Integration with TCP server (read/write string to socket)

[BartP]

Hi,

I want to integrate via Spring integration.
My standalone program connects to a ip address and port.

I write String commands to the socket. For example: "S*1,2,3,4;" always ended with the ';' character
And in a thread I read the incoming commands from server. All incoming commands are als Strings that ends with the ';' character.

In standalone code like this:

Sending data to socket:

String command = "!@@@!!@!@!@!@;"

this.socket = new Socket(this.host, this.port);
    this.in = this.socket.getInputStream();
    this.outputStreamWriter = new OutputStreamWriter(this.socket.getOutputStream());
    this.reader = new BufferedReader(
        new InputStreamReader(this.in, "UTF-8"));

this.outputStreamWriter.write(command, 0, command.length());

Reading data from socket in thread:

String buffer = "";

int character = this.reader.read();
         String c = String.valueOf((char) character);
         c.trim();
        if (!c.equals(";")) {
          buffer = buffer + c;

} else {
          buffer = buffer + c;
          String command = buffer;

         //do something
         buffer = "";
}

Now I want to integrate this functionallity in my spring appliction.
I can use this:

http://xebee.xebia.in/2010/11/01/dat...g-integration/

But I don't found an example how to write my custom class to write and read the socket.
Can someone help me with that?

custom-socket-reader-class-name="CustomClass"
custom-socket-writer-class-name="CustomClass"

[Gary Russell]

That blog is a little out of date; see the documentation http://static.springsource.org/sprin...e/html/ip.html and the tcp sample https://github.com/SpringSource/spri...-client-server

All you need is a custom serializer/deserializer. For this application, it might be as simple as subclassing ByteArraySingleTerminatorSerializer, in the same way that https://github.com/garyrussell/sprin...erializer.java does, but using ";" instead of 0x0a.

Note: this is available in the upcoming 2.2 release (currently at release candidate 2 - 2.2.0.RC2).

For earlier versions, you'll need to clone the code.

[BartP]

Ok thanks!
So I add this configuration to my application-context.xml

	<int-ip:tcp-connection-factory id="client"
		type="client" host="localhost" port="5555" single-use="true"
		so-timeout="10000" />

	<int-ip:tcp-outbound-channel-adapter
		id="outboundClient" channel="input" connection-factory="client" />


	<int:channel id="input" />

This means that when a message received on channel "input", it will open a socket to localhost port 5555 and write the message to that socket. yes?

I use MessagingTemplate like this:

MessagingTemplate messagingTemplate = new MessagingTemplate();
    messagingTemplate.send("input", new GenericMessage<String>(command));

I got this exception:

Caused by: java.lang.IllegalStateException: No 'channelResolver' specified for MessagingTemplate. Unable to invoke methods with a channel name argument.
	at org.springframework.util.Assert.state(Assert.java:384)
	at org.springframework.integration.core.MessagingTemplate.getRequiredChannelResolver(MessagingTemplate.java:337)
	at org.springframework.integration.core.MessagingTemplate.resolveChannelName(MessagingTemplate.java:353)
	at org.springframework.integration.core.MessagingTemplate.send(MessagingTemplate.java:153)
	at nl.eleqtron.qvisual.spring.service.GiaBusServiceImpl.sendCommand(GiaBusServiceImpl.java:13)
	at nl.eleqtron.qvisual.vaadin.ui.MainWindow$1.buttonClick(MainWindow.java:48)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

Any idea?

[Gary Russell]

When you create a MessagingTemplate manually (rather than by declaring it as a bean) you can't send by channel name by default. You either have to send to a channel reference (e.g. @Autowire private MessageChannel input; ) or provide it with a channel resolver, or declare it as a <bean/> and @Autowire private MessagingTemplate template; (and Spring will wire up the template for you to enable sending by channel name).

However, it's much better to isolate your sending code from Spring Integration by using a Messaging Gateway...

http://static.springsource.org/sprin...r.html#gateway