Using JAVA NIO framework in SPRING server

I'm implementing an hybrid server application that mixes a Web-Servlet and a plain Java application.

The java application manages thousands of sockets for remote devices, while the Web application interacts with the user to set/read the state of any socket. Java NIO, or Apache-MINA vs Jboss-Netty, seems to be good options for the sockets application.

The first question is, can I run both applications (Servlet with web interface + JAVA NIO application) in the same server? I'am using now Tomcat for the Servlet and a plain procrun daemon for the socket-application

I don't know if Spring is suitable for this combination, since I haven't seen any information about using NIO in Spring.

The second question is, how can both applications communicate between them? For the moment I'am using RMI but I wonder if there is a better solution.

You can definitely run a NIO socket server and a web server in the same jvm using Spring. I have done it using Grails (which is a wrapper over spring anyway). I start the tcp server in the bootstrap class of Grails.

For normal spring web app, you can start the socket server listening at a particular port, say 8090 and the web server at say 8080 using spring framework lifecycle listeners or post processors.

Make your socket server to be a spring bean and use the init-method as shown below to actually start the socket server. Ths spring framework will automatically call it on bean instantiation.

An example configuration for a netty server could be like below:

<bean id="tcpServer" class="netty.NettyTCPServer"
        init-method="createServerBootstrap" destroy-method="stopServer">
        <property name="pipelineFactory" ref="pipelineFactory"></property>
</bean>

<bean id="pipelineFactory" class="netty.HandshakePipelineFactory">
        <lookup-method name="createHandshakeHandler" bean="handshakeHandler" />
        <property name="stringDecoder" ref="stringDecoder"></property>
        <property name="stringEncoder" ref="stringEncoder"></property>
        <property name="nulEncoder" ref="nulEncoder"></property>
        <property name="frameSize" value="256"></property>
</bean>