How I can define a dynamic channels for int:router's "method" referenced

[dr_pompeii]

Hello Guys

I have the follow

<int:router id="router"
		input-channel="inicio"		
	        apply-sequence="true"
		resolution-required="true" 
		default-output-channel="noTypeMatchChannel"
		method="metodoRouter01"
		ref="myRouterSinAnnotationUno"
	/>

where the Java code is

public String metodoRouter01(Message<?> message){
		
	logger.info(".... message: {}", message);
		
	if(message.getPayload() instanceof String)
		return "stringChannel";
	else if(message.getPayload() instanceof Integer)
		return "integerChannel";
	else if(message.getPayload() instanceof ItemArticulo)
		return "instrumentoMusicalChannel";
	else
		return null;
}

I am checking each payload type to return the name of the channel. Since I use a String return type for the method used by the Router.

I could declared a static String[] type instead to get later a desired item through an index for each if/elseif scope to do the same approach

My problem is when I try to do the same with MessageChannel I mean, I must have the follow (code located in other class)

private DirectChannel stringChannel;
private DirectChannel integerChannel;
private DirectChannel instrumentoMusicalChannel;
	
@Value("#{stringChannel}")
public void setStringChannel(DirectChannel stringChannel) {
	this.stringChannel = stringChannel;
}

@Value("#{integerChannel}")
public void setIntegerChannel(DirectChannel integerChannel) {
	this.integerChannel = integerChannel;
}

@Value("#{instrumentoMusicalChannel}")
public void setInstrumentoMusicalChannel(DirectChannel instrumentoMusicalChannel) {
	this.instrumentoMusicalChannel = instrumentoMusicalChannel;
}

public MessageChannel metodoRouter01(Message<?> message){
		
	logger.info("... message: {}", message);
					
	if(message.getPayload() instanceof String){
		return stringChannel; 
	}
	else if(message.getPayload() instanceof Integer){			
		return integerChannel;			
	}
	else if(message.getPayload() instanceof ItemArticulo){			
		return instrumentoMusicalChannel;			
	}
        else
	        return null;
}

The code work fine, but I must declare each channel like a variable, it could be painful if my flow integration has 10 - 15 channels, exists a way to only declare for example just one

private DirectChannel directChannel;
	
public void setDirectChannel(DirectChannel directChannel) {
	this.directChannel = directChannel;
}

and in the if scope in someway just then indicate explicitly which Channel must be returned?

if(message.getPayload() instanceof String){
        //something to do get from my flow integration the stringChannel element
	return directChannel; 
}

Thanks in advanced

[oleg.zhurakousky]

Why aren't you using <intayload-type-router> with <mapping>?

[dr_pompeii]

Hello Oleg

Why aren't you using <intayload-type-router> with <mapping>?

I did and work fine

I am working with this approach only to test the part of Configuring a Router with Annotations where appear the follow snippet code

@Router
public MessageChannel route(Message message) {...}

@Router
public List<MessageChannel> route(Message message) {...}

@Router
public String route(Foo payload) {...}

@Router
public List<String> route(Foo payload) {...}

Since I am not calling some Service class, therefore I am doing explicitly this fake resolution like I shown on my first post

I hope you see my point

[oleg.zhurakousky]

Well if you doing it in code than you are essentially doing the same thing we do. In other words your if/else is an equivalent of <mapping>. Internally we use ChannelResolver strategy (BeanFactoryChannelResolver) but it does the same thing. I guess I am missing the question.

[dr_pompeii]

Hello Oleg

Well if you doing it in code than you are essentially doing the same thing we do. In other words your if/else is an equivalent of <mapping>. Internally we use ChannelResolver strategy (BeanFactoryChannelResolver) but it does the same thing

Yes, totally agree, I am just testing the other options available, of course with mapping is more cleaner but with int:router I could do about calling a method to later decide the output channel, I mean

public String metodoRouter01(Message<?> message){
		
	String x = this.someServiceBo(...);
		
	if(x....)
		return "xxx";
	else
		return "yyy";
}

I guess I am missing the question.

Yes

I have

private DirectChannel stringChannel;
private DirectChannel integerChannel;
private DirectChannel instrumentoMusicalChannel;
	
@Value("#{stringChannel}")
public void setStringChannel(DirectChannel stringChannel) {
	this.stringChannel = stringChannel;
}

@Value("#{integerChannel}")
public void setIntegerChannel(DirectChannel integerChannel) {
	this.integerChannel = integerChannel;
}

@Value("#{instrumentoMusicalChannel}")
public void setInstrumentoMusicalChannel(DirectChannel instrumentoMusicalChannel) {
	this.instrumentoMusicalChannel = instrumentoMusicalChannel;
}

I must declare each channel like a variable, it could be painful if my flow integration has 10 - 15 channels, I want to know if exists a way to only declare for example just only one variable

private DirectChannel directChannel;
	
public void setDirectChannel(DirectChannel directChannel) {
	this.directChannel = directChannel;
}

and latter in the if scope in someway just then indicate explicitly which Channel must assigned and returned?

      String result = this.someServiceBo(...);

       if(result ....){
             //something to do here 
             //to get from my flow integration the abcChannel element reference
             //and assign to directChannel    
	     return directChannel; 
       else if(result ...){
             //something to do here 
             //to get from my flow integration the xyzChannel element reference
             //and assign to directChannel    
	     return directChannel; 
       }
       ...
}

I edited the code above how a new version to avoid confuse with <intayload-type-router> with <mapping> behavior like you did, sorry for the confusion

Practically the directChannel is unware about which Channel it must represent by itself until the code enter to some if/else if an then there, this directChannel is assigned to the some desired channel from the flow integration, in this way I avoid to declare 4 or 10 different DirectChannels

Thank you

[Gary Russell]

	@Autowired
	Map<String, MessageChannel> channels;

For each entry in the map, the key is the bean name, the value is the channel.

[dr_pompeii]

Hello Gary

Thanks for the reply

I am working with this router and these channels

<int:channel id="dvdChannel" />	
<int:channel id="instrumentoMusicalChannel" />
...
<int:router id="router"
		input-channel="inicio"		
	        apply-sequence="true"
		resolution-required="true" 
		default-output-channel="noTypeMatchChannel"
		method="metodoRouter01"
		ref="myRouterConAnnotationUno"
/>

I am little confused about your code

@Autowired
Map<String, MessageChannel> channels;
For each entry in the map, the key is the bean name, the value is the channel.

With your approach Should I define a stand alone map collection in my flow integration file referring these channels?, Am I right?, or What did you do mean?

Thank you

[Gary Russell]

I was simply answering this question...

I must declare each channel like a variable, it could be painful if my flow integration has 10 - 15 channels, I want to know if exists a way to only declare for example just only one variable

You an use a map to get all the channels, mapped by their names. When your code decides which channel name to send to, simply lookup the map.

return channels.get("xyzChannel");

The point is, though, it's much easier to use the form of router that returns a channel name, not a MessageChannel object; as Oleg said, the framework will do the same thing and resolve the name to a channel.

Again, the general idea is not to tie your code (router or anything) to the framework. There is no need for your Router to know about channels (Direct or otherwise); just use names.

[dr_pompeii]

Hello Gary

Thanks again for your time and help

You an use a map to get all the channels, mapped by their names. When your code decides which channel name to send to, simply lookup the map.

I am totally agree, but is necessary create something like <util:map id="channels">
to let my class work in peace with

	@Autowired
	Map<String, MessageChannel> channels;

The point is, though, it's much easier to use the form of router that returns a channel name, not a MessageChannel object; as Oleg said, the framework will do the same thing and resolve the name to a channel.

I am agree with you, but I am just testing the other options to learn well the correct configuration and the most appropiate

Again, the general idea is not to tie your code (router or anything) to the framework. There is no need for your Router to know

Like my previous last sentence

Thanks a lot for your time

[Gary Russell]

is [ it ] necessary create something like <util:map id="channels">

No, spring will collect up all beans of that type in the context and create a Map for you and inject it here. It is the same as calling applicationContext.getBeansOfType(SomeType.class), which returns a Map<String,SomeType>.