Create a Simple Rest API in Java

A simple REST API in Java using Spring Boot – the most popular framework for building RESTful APIs in Java.

✅ Simple REST API in Java with Spring Boot

Spring Boot is a Java-based framework used to create standalone, production-ready, and easy-to-deploy Spring applications. It simplifies the process of building web applications and microservices with minimal configuration.

📌 Tools Needed

• Java 17 or later

• Maven

• Spring Boot

• Any IDE (Eclipse, IntelliJ, VS Code)

📁 Project Structure

simple-rest-api/
├── src/
│ ├── main/
│ │ ├── java/
│ │ │ └── com.example.demo/
│ │ │ ├── DemoApplication.java
│ │ │ └── controller/
│ │ │ └── HelloController.java
│ └── resources/
│ └── application.properties
└── pom.xml

Step 1: pom.xml

<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.example</groupId>
 <artifactId>demo</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <name>simple-rest-api</name>
 <description>Simple REST API in Java using Spring Boot</description>

 <properties>
 <java.version>17</java.version>
 </properties>

 <dependencies>
 <!-- Spring Boot Starter Web -->
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-web</artifactId>
 </dependency>

 <!-- Spring Boot Starter Test -->
 <dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-test</artifactId>
 <scope>test</scope>
 </dependency>
 </dependencies>

 <build>
 <plugins>
 <!-- Spring Boot Maven Plugin -->
 <plugin>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-maven-plugin</artifactId>
 </plugin>
 </plugins>
 </build>

</project>

Step 2: DemoApplication.java

package com.testingdocs.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {
 public static void main(String[] args) {
 SpringApplication.run(DemoApplication.class, args);
 }
}

🔧 Step 3: HelloController.java

package com.testingdocs.demo.controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api")
public class HelloController {

 @GetMapping("/hello")
 public String sayHello() {
 return "Hello, Welcome to Simple REST API in Java!";
 }
}

Step 4: application.properties

 

# Use default port 8080

 

▶️ How to Run

Use the terminal or your IDE and run:

mvn spring-boot:run

🌐 Test the API

Open your browser or use Postman/curl:

GET http://localhost:8080/api/hello

Response

Hello, Welcome to Simple REST API in Java!