GWT how can I reduce the size of code serializers for RPC calls

Question

I found that the more than 60% of the javaScript code generated by GWT on my application is for RPC serializers. Also I found that serializers are not shared between service

Answer 1

As far as I understand, the GWT code generation is supposed to supply concrete implementations of an interface. This implementation is then transformed into javascript for specific permutations.

Your sample, on the other hand, is replacing one interface with the other. If you see it from GWT compiler's eyes, perhaps you will see the problem with this configuration.

Suppose, you are the GWT compiler, and you see following line in client side code that you are converting into JavaScript

AccountingServiceAsync accountingServiceAsync = (AccountingServiceAsync) GWT.create(AccountingService.class);
accountingServiceAsync.recordTransaction(transaction,callback);

So you need to find out what should happen, at line 2. Specifically, you need to know where to find implementation of accountingServiceAsync.recordTransaction(). So you go looking into all your configuration to find if there is a rule specifying which implementation class should be used for AccountingService (not Async). But sadly you don't find any. But then you notice that AccountingService is also a RemoteService. So you dive into your configuration again. And, aha, there it is, a rule specifying that you can generate RemoteService implementations with ServiceInterfaceProxyGenerator. You happily hand over the task of providing an implementation of AccountingService to ServiceInterfaceProxyGenerator.

But suppose instead of this happy ending, your configuration tells you that AccountingService can be replaced with GenericService, and you say, "hey cool, bring it on". But just then you find out that GenericService is also an interface. Clearly, you'll be turned off, saying "now, what am I going to with another interface, all I needed was an implementation of AccountingService". At this point you'd want to get even with the programmer by throwing a cryptic error at him.

So, far all this explains why your solution (theoretically) won't work . As far as your actual concern of bloated javascript, I am amazed that this problem even exists given the amount of effort that GWT folks put in optimizing the compiled JavaScript. How did you tested your compiled output for duplication?