如何配置Spring Integration？

Question

I have spring-integration-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/integration" //etc. >

<channel id="inputChannel"/>

<channel id="outputChannel">
    <queue capacity="10"/>
</channel>

<service-activator input-channel="inputChannel"
                   output-channel="outputChannel"
                   ref="gmailWorker"
                   method="getGmailMessage"/>

<beans:bean id="gmailWorker" class="GmailWorker"/>

Configuation:

@Configuration
@ImportResource("classpath:spring-integration-config.xml")
public class PropertiesConfig {
}

And GmailWorker:

public class GmailWorker{
public static Message getGmailMessage(Gmail service,String messageId) throws IOException {
    Message gmailMessage = service.users().messages().get("me", messageId).execute();
    return gmailMessage;
}
}

Now I don't use InputChannel bean. But my application doesn't deployed on tomcat with logs:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.integration.config.ConsumerEndpointFactoryBean#0': 
Cannot resolve reference to bean 'org.springframework.integration.config.ServiceActivatorFactoryBean#0' while setting bean property 'handler'; 
nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.integration.config.ServiceActivatorFactoryBean#0':
FactoryBean threw exception on object creation; nested exception is java.lang.IllegalArgumentException: 
Target object of type [class GmailWorker] has no eligible methods for handling Messages.

How to configure Spring Integration? And how use inputChannel in application?

Answer 1

Your POJO method looks bad for Spring Integration runtime method invocation engine.

Any Spring Integration component gets deal with Message object, which has headers and payload properties.

When it invokes the POJO method it expects some restricted set of arguments on the method:

• Whole Message
• any other type which may be treated as payload , if there is some appropriate converter on the matter.
• @Header as the request for some header in the MessageHeaders
• Map<String, Object> as whole set of MessageHeaders`
• If you want get deal with payload and some headers you can mark params with @Payload , @Headers etc..

More info is here .