added SparkUtils code

Author: debuglevel

build.gradle

@@ -1,37 +1,61 @@
 buildscript {
-    ext.kotlin_version = '1.2.41'
+    ext.kotlin_version = '1.2.50'
 
     repositories {
-        mavenCentral()
+        jcenter()
     }
     dependencies {
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
 
 plugins {
-    id 'java'
+    id 'java-library'
+    id 'org.jetbrains.kotlin.jvm' version "1.2.50"
+}
+
+compileKotlin {
+    kotlinOptions.jvmTarget = "1.8"
+}
+compileTestKotlin {
+    kotlinOptions.jvmTarget = "1.8"
 }
 
 group 'de.debuglevel.sparkutils'
 version '0.0.1-SNAPSHOT'
 
-apply plugin: 'kotlin'
-
 sourceCompatibility = 1.8
 
 repositories {
-    mavenCentral()
+    jcenter()
 }
 
 dependencies {
-    compile "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
-    testCompile group: 'junit', name: 'junit', version: '4.12'
-}
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
 
-compileKotlin {
-    kotlinOptions.jvmTarget = "1.8"
+    // Tests
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.2.0'
+    testRuntime 'org.junit.jupiter:junit-jupiter-engine:5.2.0'
+    testImplementation 'org.junit.jupiter:junit-jupiter-params:5.2.0'
+    testImplementation 'org.assertj:assertj-core:3.10.0'
+
+    // Logging
+    implementation 'io.github.microutils:kotlin-logging:1.4.9'
+//    compile 'org.slf4j:slf4j-api:1.7.5'
+//    compile 'org.slf4j:slf4j-simple:1.7.5'
+
+    // Spark (REST Server)
+    compileOnly 'com.sparkjava:spark-kotlin:1.0.0-alpha'
 }
-compileTestKotlin {
-    kotlinOptions.jvmTarget = "1.8"
-}
+
+//test {
+//    useJUnitPlatform()
+//
+//    testLogging {
+//        events "passed", "skipped", "failed"
+//    }
+//
+//    reports {
+//        html.enabled = true
+//    }
+//}

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,6 @@
+#Sat Jun 16 17:57:44 CEST 2018
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip

src/main/kotlin/de/debuglevel/sparkutils/port/SparkPortUtils.kt

@@ -0,0 +1,36 @@
+package de.debuglevel.microservices.spark
+
+import mu.KotlinLogging
+import spark.kotlin.port
+
+private val logger = KotlinLogging.logger {}
+
+/**
+ * Gets the value of the PORT environment variable, or 4567 if no such environment variable is set.
+ *
+ * @return value of the PORT environment variable, or 4567 if no such environment variable is set.
+ */
+private fun getEnvironmentPort(): Int {
+    // TODO: add more options to figure out a port configuration
+
+    val processBuilder = ProcessBuilder()
+    return if (processBuilder.environment()["PORT"] != null) {
+        Integer.parseInt(processBuilder.environment()["PORT"])
+    } else {
+        4567
+    }
+}
+
+/**
+ * Sets the port to a configured port.
+ *
+ * Currently, only the environment variable "PORT" is evaluated.
+ */
+fun configuredPort() {
+    // TODO: Spark fails silently if port is already taken. There should be thrown an exception
+
+    val port = getEnvironmentPort()
+    logger.info("Setting port to $port...")
+    port(port)
+    //logger.info("Setting port to $port succeeded.")
+}