Improve kotlin code

Author: Flávio Ferreira

README.md

@@ -10,16 +10,22 @@ The user service must get data from the key value service to provide all informa
 * Maven
 
 ### About gRPC
+...
 
 ### About Kotlin
+...
 
 ## Try it
 
 ### Run key value service
+```
 mvn -pl kotlin-grpc-keyvalue-service exec:java
-
+```
 ### Run user service
+```
 mvn -pl kotlin-grpc-user-service exec:java
-
+```
 ### Run the client
+```
 mvn -pl kotlin-grpc-client exec:java
+```

kotlin-grpc-client/src/main/java/grpc/client/GrpcClient.kt

@@ -1,3 +1,5 @@
+package grpc.client
+
 import com.google.common.collect.Iterators
 import io.grpc.ManagedChannelBuilder
 import services.UserRequest
@@ -10,13 +12,13 @@ fun main(args: Array<String>) {
     val blockingStub = UserServiceGrpc.newBlockingStub(channel)
 
     try {
-        val users = Iterators.cycle("flavio", "carol", "ines")
+        val users = Iterators.cycle("radha", "kanti", "chanda", "kali")
         var i = 0
         while (users.hasNext() && i < 100) {
 
             val request = UserRequest.newBuilder().setName(users.next()).build()
 
-            println("Response from server: ${blockingStub.getUser(request)}")
+            println("Response from server:\n${blockingStub.getUser(request)}")
             i++
         }
 

kotlin-grpc-keyvalue-service/src/main/java/grpc/service/kv/GrpcServer.kt

@@ -1,15 +1,14 @@
 package grpc.service.kv
 
-
 fun main(args: Array<String>) {
 
     val server = io.grpc.ServerBuilder.forPort(15000).addService(KeyValueService()).build()
     server.start()
 
-    println("Server started")
+    println("Key value service started")
 
     Runtime.getRuntime().addShutdownHook(Thread() { println("Ups, JVM shutdown") })
     server.awaitTermination()
 
-    println("Server stopped")
+    println("Key value service stopped")
 }

kotlin-grpc-keyvalue-service/src/main/java/grpc/service/kv/KeyValueService.kt

@@ -1,46 +1,48 @@
 package grpc.service.kv
 
-import com.google.common.collect.ImmutableMap
-import com.google.common.collect.Maps
 import io.grpc.stub.StreamObserver
 import services.GetRequest
 import services.GetResponse
 import services.KeyValueServiceGrpc.KeyValueServiceImplBase
 import services.PutRequest
 import services.PutResponse
-import java.util.*
 
 class KeyValueService : KeyValueServiceImplBase() {
 
-    internal var store: MutableMap<String, String> = Maps.newHashMap(ImmutableMap.builder<String, String>()
-            .put("flavio.emailAddress", "flavio@gmail.com")
-            .put("flavio.country", "PT")
-            .put("flavio.active", "true")
-            .put("carol.emailAddress", "carol@gmail.com")
-            .put("carol.country", "UK")
-            .put("carol.active", "true")
-            .put("ines.emailAddress", "ines@gmail.com")
-            .put("ines.country", "Spain")
-            .put("ines.active", "false")
-            .build()
+    val names = listOf("radha", "kanti", "chanda", "kali")
+
+    internal var store: MutableMap<String, String> = hashMapOf(
+            "${names[0]}.email" to "${names[0]}@gmail.com",
+            "${names[0]}.country" to "Portugal",
+            "${names[0]}.active" to "true",
+            "${names[1]}.email" to "${names[1]}@gmail.com",
+            "${names[1]}.country" to "France",
+            "${names[1]}.active" to "true",
+            "${names[2]}.email" to "${names[2]}@gmail.com",
+            "${names[2]}.country" to "Spain",
+            "${names[2]}.active" to "true",
+            "${names[3]}.email" to "${names[3]}@gmail.com",
+            "${names[3]}.country" to "UK",
+            "${names[3]}.active" to "false"
     )
 
     override fun put(request: PutRequest, responseObserver: StreamObserver<PutResponse>) {
-        store.put(request.key, request.value)
+        store.put(request.key ?: throw IllegalArgumentException("key can not be null"),
+                request.value ?: throw IllegalArgumentException("value can not be null")
+        )
         responseObserver.onNext(PutResponse.newBuilder().build())
         responseObserver.onCompleted()
     }
 
     override fun get(request: GetRequest, responseObserver: StreamObserver<GetResponse>) {
-        val response = GetResponse.newBuilder()
-
-        val value = store[request.key]
-
-        if (value != null) {
-            response.value = value
-        }
-
-        responseObserver.onNext(response.build())
+        val response = GetResponse
+                .newBuilder()
+                .setValue(
+                        store[request.key ?: throw IllegalArgumentException("key can not be null")]
+                                ?: throw IllegalArgumentException("${request.key} key not found")
+                ).build()
+
+        responseObserver.onNext(response)
         responseObserver.onCompleted()
     }
 

kotlin-grpc-user-service/src/main/java/grpc/service/user/GrpcServer.kt

@@ -1,9 +1,9 @@
-import grpc.service.user.UserService
+package grpc.service.user
+
 import io.grpc.ManagedChannelBuilder
 import io.grpc.ServerBuilder
 import services.KeyValueServiceGrpc
 
-
 fun main(args: Array<String>) {
 
     val channel = ManagedChannelBuilder.forAddress("localhost", 15000).usePlaintext(true).build()
@@ -12,10 +12,10 @@ fun main(args: Array<String>) {
     val server = ServerBuilder.forPort(15001).addService(UserService(kvsClient)).build()
     server.start()
 
-    println("Server started")
+    println("User service started")
 
     Runtime.getRuntime().addShutdownHook(Thread() { println("Ups, JVM shutdown") })
     server.awaitTermination()
 
-    println("Server stopped")
+    println("User service stopped")
 }

kotlin-grpc-user-service/src/main/java/grpc/service/user/UserService.kt

@@ -13,26 +13,23 @@ class UserService(keyValue: KeyValueServiceBlockingStub) : UserServiceImplBase()
     private val keyValue = Preconditions.checkNotNull(keyValue)
 
     override fun getUser(request: UserRequest, responseObserver: StreamObserver<UserResponse>) {
-        val response = UserResponse.newBuilder()
 
-        response.name = request.name
-
-        response.emailAddress = keyValue.get(GetRequest.newBuilder()
-                .setKey(request.name + ".emailAddress")
-                .build())
-                .value
-
-        response.country = keyValue.get(GetRequest.newBuilder()
-                .setKey(request.name + ".country")
-                .build())
-                .value
-
-        response.active = java.lang.Boolean.valueOf(keyValue.get(GetRequest.newBuilder()
-                .setKey(request.name + ".active")
-                .build())
-                .value)!!
-
-        responseObserver.onNext(response.build())
+        fun getValue(key: String) = keyValue.get(
+                GetRequest
+                        .newBuilder()
+                        .setKey(request.name + key)
+                        .build() ?: throw IllegalArgumentException("key not found")
+        ).value
+
+        val response = UserResponse
+                .newBuilder()
+                .setName(request?.name ?: throw IllegalArgumentException("name can not be null"))
+                .setEmailAddress(getValue(".email"))
+                .setCountry(getValue(".country"))
+                .setActive(getValue(".active").toBoolean())
+                .build()
+
+        responseObserver.onNext(response)
         responseObserver.onCompleted()
     }