Remoter

Remoter - An alternative to Android AIDL for Android Remote IPC services using plain java interfaces

Remoter makes developing android remote services intuitive without messing with AIDL.

Android IPC through AIDL

Android supports remote IPC using AIDL. This process of using “aidl” is painful and limited.

Some of the problems and limitations of AIDL are :

Unlike the intuitive way of defining an inteface defintions as an interface , AIDL forces you to define the interface in an “ .aidl ” file

, AIDL forces you to define the interface in an “ ” file The .aidl file is usually in a different folder than your normal source

You lose most of the IDE capability for the “ .aidl ”

” You can’t use an existing interface class and convert that to a remote interface – it has to be defined seperately as “.aidl”

Only limited predefined data types are supported in aidl

Any custom Parcelable class that you want to pass through the interface has to be defined again as another “.aidl” file!

No overloaded methods!- Methods with same name fail

Can’t extend an aidl with another

Can’t throw custom exceptions

Remoter - An intuitive way for Android IPC

Remoter solves the above problems in AIDL by allowing you to define the remote interface using plain java interface, and implement it using plain java implementation of the interface.

All you have to do is annotate the interface using @Remoter

@Remoter public interface ISampleService { ... }

No messy .aidl , just plain simple interface

, just plain simple Implement the interface directly using intuitive normal java way, instead of extending Stub

Fully interoperable with AIDL . Remoter creates the same serialized data as created by AIDL, so it is fully interoperable with AIDL

. Remoter creates the same serialized data as created by AIDL, so it is fully interoperable with AIDL Supports more data types than AIDL, everything supported by Parceler

Make an interface that extends other interfaces as @Remoter

Interface methods can throw any exceptions. Clients will get the same exception that is thrown.

Remoter interface can be templated

Remoter is an annotation processor that generates two helper classes during build time – a client side Proxy and a service side Stub that allows you to wrap your interface and implementation

that generates two helper classes during build time – a client side Proxy and a service side Stub that allows you to wrap your interface and implementation Support kotlin coroutines!

At the client side

Simply wrap the binder that you got from the ServiceConnection with the autogenerated Proxy for your interface

ISampleService sampleService = new ISampleService_Proxy ( binder );

At the service side

Wrap the implementation with the autogenerated Stub to covert it as a remote Binder and return that from your service

Binder binder = new ISampleService_Stub ( sampleServiceImpl );

That’s it!

Annotations

@Remoter Annotate on an interface to make it a remote interface

Annotate on an interface to make it a remote interface @ParamIn Mark an array or Parcelable parameter as an input only parameter( in of aidl). By default they are input and output (inout of aidl)

Mark an array or Parcelable parameter as an parameter( of aidl). By they are (inout of aidl) @ParamOut Mark an array or Parcelable parameter as an output only parameter( out of aidl).

Mark an array or Parcelable parameter as an parameter( of aidl). @Oneway Annotate on a method (in the @Remoter interface) with void return to make it an asynchronous method.

Annotate on a method (in the @Remoter interface) with void return to make it an asynchronous method. @NullableType Used to annotate a type parameter or suspend function return as nullable. See below for more details

Kotlin Support with suspend functions

Remoter supports Kotlin interfaces with suspend functions. If your interface (marked with @Remoter) has any suspend functions, then the generated Proxy and Stub will be in Kotlin, enabling to call your remoter service method from coroutines.

The suspend functions will be dispatched using the Dispatcher.IO context

Kotlin Proxy can be created using the optional constructor that accepts IServiceConnector which moves service connection to a suspendable coroutine

Kotlin Example

Define interface in kotlin as suspend

@Remoter interface ISampleService { /** * A suspend function which will be implemented by a service */ suspend fun authenticate ( userName : String , password : String ) : Boolean }

Include the depednecy for RemoterBuilder to take advantage of suspended service connection

implementation ' com . josesamuel : remoter-builder :< VERSION > '

From your coroutine, call the remote service call as follows

//From your coroutine context - //create service using serviceintent val service = ISampleService_Proxy ( context , SERVICE_INTENT ) //call the suspend function val authenticated = service . authenticate ( userName , password ) //The above call will - suspend the current context - connect to service , - make the remote call , all sequentially without blocking the calling thread !

No need to take care of service connection!

No need to move to background thread for service call and then to main thred to update UI!

Notes on Kotlin support

Add remoter-builder dependency to get support for suspendable service connection using IServiceConnector

vararg is not supported. Either use array or non suspend

If any return is nullable type on a suspend function, explicitly mark the method with @NullableType

If any types in a generic parameter is nullable, explicitly mnark those parameter with @NullableType optionally specifying which indexex of that type parameter are nullable

Getting Remoter

Gradle dependency

dependencies { implementation 'com.josesamuel:remoter-annotations:2.0.0' kapt 'com.josesamuel:remoter:2.0.0' //If using kotlin coroutines, include following //to make even the service connection simpler - implementation 'com.josesamuel:remoter-builder:2.0.0' }

License