Following this Kotlin Spring BOOT App does not work, - spring

Question

I am following this tutorial:
https://kotlinlang.org/docs/jvm-spring-boot-restful.html#proceed-to-the-next-tutorial
Its a nice step by step for sure. My intelliJ project compiles and runs.
THis is my build file:
import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
plugins {
id("org.springframework.boot") version "2.4.8"
id("io.spring.dependency-management") version "1.0.11.RELEASE"
kotlin("jvm") version "1.4.32"
kotlin("plugin.spring") version "1.4.32"
}
group = "com.example.itemtracker"
version = "0.0.1-SNAPSHOT"
java.sourceCompatibility = JavaVersion.VERSION_1_8
repositories {
mavenCentral()
mavenLocal()
}
dependencies {
implementation("org.springframework.boot:spring-boot-starter")
implementation("org.jetbrains.kotlin:kotlin-reflect")
implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
testImplementation("org.springframework.boot:spring-boot-starter-test")
implementation("org.springframework:spring-web:5.3.8")
implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.4.1")
implementation("org.springframework.boot:spring-boot-starter-tomcat:2.5.0")
}
tasks.withType<KotlinCompile> {
kotlinOptions {
freeCompilerArgs = listOf("-Xjsr305=strict")
jvmTarget = "1.8"
}
}
tasks.withType<Test> {
useJUnitPlatform()
}
Everything else looks like this tutorial.
Problem is when i enter localhost:8080 - i am getting this 404. The controller is in the same class. I have no idea why a 404 occurs.
Does anyone have any idea why this occurs?
Update:
I created another Kotlin project that uses Maven and it works. But the Gradle version still is not working.
POM Is:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://maven.apache.org/POM/4.0.0"
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>
<artifactId>mainModule</artifactId>
<groupId>me.scmacdon</groupId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>mainModule</name>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.4.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<kotlin.code.style>official</kotlin.code.style>
<kotlin.compiler.jvmTarget>1.8</kotlin.compiler.jvmTarget>
</properties>
<repositories>
<repository>
<id>mavenCentral</id>
<url>https://repo1.maven.org/maven2/</url>
</repository>
</repositories>
<build>
<sourceDirectory>src/main/kotlin</sourceDirectory>
<testSourceDirectory>src/test/kotlin</testSourceDirectory>
<plugins>
<plugin>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-maven-plugin</artifactId>
<version>1.4.32</version>
<executions>
<execution>
<id>compile</id>
<phase>compile</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
<execution>
<id>test-compile</id>
<phase>test-compile</phase>
<goals>
<goal>test-compile</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.2</version>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-test-junit</artifactId>
<version>1.4.32</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-stdlib-jdk8</artifactId>
<version>1.4.32</version>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-api</artifactId>
<version>5.4.2</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-reflect</artifactId>
<version>1.1.51</version>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<version>5.4.2</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.platform</groupId>
<artifactId>junit-platform-commons</artifactId>
<version>1.4.0</version>
</dependency>
<dependency>
<groupId>org.junit.platform</groupId>
<artifactId>junit-platform-launcher</artifactId>
<version>1.4.0</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.5</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
</project>

Answer 1

The following Gradle build file solved this issue:
import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
plugins {
id("org.springframework.boot") version "2.4.8"
id("io.spring.dependency-management") version "1.0.11.RELEASE"
kotlin("jvm") version "1.4.32"
kotlin("plugin.spring") version "1.4.32"
}
group = "com.example"
version = "0.0.1-SNAPSHOT"
java.sourceCompatibility = JavaVersion.VERSION_11
repositories {
mavenCentral()
}
dependencies {
implementation("org.springframework.boot:spring-boot-starter-data-jdbc")
implementation("org.springframework.boot:spring-boot-starter-web")
implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
implementation("org.jetbrains.kotlin:kotlin-reflect")
implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
runtimeOnly("com.h2database:h2")
testImplementation("org.springframework.boot:spring-boot-starter-test")
}
tasks.withType<KotlinCompile> {
kotlinOptions {
freeCompilerArgs = listOf("-Xjsr305=strict")
jvmTarget = "1.8"
}
}
tasks.withType<Test> {
useJUnitPlatform()
}