Spring集成-入站通道适配器是多线程的吗？

Question

I have the following spring-integration configuration v1.0.4.

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:mail="http://www.springframework.org/schema/integration/mail"
xmlns:int="http://www.springframework.org/schema/integration"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
    http://www.springframework.org/schema/integration/mail
    http://www.springframework.org/schema/integration/mail/spring-integration-mail-2.1.xsd 
    http://www.springframework.org/schema/util 
    http://www.springframework.org/schema/util/spring-util-2.0.xsd">


    <util:properties id="javaMailProperties">
    <prop key="mail.imap.socketFactory.class">javax.net.ssl.SSLSocketFactory</prop>
    <prop key="mail.imap.socketFactory.fallback">false</prop>
    <prop key="mail.store.protocol">imaps</prop>
    <prop key="mail.debug">false</prop>
</util:properties>

 <mail:inbound-channel-adapter id="imapAdapter"
                                  store-uri="imaps://user:pass@domain:993/inbox"                                    
                                  channel="recieveEmailChannel"
                                  auto-startup="true"                                      
                                  java-mail-properties="javaMailProperties">
    <int:poller> 
    <int:interval-trigger initial-delay="1000" interval="2000"
    fixed-rate="true"/>
    </int:poller>
</mail:inbound-channel-adapter>

<int:channel id="recieveEmailChannel">        
    <int:interceptors>
        <int:wire-tap channel="logger"/>
    </int:interceptors>
</int:channel>

<int:logging-channel-adapter id="logger" level="DEBUG"/>

<int:service-activator input-channel="recieveEmailChannel" ref="emailReceiverService" method="receive"/>

<bean id="emailReceiverService" class="com.mycompany.DefaultEmailReceiverUtilService">
</bean>

DefaultEmailReceiverUtilService

public class DefaultEmailReceiverUtilService implements
        EmailReceiverUtilService
{

    public void receive(Message<?> message)
    {
        //Processing the emails
    }
}

Question:

1. Is it multithreaded? or the Emails will be processed in a serial fashion?. If yes then how to make it multithreaded?
2. When my application is running in eclipse debug mode, I can see some Timer task threads, but each request is going to same timer task in a sequential fashion, also my number of threads (Timer task) are steadily growing. I may be misinterpret it.

Please correct me if I am wrong.

Answer 1

What I think you need is a queue channel. Your receiveEmailChannel should be something like:

<int:channel id="recieveEmailChannel">  
<int:queue/>
<int:interceptors>
    <int:wire-tap channel="logger"/>
</int:interceptors>
</int:channel>

Which I'm sure you'll know is how you define a queue channel. The point to point channel which is what you have currently is synchronous it can only have 1 message passed at a time.

Currently if you'd add something to that channel it would wait until the service activator has finished whilst with a queue channel the service activator should fire off a new thread as soon as it detects something in the queue.