Merge pull request #951 from tomekl007/BAEL-382_kotlin

BAEL-382 kotlin

kotlin/pom.xml

@@ -0,0 +1,65 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.baeldung</groupId>
+    <artifactId>kotlin</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-stdlib</artifactId>
+            <version>${kotlin-stdlib.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.jetbrains.kotlin</groupId>
+            <artifactId>kotlin-test-junit</artifactId>
+            <version>${kotlin-test-junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
+        <testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
+        <plugins>
+            <plugin>
+                <artifactId>kotlin-maven-plugin</artifactId>
+                <groupId>org.jetbrains.kotlin</groupId>
+                <version>${kotlin-maven-plugin.version}</version>
+                <executions>
+                    <execution>
+                        <id>compile</id>
+                        <goals>
+                            <goal>compile</goal>
+                        </goals>
+                    </execution>
+
+                    <execution>
+                        <id>test-compile</id>
+                        <goals>
+                            <goal>test-compile</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <junit.version>4.12</junit.version>
+        <kotlin-test-junit.version>1.0.4</kotlin-test-junit.version>
+        <kotlin-stdlib.version>1.0.4</kotlin-stdlib.version>
+        <kotlin-maven-plugin.version>1.0.4</kotlin-maven-plugin.version>
+    </properties>
+
+</project>

kotlin/src/main/kotlin/com/baeldung/kotlin/Example1.kt

@@ -0,0 +1,5 @@
+package com.baeldung.kotlin
+
+fun main(args: Array<String>){
+    println("hello word")
+}

kotlin/src/main/kotlin/com/baeldung/kotlin/Item.kt

@@ -0,0 +1,14 @@
+package com.baeldung.kotlin
+
+open class Item(val id: String, val name: String = "unknown_name") {
+    open fun getIdOfItem(): String {
+        return id
+    }
+}
+
+class ItemWithCategory(id: String, name: String, val categoryId: String) : Item(id, name) {
+    override fun getIdOfItem(): String {
+        return id + name
+    }
+}
+

kotlin/src/main/kotlin/com/baeldung/kotlin/ItemService.kt

@@ -0,0 +1,66 @@
+package com.baeldung.kotlin
+
+import java.util.*
+
+class ItemService {
+    fun findItemNameForId(id: String): Item? {
+        val itemId = UUID.randomUUID().toString()
+        return Item(itemId, "name-$itemId")
+    }
+}
+
+class ItemManager(val categoryId: String, val dbConnection: String) {
+    var email = ""
+
+    constructor(categoryId: String, dbConnection: String, email: String)
+    : this(categoryId, dbConnection) {
+        this.email = email
+    }
+
+    fun isFromSpecificCategory(catId: String): Boolean {
+        return categoryId == catId
+    }
+
+    fun makeAnalyisOfCategory(catId: String): Unit {
+        val result = if (catId == "100") "Yes" else "No"
+        println(result)
+
+    }
+}
+
+fun main(args: Array<String>) {
+    val numbers = arrayOf("first", "second", "third", "fourth")
+
+    var concat = ""
+    for (n in numbers) {
+        concat += n
+    }
+
+    var sum = 0
+    for (i in 2..9) {
+        sum += i
+    }
+
+    val firstName = "Tom"
+    val secondName = "Mary"
+    val concatOfNames = "$firstName + $secondName"
+    println("Names: $concatOfNames")
+
+    val itemManager = ItemManager("cat_id", "db://connection")
+    val result = "function result: ${itemManager.isFromSpecificCategory("1")}"
+    println(result)
+
+    val number = 2
+    if (number < 10) {
+        println("number less that 10")
+    } else if (number > 10) {
+        println("number is greater that 10")
+    }
+
+    val name = "John"
+    when (name) {
+        "John" -> println("Hi man")
+        "Alice" -> println("Hi lady")
+    }
+
+}

kotlin/src/main/kotlin/com/baeldung/kotlin/ListExtension.kt

@@ -0,0 +1,14 @@
+package com.baeldung.kotlin
+
+import java.util.concurrent.ThreadLocalRandom
+
+class ListExtension {
+    fun <T> List<T>.random(): T? {
+        if (this.isEmpty()) return null
+        return get(ThreadLocalRandom.current().nextInt(count()))
+    }
+
+    fun <T> getRandomElementOfList(list: List<T>): T? {
+        return list.random()
+    }
+}

kotlin/src/test/kotlin/com/baeldung/kotlin/ItemServiceTest.kt

@@ -0,0 +1,20 @@
+package com.baeldung.kotlin
+
+import org.junit.Test
+import kotlin.test.assertNotNull
+
+class ItemServiceTest {
+    @Test
+    fun givenItemId_whenGetForOptionalItem_shouldMakeActionOnNonNullValue() {
+        //given
+        val id = "item_id"
+        val itemService = ItemService()
+
+        //when
+        val result = itemService.findItemNameForId(id)
+
+        //then
+        assertNotNull(result?.let { it -> it.id })
+        assertNotNull(result!!.id)
+    }
+}

kotlin/src/test/kotlin/com/baeldung/kotlin/ListExtensionTest.kt

@@ -0,0 +1,19 @@
+package com.baeldung.kotlin
+
+import com.baeldung.kotlin.ListExtension
+import org.junit.Test
+import kotlin.test.assertTrue
+
+class ListExtensionTest {
+    @Test
+    fun givenList_whenExecuteExtensionFunctionOnList_shouldReturnRandomElementOfList(){
+        //given
+        val elements = listOf("a", "b", "c")
+
+        //when
+        val result = ListExtension().getRandomElementOfList(elements)
+
+        //then
+        assertTrue(elements.contains(result))
+    }
+}

pom.xml

@@ -68,6 +68,8 @@
         <module>jsoup</module>
         <module>junit5</module>
 
+        <module>kotlin</module>
+
         <module>log-mdc</module>
         <module>log4j</module>
         <module>log4j2</module>