Http 出站网关正在工作但未拨打电话 - 使用 spring 集成 DSL java

Question

I am a newbie in the spring integration framework. Below is my code, I am actually trying to make some HTTP calls using HTTP outbound gateway using SI DSL configuration. When I ran the code the IntegrationFlow methods are called but the HTTP hit is not making. I am not sure why.

Main class

@EnableIntegration
@Configuration
@Import({ AptHttp.class })
public class DemosiApplication {

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

}

config class

@Configuration
@IntegrationComponentScan
public class AptHttp {

    @EnableIntegration
    public static class ContextConfiguration {

        @Bean("inputChannel")
        public MessageChannel inputChannel() {
            return MessageChannels.direct().get();
        }

        @Bean
        public MessageChannel outputChannel() {
            return MessageChannels.direct().get();
        }

        @Bean
        public IntegrationFlow outBoundFlow() {
            System.out.println("Inside t outBoundFlow flow ");
            final String uri = "http://localhost:9090/api/test";
            return f -> f.channel(inputChannel())
                    .handle(Http.outboundGateway(uri).httpMethod(HttpMethod.GET).expectedResponseType(String.class))
                    .channel(outputChannel());
        }

    }

}

Above two classes only. I don't get any error too when I ran the SI application (sysout are printing but the call is not made I don't know why ). I have another application where I can have some API through the spring integration code I am trying to hit that API method. To understand the flow of HTTP outbound gateway I am trying this way.

Could anyone please help/ suggest me on this.

Answer 1

You don't show (or don't have) the code which sends messages into the inputChannel .

The Http.outboundGateway() is not an active components and its work has to be triggered by the request message.

Also there are two main phases in Spring application context: bean creation and runtime. So, you see that System.out.println() during bean creation phase. It has nothing to do with runtime when really a send over HTTP happens.

So, after crating and starting an application context ( SpringApplication.run(DemosiApplication.class, args); ) you need to take an inputChannel bean and send a Message<?> into it. Only after that your HTTP Outbound Gateway is going to be triggered.

See more info in samples: https://github.com/spring-projects/spring-integration-samples

Answer 2

I am sharing my answer those who are looking for an example for HTTP outbound gateway using java DSL.

Main class

@SpringBootApplication(scanBasePackages="com.testsi")
@EnableIntegration
@IntegrationComponentScan
public class DemosiApplication {

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



        @Bean
        @Qualifier("get_send_channel")
        MessageChannel getSendChannel() {
            return MessageChannels.direct().get();
        }

        @Bean
        @Qualifier("get_receive_channel")
        PollableChannel getReceiveChannel() {
         return new PriorityChannel() ;
        }

        @Bean
        public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
            System.out.println("inside the command liner ");
            return args -> {
                Message<?> message = MessageBuilder.withPayload("").build();
                System.out.println("Message [ayload =>"+ message.getPayload());
                getSendChannel().send(message);
                System.out.println("we are getting an output from test application"+getReceiveChannel().receive().getPayload());
            };
        }

        @Bean
        public IntegrationFlow outBoundFlow() {
            System.out.println("Inside t outBoundFlow flow ");
            final String uri = "http://localhost:9090/api/test/1";
            return IntegrationFlows.from(getSendChannel())
                    .handle(Http.outboundGateway(uri).httpMethod(HttpMethod.POST).expectedResponseType(String.class))
                    .channel(getReceiveChannel()).get();
        }

        @Bean
        public IntegrationFlow outBoundFlow() {
            System.out.println("Inside t outBoundFlow flow ");
            final String uri = "http://localhost:9090/api/test";
            return IntegrationFlows.from(getSendChannel())
                    .handle(Http.outboundGateway(uri).httpMethod(HttpMethod.GET).expectedResponseType(String.class))
                    .channel(getReceiveChannel()).get();
        }
        }

Thanks @Artem Bilan.