Add signing configuration / build Javadoc Jar and Sources Jar

Author: jjohannes

build.gradle.kts

@@ -12,6 +12,8 @@ version = "0.1"
 
 java {
     toolchain.languageVersion = JavaLanguageVersion.of(17)
+    withSourcesJar()
+    withJavadocJar()
 }
 
 tasks.compileJava {
@@ -65,6 +67,16 @@ publishing {
     }
 }
 
+signing {
+    if (providers.gradleProperty("sign").getOrElse("false").toBoolean()) {
+        useInMemoryPgpKeys(
+            providers.environmentVariable("SIGNING_KEY").getOrNull(),
+            providers.environmentVariable("SIGNING_PASSPHRASE").getOrNull()
+        )
+        sign(publishing.publications["maven"])
+    }
+}
+
 nmcp {
     publish("maven") {
         username = providers.environmentVariable("MAVEN_CENTRAL_USERNAME")