FluxGroupBy.java:696)
    at reactor.core.publisher.Flux.subscribe(Flux.java:8174)
    at reactor.core.publisher.MonoFlatMapMany$FlatMapManyMain.onNext(MonoFlatMapMany.java:188)
    at reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1637)
    at reactor.core.publisher.MonoProcessor.onNext(MonoProcessor.java:317)
    at io.rsocket.internal.ClientServerInputMultiplexer.lambda$new$1(ClientServerInputMultiplexer.java:116)
    at reactor.core.publisher.LambdaSubscriber.onNext(LambdaSubscriber.java:160)
    at reactor.core.publisher.FluxGroupBy$GroupByMain.drainLoop(FluxGroupBy.java:380)
    at reactor.core.publisher.FluxGroupBy$GroupByMain.drain(FluxGroupBy.java:316)
    at reactor.core.publisher.FluxGroupBy$GroupByMain.onNext(FluxGroupBy.java:201)
    at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114)
    at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114)
    at reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:218)
    at reactor.netty.channel.FluxReceive.onInboundNext(FluxReceive.java:351)
    at reactor.netty.channel.ChannelOperations.onInboundNext(ChannelOperations.java:348)
    at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:90)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355)
    at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:321)
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:295)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
    at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:714)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
    at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
    at java.base/java.lang.Thread.run(Thread.java:834)


java.lang.AssertionError: expectation "expectNext(A)" failed (expected: onNext(A); actual: onError(io.rsocket.exceptions.ApplicationErrorException: Destination '/uppercase' does not support REQUEST_CHANNEL. Supported interaction(s): [SETUP, METADATA_PUSH]))

    at reactor.test.MessageFormatter.assertionError(MessageFormatter.java:115)
    at reactor.test.MessageFormatter.failPrefix(MessageFormatter.java:104)
    at reactor.test.MessageFormatter.fail(MessageFormatter.java:73)
    at reactor.test.MessageFormatter.failOptional(MessageFormatter.java:88)
    at reactor.test.DefaultStepVerifierBuilder.lambda$addExpectedValue$10(DefaultStepVerifierBuilder.java:501)
    at reactor.test.DefaultStepVerifierBuilder$SignalEvent.test(DefaultStepVerifierBuilder.java:2211)
    at reactor.test.DefaultStepVerifierBuilder$DefaultVerifySubscriber.onSignal(DefaultStepVerifierBuilder.java:1483)
    at reactor.test.DefaultStepVerifierBuilder$DefaultVerifySubscriber.onExpectation(DefaultStepVerifierBuilder.java:1431)
    at reactor.test.DefaultStepVerifierBuilder$DefaultVerifySubscriber.onError(DefaultStepVerifierBuilder.java:1091)
    at reactor.core.publisher.FluxMap$MapSubscriber.onError(FluxMap.java:126)
    at reactor.core.publisher.FluxMap$MapSubscriber.onError(FluxMap.java:126)
    at reactor.core.publisher.FluxDoFinally$DoFinallySubscriber.onError(FluxDoFinally.java:129)
    at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onError(FluxPeekFuseable.java:227)
    at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onError(FluxPeekFuseable.java:227)
    at reactor.core.publisher.FluxPeekFuseable$PeekFuseableSubscriber.onError(FluxPeekFuseable.java:227)
    at reactor.core.publisher.UnicastProcessor.checkTerminated(UnicastProcessor.java:334)
    at reactor.core.publisher.UnicastProcessor.drainRegular(UnicastProcessor.java:232)
    at reactor.core.publisher.UnicastProcessor.drain(UnicastProcessor.java:312)
    at reactor.core.publisher.UnicastProcessor.onError(UnicastProcessor.java:401)
    at io.rsocket.RSocketRequester.handleFrame(RSocketRequester.java:556)
    at io.rsocket.RSocketRequester.handleIncomingFrames(RSocketRequester.java:516)
    at reactor.core.publisher.LambdaSubscriber.onNext(LambdaSubscriber.java:160)
    at reactor.core.publisher.MonoFlatMapMany$FlatMapManyInner.onNext(MonoFlatMapMany.java:242)
    at reactor.core.publisher.FluxGroupBy$UnicastGroupedFlux.drainRegular(FluxGroupBy.java:554)
    at reactor.core.publisher.FluxGroupBy$UnicastGroupedFlux.drain(FluxGroupBy.java:630)
    at reactor.core.publisher.FluxGroupBy$UnicastGroupedFlux.onNext(FluxGroupBy.java:670)
    at reactor.core.publisher.FluxGroupBy$GroupByMain.onNext(FluxGroupBy.java:205)
    at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114)
    at reactor.core.publisher.FluxMap$MapSubscriber.onNext(FluxMap.java:114)
    at reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:218)
    at reactor.netty.channel.FluxReceive.onInboundNext(FluxReceive.java:351)
    at reactor.netty.channel.ChannelOperations.onInboundNext(ChannelOperations.java:348)
    at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:90)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355)
    at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:321)
    at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:308)
    at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:422)
    at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)
    at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:355)
    at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:377)
    at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:363)
    at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
    at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:714)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650)
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576)
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
    at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
    at java.base/java.lang.Thread.run(Thread.java:834)
    Suppressed: io.rsocket.exceptions.ApplicationErrorException: Destination '/uppercase' does not support REQUEST_CHANNEL. Supported interaction(s): [SETUP, METADATA_PUSH]
        at io.rsocket.exceptions.Exceptions.from(Exceptions.java:45)
        ... 37 more

Answer 1

I have just made a new project from https://start.spring.io with all your code and it works well for me. I use Spring Boot 2.2.0.

Although I see that there is no correlation between RSocket auto-configuration and what we have with the ServerRSocketConnector.

We need somehow make ServerRSocketConnector based on whatever we have auto-configure in Spring Boot for RSocket support. Feel free to raise an issue on the matter in Spring Boot! then we will try to figure out what and how has to be implemented over there and/or in Spring Integration.