fix accept header evaluation

Author: mduesterhoeft

sample/build.gradle.kts

@@ -2,6 +2,7 @@ import com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 import com.github.jengelman.gradle.plugins.shadow.transformers.Log4j2PluginsCacheFileTransformer
 import java.net.URI
+import java.util.concurrent.TimeUnit.*
 
 buildscript {
     repositories {
@@ -66,4 +67,8 @@ tasks {
         dependsOn("test", "shadowJar")
         commandLine("serverless", "deploy")
     }
+}
+
+configurations.all {
+    resolutionStrategy.cacheChangingModulesFor(0, SECONDS)
 }

src/main/kotlin/com/github/mduesterhoeft/router/RequestHandler.kt

@@ -41,6 +41,7 @@ abstract class RequestHandler : RequestHandler<ApiRequest, ApiResponse> {
         val requestType = handler.reflect()!!.parameters.first().type.arguments.first().type?.classifier as KClass<*>
         return when (requestType) {
             Unit::class -> Unit
+            String::class -> input.body!!
             else -> objectMapper.readValue(input.body, requestType.java)
         }
     }