Added some try for Template pattern

src/main/kotlin/oop/Template/HttpRequest.kt

@@ -0,0 +1,10 @@
+package oop.Template
+
+data class Body(val endpoint: String,
+                val parameter: String = "")
+
+sealed class HttpRequest(val body: Body) {
+  class Get(body: Body) : HttpRequest(body)
+  class Post(body: Body) : HttpRequest(body)
+  class Remove(body: Body) : HttpRequest(body)
+}

src/main/kotlin/oop/Template/Service.kt

@@ -0,0 +1,8 @@
+package oop.Template
+
+interface Service<T, U> {
+  fun findOne(id: U): T?
+  fun findAll() : Collection<T>
+  fun add(item: T): T
+  fun remove(id: U): Boolean
+}

src/main/kotlin/oop/Template/StringController.kt

@@ -0,0 +1,11 @@
+package oop.Template
+
+class StringController(val service: StringService) : TemplateController<String, String>(service) {
+  override fun findOne(id: String): String? = service.findOne(id)
+
+  override fun findAll(): Collection<String> = service.findAll()
+
+  override fun add(item: String): String = service.add(item)
+
+  override fun remove(id: String): Boolean = service.remove(id)
+}

src/main/kotlin/oop/Template/StringService.kt

@@ -0,0 +1,25 @@
+package oop.Template
+
+class StringService : Service<String, String> {
+
+  private val fakeList = mutableListOf(
+    Pair("1", "Test 1"),
+    Pair("2", "Test 2"),
+    Pair("3", "Test 3")
+  )
+
+  override fun findOne(id: String): String? =
+    fakeList.firstOrNull { it.first == id }?.second
+
+  override fun findAll(): Collection<String> =
+    fakeList.map { it.second }
+
+  override fun add(item: String): String {
+    val lastId = fakeList.last().first.toInt() + 1
+    fakeList.add(Pair(lastId.toString(), item))
+    return item
+  }
+
+  override fun remove(id: String): Boolean =
+    fakeList.remove(fakeList.find { it.first == id })
+}

src/main/kotlin/oop/Template/TemplateController.kt

@@ -0,0 +1,43 @@
+package oop.Template
+
+abstract class TemplateController<T, E>(private val service: Service<T, E>) {
+
+  abstract fun findOne(id: E) : T?
+  abstract fun findAll() : Collection<T>
+  abstract fun add(item: T) : T
+  abstract fun remove(id: E) : Boolean
+
+  fun handleRequest(request: HttpRequest) : String {
+    when (request) {
+
+      is HttpRequest.Get -> {
+        return handleGetRequest(request.body)
+      }
+
+      is HttpRequest.Post -> {
+        return handlePostRequest(request.body)
+      }
+
+      is HttpRequest.Remove -> {
+        return handleRemoveRequest(request.body)
+      }
+
+    }
+  }
+
+  private fun handleGetRequest(body: Body) : String =
+    when (body.endpoint) {
+      "findOne" -> findOne(body.parameter as E).toString()
+      "findAll" -> findAll().toString()
+      else -> "Error 404: Not Found"
+    }
+
+  private fun handlePostRequest(body: Body) : String =
+    if (body.endpoint == "add") add(body.parameter as T).toString()
+    else "Error 404: Not Found"
+
+  private fun handleRemoveRequest(body: Body) : String =
+    if (body.endpoint == "remove") remove(body.parameter as E).toString()
+    else "Error 404: Not Found"
+
+}