Spring Boot Gradle Plugin

Introduction

The Spring Boot Gradle Plugin is an essential tool for building Spring Boot applications using the Gradle build system. It simplifies the process of packaging and running your Spring Boot applications by providing various useful tasks and configurations. This take focuses on how to utilize the Spring Boot Gradle plugin for Kotlin-based Spring Boot projects.

Solution

Applying the Spring Boot Gradle Plugin

Description: The Gradle build script requires the Spring Boot plugin to apply various configurations and tasks.

Sample Code:

plugins {
    id("org.springframework.boot") version "2.5.4"
    kotlin("jvm") version "1.5.21"
    kotlin("plugin.spring") version "1.5.21"
}

dependencies {
    implementation("org.springframework.boot:spring-boot-starter-web")
    implementation("org.springframework.boot:spring-boot-starter-data-jpa")
    implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
    runtimeOnly("com.h2database:h2")
    testImplementation("org.springframework.boot:spring-boot-starter-test")
}

Advantages:

Reduces the boilerplate code by providing default configurations.
Ensures compatibility by coordinating dependency versions automatically.

Disadvantages:

Relies on the correct plugin versions being applied.

Running the Application

Description: Use the bootRun task to start the Spring Boot application from the command line.

Sample Code:

./gradlew bootRun

Output:

> Task :bootRun
Starting the MyApplication using Java 11...
2021-08-30 10:15:42.715  INFO 1 --- [           main] com.example.demo.MyApplication           : Starting MyApplication v0.0.1-SNAPSHOT using Java 11 with PID 1 (/app/classes started by root in /)
2021-08-30 10:15:42.718  INFO 1 --- [           main] com.example.demo.MyApplication           : No active profile set, falling back to default profiles: default
2021-08-30 10:15:43.158  INFO 1 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Bootstrapping Spring Data JPA repositories in DEFAULT mode.
2021-08-30 10:15:43.200  INFO 1 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 36 ms. Found 1 JPA repository interfaces.
2021-08-30 10:15:43.386  INFO 1 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2021-08-30 10:15:43.398  INFO 1 --- [           main] com.example.demo.MyApplication           : Started MyApplication in 0.869 seconds (JVM running for 1.211)

Advantages:

Efficiently runs the application in a development environment.
Automatically restarts the application for changes when used with Spring Boot DevTools.

Disadvantages:

May consume significant resources and time during continuous development.

Building and Packaging

Description: Use the bootJar task to create an executable JAR file containing the application and all its dependencies.

Sample Code:

./gradlew bootJar

Output:

> Task :bootJar
Building jar: /path/to/build/libs/demo-0.0.1-SNAPSHOT.jar

Advantages:

Produces a ready-to-run JAR file, simplifying deployment.
Encapsulates application code and dependencies in a single JAR file.

Disadvantages:

Resulting JAR file can be quite large due to embedded dependencies.

Running Tests

Description: Use the test task to run all unit tests in the project.

Sample Code:

./gradlew test

Output:

> Task :test

 com.example.demo.MyApplicationTests > contextLoads() PASSED

Advantages:

Ensures application correctness and stability.
Integrates with Continuous Integration systems easily.

Disadvantages:

May slow down the build process if there are many tests.

spring boot gradle plugin