Spring Integration HTTP Outbound Gateway Post Request with Java DSL

Question

I am trying to consume a rest service and receive a json back and convert it to a list of objects. but I am receiving the below erorr. I am new to EIP and there aren't many tutorials for doing this in java dsl. I have configured 2 channels, one for sending a request and one for receiving the payload back.

Exception in thread "main" org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'httpPostAtms' is expected to be of type 'org.springframework.messaging.MessageChannel' but was actually of type 'org.springframework.integration.dsl.StandardIntegrationFlow'
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:378)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.integration.support.channel.BeanFactoryChannelResolver.resolveDestination(BeanFactoryChannelResolver.java:89)
at org.springframework.integration.support.channel.BeanFactoryChannelResolver.resolveDestination(BeanFactoryChannelResolver.java:46)
at org.springframework.integration.gateway.MessagingGatewaySupport.getRequestChannel(MessagingGatewaySupport.java:344)
at org.springframework.integration.gateway.MessagingGatewaySupport.doSendAndReceive(MessagingGatewaySupport.java:433)
at org.springframework.integration.gateway.MessagingGatewaySupport.sendAndReceive(MessagingGatewaySupport.java:422)
at org.springframework.integration.gateway.GatewayProxyFactoryBean.invokeGatewayMethod(GatewayProxyFactoryBean.java:474)
at org.springframework.integration.gateway.GatewayProxyFactoryBean.doInvoke(GatewayProxyFactoryBean.java:429)
at org.springframework.integration.gateway.GatewayProxyFactoryBean.invoke(GatewayProxyFactoryBean.java:420)
at org.springframework.integration.gateway.GatewayCompletableFutureProxyFactoryBean.invoke(GatewayCompletableFutureProxyFactoryBean.java:65)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)
at com.sun.proxy.$Proxy70.getAllAtms(Unknown Source)
at com.backbase.atm.IngAtmApplication.main(IngAtmApplication.java:25)

I am using SI with Spring Boot

@IntegrationComponentScan
@Configuration
@EnableIntegration
@ComponentScan
public class InfrastructorConfig {

    @Bean
    public PollableChannel requestChannel() {
        return new PriorityChannel() ;
    }

    @Bean
    public MessageChannel replyChannel() {
        return new DirectChannel() ;
    }

    @Bean(name = PollerMetadata.DEFAULT_POLLER)
    public PollerMetadata poller() {
        return Pollers.fixedRate(500).get();
    }

    @Bean
    public IntegrationFlow httpPostAtms() {

        return IntegrationFlows.from("requestChannel")
                .handle(Http.outboundGateway("https://www.ing.nl/api/locator/atms/")
                        .httpMethod(HttpMethod.POST)
                        .extractPayload(true))
                .<String, String>transform(p -> p.substring(5))
                .transform(Transformers.fromJson(Atm[].class))
                .channel("responseChannel")
                .get();

      }

    }

The Gateway

package com.backbase.atm.service;

import java.util.List;

import org.springframework.integration.annotation.Gateway;
import org.springframework.integration.annotation.MessagingGateway;
import org.springframework.messaging.handler.annotation.Payload;

import com.backbase.atm.model.Atm;

@MessagingGateway
public interface IntegrationService {

    @Gateway(requestChannel = "httpPostAtms")
    @Payload("new java.util.Date()")
    List<Atm> getAllAtms();
}

Application Start

package com.backbase.atm;

import java.util.ArrayList;
import java.util.List;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;
import com.backbase.atm.service.IntegrationService;


@SpringBootApplication
public class IngAtmApplication {


    public static void main(String[] args) {
        ConfigurableApplicationContext ctx = SpringApplication.run(IngAtmApplication.class, args);
        ctx.getBean(IntegrationService.class).getAllAtms();
        ctx.close();
    }

Answer 1

You have to use requestChannel bean name in the gateway definition. Right now you have there an IntegrationFlow bean name, but that is wrong.

Always remember that everything in Spring Integration are connected via channels.