Create Maven and Gradle spring boot java projects in 5 mins

No introductions , just quick pointers of what is what of a simple spring boot application with two build tools.

Let's dive right into it.

Prerequisites

• Basic java knowledge, if there good else never mind you will pick it up on the way :)
• Install a good IDE , IntelliJ CE preferred, since it will help you to set everything up quickly
• JDK 11
• [optional] git bash in case you want to check out my sample repos with a sample rest endpoint

Thats all we are good to go.

So what is going to help us here to kickstart a new spring boot application is this beautiful ui spring provides us

https://start.spring.io/

You can pick and choose what type of project , packaging, java version etc. For the sake of this blog we are going to see both maven and gradle projects on java 11

Components

• Dependencies maven pom.xml (for maven dummies, pom.xml is a holy grail of a maven project where you will define anything and everything about build , deploy , etc [literally any task you want to achieve] of a project)

    <dependencies>
       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter</artifactId>
       </dependency>
       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-test</artifactId>
           <scope>test</scope>
       </dependency>
   </dependencies>
  

gradle build.gradle (much prettier counterpart of maven. pretty print officially likes gradle 😀)

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

• Spring Boot Application Create any public class and add below annotation

@SpringBootApplication
public class DemoApplication {

Lets see what this will do, remembering Phillip Webb, Stephane Nicoll, Andy Wilkinson (for them to have it explained kindly in the documentation)

Indicates a link to Configuration class that declares one or more @Bean methods and also triggers @EnableAutoConfiguration and @ComponentScan component scanning. This is a convenience annotation that is equivalent to declaring @Configuration, @EnableAutoConfiguration and @ComponentScan.

 SpringApplication.run(DemoApplication.class, args);

Above code will run the spring application, creating and refreshing a new ApplicationContext which is returned.

Also here we have added rest controller in the main class itself as below. You can have your own controller class and annotate it with @RestController and define the endpoints there.

@RestController
@SpringBootApplication
public class DemoApplication {

    @GetMapping("/hello")
    public String hello() {
        return "hello world";
    }
}

Run DemoApplication and try accessing your endpoint with http://localhost:8080/hello/. You will be able to see hello world as response in browser.

Congrats!! . You have successfully created a rest endpoint using spring boot.

Expert tip: spring-boot-starter-actuator dependency will additionally expose the actuator endpoint to monitor the health of your microservice. Try accessing http://localhost:8080/actuator/

Git links are provided below. Please feel free to clone and experiment.