Move to Kotlin

Moves the implementation from Java to Kotlin with as little breakage as possible.

BREAKING CHANGE: `JacksonParserFactory` had mistakenly been given the class `io.pleo.prop.guice`; it has been corrected to `io.pleo.prop.jackson`; minimum JDK version has been bumped to JDK11.

.github/workflows/build-n-publish.yml

@@ -33,10 +33,10 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-gradle-
 
-      - name: Set up JDK 8
+      - name: Set up JDK 17
         uses: actions/setup-java@v2
         with:
-          java-version: 8
+          java-version: 17
           distribution: 'adopt'
 
       - name: Gradle Build
@@ -58,11 +58,6 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
-          # Pin https://github.com/semantic-release/semantic-release to v17.4.7
-          # because https://github.com/cycjimmy/semantic-release-action currently runs on Node.js v12
-          # (see https://github.com/semantic-release/semantic-release/blob/master/docs/support/node-version.md)
-          # which is not supported by v18+
-          semantic_version: v17.4.7
           extra_plugins: |
             @semantic-release/changelog
             gradle-semantic-release-plugin

CODEOWNERS

@@ -0,0 +1,10 @@
+# Global owners, applies to all files with no specific rules defined later in this file. 
+# By default, this should be the stewards for the Moon.
+
+* @pleo-io/stewards-pegasus-backend
+
+# DevOps
+
+Dockerfile                                        @pleo-io/operations
+k8s                                               @pleo-io/operations
+

build.gradle

@@ -1,25 +1,55 @@
+
+buildscript {
+    ext {
+        kotlinVersion = "1.6.10"
+        kotlinCoroutinesVersion = "1.6.0"
+        kotlinGradlePluginVersion = "1.6.10"
+
+        kotlinterGradleVersion = "3.8.0"
+    }
+
+    repositories {
+        mavenLocal()
+        mavenCentral()
+    }
+
+    dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlinGradlePluginVersion"
+        classpath "org.jmailen.gradle:kotlinter-gradle:$kotlinterGradleVersion"
+    }
+}
+
+plugins {
+    id "org.jetbrains.kotlin.jvm" version "$kotlinVersion" apply false
+}
+
 allprojects {
     group = 'io.pleo'
 }
 
 subprojects {
     apply plugin: 'java-library'
+    apply plugin: "kotlin"
     apply plugin: 'maven-publish'
+    apply plugin: "org.jmailen.kotlinter"
 
-    sourceCompatibility = 1.8
-    targetCompatibility = 1.8
+    sourceCompatibility = 11
+    targetCompatibility = 11
 
     tasks.withType(JavaCompile) {
         options.encoding = 'UTF-8'
     }
 
-    repositories {
-        mavenLocal()
-        mavenCentral()
+    tasks.withType(org.jetbrains.kotlin.gradle.tasks.KotlinCompile) {
+        kotlinOptions {
+            jvmTarget = "11"
+            javaParameters = true
+            languageVersion = "1.6"
+        }
     }
 
     dependencies {
-        implementation 'org.slf4j:slf4j-api:1.7.32'
+        implementation 'org.slf4j:slf4j-api:1.7.33'
 
         testImplementation 'junit:junit:4.13.2'
         testImplementation 'org.mockito:mockito-core:4.2.0'
@@ -92,5 +122,4 @@ subprojects {
             }
         }
     }
-
 }