Upgrade to JDK 16 and Kotlin 1.3.21

samples/java/build.gradle

@@ -9,6 +9,11 @@ defaultTasks 'run'
 
 mainClassName = 'net.thauvin.erik.pinboard.samples.JavaExample'
 
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
+
 repositories {
     mavenLocal()
     mavenCentral()

samples/java/gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.0.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.1.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

samples/java/gradlew

@@ -72,7 +72,7 @@ case "`uname`" in
   Darwin* )
     darwin=true
     ;;
-  MINGW* )
+  MSYS* | MINGW* )
     msys=true
     ;;
   NONSTOP* )