BAEL-2580 JVM Platform Annotations in Kotlin

core-kotlin/src/main/kotlin/com/baeldung/jvmannotations/Document.kt

@@ -0,0 +1,31 @@
+package com.baeldung.jvmannotations
+
+import java.util.*
+
+interface Document {
+
+    @JvmDefault
+    fun getType() = "document"
+}
+
+class TextDocument : Document {
+    override fun getType() = "text"
+
+    fun transformList(list : List<Number>) : List<Number> {
+        return list.filter { n -> n.toInt() > 1 }
+    }
+
+    fun transformListInverseWildcards(list : List<@JvmSuppressWildcards Number>) : List<@JvmWildcard Number> {
+        return list.filter { n -> n.toInt() > 1 }
+    }
+
+    var list : List<@JvmWildcard Any> = ArrayList()
+}
+
+class XmlDocument(d : Document) : Document by d
+
+fun main() {
+    val myDocument = TextDocument()
+    val myTextDocument = XmlDocument(myDocument)
+    println("${myDocument.getType()} ${myTextDocument.getType()}")
+}

core-kotlin/src/main/kotlin/com/baeldung/jvmannotations/HtmlDocument.java

@@ -0,0 +1,9 @@
+package com.baeldung.jvmannotations;
+
+public class HtmlDocument implements Document {
+
+    @Override
+    public String getType() {
+        return "HTML";
+    }
+}

core-kotlin/src/main/kotlin/com/baeldung/jvmannotations/Message.kt

@@ -0,0 +1,66 @@
+@file:JvmName("MessageHelper")
+@file:JvmMultifileClass //used
+package com.baeldung.jvmannotations
+
+import java.util.*
+
+@JvmName("getMyUsername")
+fun getMyName() : String {
+    return "myUserId"
+}
+
+object MessageBroker {
+    @JvmStatic
+    var totalMessagesSent = 0
+
+    const val maxMessageLength = 0
+
+    @JvmStatic
+    fun clearAllMessages() {
+    }
+
+    @JvmStatic
+    @JvmOverloads
+    @Throws(Exception::class)
+    fun findMessages(sender : String, type : String = "text", maxResults : Int = 10) : List<Message> {
+        if(sender.isEmpty()) {
+            throw Exception()
+        }
+        return ArrayList()
+    }
+}
+
+class Message {
+
+    // this would cause a compilation error since sender is immutable
+    // @set:JvmName("setSender")
+    val sender = "myself"
+
+    // this works as name is overridden
+    @JvmName("getSenderName")
+    fun getSender() : String = "from:$sender"
+
+    @get:JvmName("getReceiverName")
+    @set:JvmName("setReceiverName")
+    var receiver : String = ""
+
+    @get:JvmName("getContent")
+    @set:JvmName("setContent")
+    var text = ""
+
+    // generates a warning
+    @get:JvmName("getId")
+    private val id = 0
+
+    @get:JvmName("hasAttachment")
+    var hasAttachment = true
+
+    var isEncrypted = true
+
+    fun setReceivers(receiverNames : List<String>) {
+    }
+
+    @JvmName("setReceiverIds")
+    fun setReceivers(receiverNames : List<Int>) {
+    }
+}

core-kotlin/src/main/kotlin/com/baeldung/jvmannotations/MessageConverter.kt

@@ -0,0 +1,6 @@
+@file:JvmMultifileClass
+@file:JvmName("MessageHelper") //applies to all top level functions / variables / constants
+package com.baeldung.jvmannotations
+
+fun convert(message: Message) {
+}