The document discusses GRPC in Android. It provides an overview of GRPC, explaining that GRPC is Protobuf + RPC made by Google. It supports many languages and uses Protobuf format to transfer data. The document then outlines the step-by-step process to use GRPC in an Android project, including defining a Protobuf file, generating code, creating a GRPC server, adding libraries to Android, and making calls. It also mentions the four types of RPC methods and provides a reference link for more information on GRPC in Android.

1. GRPC in Android
Huỳnh Quang Thảo
Silicon Straits Saigon
Google Developer Expert on Android

2. SOAP

3. SOAP
- Simple Object Access Protocol.

4. SOAP
- Simple Object Access Protocol.
- Use XML Data format.

5. SOAP
- Simple Object Access Protocol.
- Use XML Data format.
- Human readable and editable.

6. XML DTD
- XML Document Type DeKinition

7. XML DTD
- XML Document Type DeKinition

8. XML DTD
- XML Document Type DeKinition.

9. XML DTD
- XML Document Type DeKinition.
- Useful for validation document.

10. XML DTD
- XML Document Type DeKinition.
- Useful for validation document.
- Useful for service discovery, convert schema
to objects (ie: Student, Person …)

11. Restful Service

12. Restful Service
- Using JSON Format.

13. Restful Service
- Using JSON Format.
- Human readable and editable.

14. Restful Service
- Using JSON Format.
- Human readable and editable.
- There are many libraries supporting Restful Service

15. Restful Service
- Using JSON Format.
- Human readable and editable.
- There are many libraries supporting Restful Service
- There are many tools supporting Restful Service.

17. {
"name": "Thao",
"school": "Le Hong Phong",
"year": 1993
}
{
"name": "Thao",
"school": "Le Hong Phong",
"class": "12CT"
}
1 2

18. {
"name": "Thao",
"school": "Le Hong Phong",
"year": 1993
}
{
"name": "Thao",
"school": "Le Hong Phong",
"class": "12CT"
}
1 2
- 1 is missed “class” attribute.
- 2 is missed “year” attribute.
- Both 1 and 2 are redundant attributes “year” and “class”
- …

19. Restful Service vs SOAP

20. Restful Service vs SOAP
Advantages
- More supporting tools and libraries.

21. Restful Service vs SOAP
Advantages
- More supporting tools and libraries.
- Easy to integrated to some languages (Javascript, Ruby)

22. Restful Service vs SOAP
Advantages
- More supporting tools and libraries.
- Easy to integrated to some languages (Javascript, Ruby)
Disadvantages
- Cannot validate data.

23. Restful Service vs SOAP
Advantages
- More supporting tools and libraries.
- Easy to integrated to some languages (Javascript, Ruby)
Disadvantages
- Cannot validate data.
- Cannot use for service discovery, transform schema to
methods.

24. RPC

25. RPC
- Remote Procedure Call.

26. RPC
- Remote Procedure Call.
- When a computer program causes a procedure to
execute in a different address space (commonly on
another computer on a shared network), which is
coded as if it were a local procedure call.

27. RPC

28. RPC// local object
Person p = new Person();
// update person
params = {id: p.id, name: p.name}
response = apiClient.updatePerson(params)
result_code = response.return_code
if (result_code == 200) { success }
else { retry }

29. RPC// local object
Person p = new Person();
// update person
params = {id: p.id, name: p.name}
response = apiClient.updatePerson(params)
result_code = response.return_code
if (result_code == 200) { success }
else { retry }
// we deKine updatePerson entry point somewhere else
host = localhost
port = 8080
updatePersonEntryPoint = /person/update

30. RPCClient
// local object
Person p = new Person();
p.name = ‘New Name’;
PersonService.updatePersonName(p);
// error. because server hasn’t deKined this method
PersonService.updatePersonYear(p);

31. RPCClient
// local object
Person p = new Person();
p.name = ‘New Name’;
PersonService.updatePersonName(p);
// error. because server hasn’t deKined this method
PersonService.updatePersonYear(p);
Server
class PersonService {
void updatePersonName(p) { …. }
void deletePerson(p) { …. }
}

32. Protobuf

33. JSON

34. JSON
<categories type="array">
<category>
<id>100</id>
<category-name>Category 1</category-name>
<category-description>Description 1</category-description>
</category>
<category>
<id>100</id>
<category-name>Category 1</category-name>
<category-description>Description 1</category-description>
</category>
</categories>
XML

35. 100,Category 1,Description 1
200,Category 2,Description 2
[id],[category name], [category description]
[id],[category name], [category description]

36. CSV
100,Category 1,Description 1
200,Category 2,Description 2
[id],[category name], [category description]
[id],[category name], [category description]

37. CSV
100,Category 1,Description 1
200,Category 2,Description 2
[id],[category name], [category description]
[id],[category name], [category description]
- JSON, XML are human-readable/editable format.

38. CSV
100,Category 1,Description 1
200,Category 2,Description 2
[id],[category name], [category description]
[id],[category name], [category description]
- JSON, XML are human-readable/editable format.
- Output footprint is large.
- Not efKicient for transferring data.

39. Protobuf
- Google's language-neutral, platform-neutral, extensible
mechanism for serializing structured dataOutput
footprint is large.

40. Protobuf
- Google's language-neutral, platform-neutral, extensible
mechanism for serializing structured dataOutput
footprint is large.
- Binary format.

41. Protobuf
- Google's language-neutral, platform-neutral, extensible
mechanism for serializing structured dataOutput
footprint is large.
- Binary format.
- EfKicient for transferring data.

44. syntax = "proto3";
package sphinyx;
service Remote {
rpc Accept(stream IncomingEnvelope) returns (stream
OutgoingEnvelope) {}
}
message OutgoingEnvelope {
string id = 1;
oneof message {
HelloResponse hello = 2;
TouchRequest touch = 12;
SwipeRequest swipe = 13;
SendTextRequest send_text = 14;
}
}
message IncomingEnvelope {
string id = 1;
oneof message {
HelloRequest hello = 2;
SetMousePointerResponse set_mouse_pointer = 10;
SetMouseResponse set_mouse = 11;
TouchResponse touch = 12;
SwipeResponse swipe = 13;
SendTextResponse send_text = 14;
}
}

45. GRPC

46. GRPC
GRPC = Protobuf + RPC made by Google

47. GRPC
GRPC = Protobuf + RPC made by Google
- is a RPC Protocol

48. GRPC
GRPC = Protobuf + RPC made by Google
- is a RPC Protocol
- Transfer data using Protobuf format

49. GRPC
GRPC = Protobuf + RPC made by Google
- is a RPC Protocol
- Transfer data using Protobuf format
- Made by Google: Support many languages

52. Step-by-Step

53. Step 1: deKine protobuf Kile
syntax = "proto3";
package sphinyx;
// This is the service for our API
service ChatService {
rpc Connect(ChatRequest) returns (ChatResponse) {}
rpc SendMessage(ChatRequest) returns (ChatResponse)
{}
}
message ChatRequest {
string id = 1;
string client = 2;
string message = 3;
}
message ChatResponse {
string id = 1;
string message = 2;
}

54. Step 2: Generate code for protobuf Kile
Ruby:
grpc_tools_ruby_protoc -I protos/ --ruby_out=lib --grpc_out=lib
protos/message.proto

55. require 'google/protobuf'
Google::Protobuf::DescriptorPool.generated_pool.build do
add_message "sphinyx.ChatRequest" do
optional :id, :string, 1
optional :client, :string, 2
optional :message, :string, 3
end
add_message "sphinyx.ChatResponse" do
optional :id, :string, 1
optional :message, :string, 2
end
end
module Sphinyx
ChatRequest =
Google::Protobuf::DescriptorPool.generated_pool.lookup("sphinyx.ChatRequest").msgclass
ChatResponse =
Google::Protobuf::DescriptorPool.generated_pool.lookup("sphinyx.ChatResponse").msgclass
end

56. require 'grpc'
require 'message_pb'
module Sphinyx
module ChatService
# This is the service for our API
class Service
include GRPC::GenericService
self.marshal_class_method = :encode
self.unmarshal_class_method = :decode
self.service_name = 'sphinyx.ChatService'
rpc :Connect, ChatRequest, ChatResponse
rpc :SendMessage, ChatRequest, ChatResponse
end
Stub = Service.rpc_stub_class
end
end

57. Step 3: Create GRPC from generated code
class GrpcChatServer < Sphinyx::ChatService::Service
@clients = []
def connect(hello_req, _unused_call)
puts "Hello Client:#{hello_req.client} with id=#{hello_req.id}"
new_id = "#{hello_req.client}-#{hello_req.id}"
Sphinyx::ChatResponse.new(id: new_id, message: "Hello #{new_id}")
end
end
def main
s = GRPC::RpcServer.new
s.add_http2_port('0.0.0.0:50051', :this_port_is_insecure)
s.handle(GrpcChatServer)
s.run_till_terminated
end
main

58. Step 4: Android. Insert Grpc libraries
Step 1: Add protobuf dependency at outer build.gradle file

59. Step 4: Android. Insert Grpc libraries
Step 2: Apply plugin protobuf

60. Step 4: Android. Insert Grpc libraries
Step 2: Apply plugin protobuf
Step 3: Add protobuf dependencies at inner build.gradle file

61. Step 4: Android. Insert Grpc libraries
Step 4: Define task for generating protobuf file

62. Step 5: Add protobuf Kile into main/proto
directory

63. Step 6: Using
Step 1: Define Grpc server
mChannel = ManagedChannelBuilder.forAddress(HOST, PORT)
.usePlaintext(true)
.build();
ChatServiceGrpc.ChatServiceBlockingStub stub = ChatServiceGrpc.newBlockingStub(mChannel);

64. Step 6: Using
Step 1: Define Grpc server
mChannel = ManagedChannelBuilder.forAddress(HOST, PORT)
.usePlaintext(true)
.build();
ChatServiceGrpc.ChatServiceBlockingStub stub = ChatServiceGrpc.newBlockingStub(mChannel);
Step 2: Define message
Message.ChatRequest message = Message.ChatRequest
.newBuilder()
.setId(ID)
.setClient("Android")
.build();

65. Step 6: Using
Step 3: Get result
Message.ChatResponse response = stub.connect(message);
String newId = response.getId();
Log.e("hqthao", response.getMessage());

66. DEMO

67. - There are 4 types of rpc method

68. - There are 4 types of rpc method
1. Simple GRPC
grpc GetFeature(Point) returns (Feature) {}

69. - There are 4 types of rpc method
1. Simple GRPC
grpc GetFeature(Point) returns (Feature) {}
2. Server side streaming
grpc ListFeatures(Rectangle) returns (stream Feature) {}

70. - There are 4 types of rpc method
1. Simple GRPC
grpc GetFeature(Point) returns (Feature) {}
2. Server side streaming
grpc ListFeatures(Rectangle) returns (stream Feature) {}
3. Client side streaming
grpc ListFeatures(stream Rectangle) returns (Feature) {}

71. - There are 4 types of rpc method
1. Simple GRPC
grpc GetFeature(Point) returns (Feature) {}
2. Server side streaming
grpc ListFeatures(Rectangle) returns (stream Feature) {}
3. Client side streaming
grpc ListFeatures(stream Rectangle) returns (Feature) {}
4. A bidirectional streaming RPC
grpc ListFeatures(stream Rectangle) returns (stream
Feature) {}

72. Reference
https://grpc.io/docs/quickstart/android.html

73. Q&A