Mastering REST APIs in Spring Boot: A Comprehensive Guide for Quick and Efficient Development - Part 1

Create a Spring Boot Maven Project

1. Use Spring Initializr (https://start.spring.io/) or your IDE to create a new Maven project with the following settings:

   • Group: com.javakar
   • Artifact: javakar-static-api-example
   • Dependencies: Spring Web

2. Generate the project and download the zip file.

3. Extract the contents of the zip file to your preferred project location.

Project Structure

        Following snippet is showing the project structure, file and folder tree 

pom.xml File

Maven is a popular build automation and project management tool used primarily for Java projects. It simplifies the process of building, managing dependencies, and deploying applications.

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.7.14</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.javakar</groupId>
    <artifactId>javakar-static-api-example</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>javakar-static-api-example</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>11</java.version>
    </properties>
    <dependencies>
        <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>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

Create the StudentController.java class

We have annotated StudentController.java class with @RestController, which tells Spring that this class will handle web requests and will return the response in a format required for RESTful APIs.

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

import java.util.ArrayList;
import java.util.List;

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

    @GetMapping("/students")
    public List<Student> getAllStudents(){
        List<Student> students = new ArrayList<>();
        students.add(new Student(1, "Aamir", "aamir@aamir.com"));
        students.add(new Student(2, "Shayan", "shayan@shayan.com"));
        students.add(new Student(3, "Kashif", "kashif@kashif.com"));
        return students;
    }
}

The @RequestMapping("/api") annotation used in the above StudentController.java class specifies the base path for all endpoints.

The @GetMapping annotation is used to handle HTTP GET requests. The getAllStudents method returns a list of Student objects. In this example, the data is hardcoded, but in a real-world scenario, you would fetch this data from a database or another data source which we have done in part 3 of this series.

Create the Student.java class

This is a simple Java class representing a Student. It has private fields (id, name, and email) along with standard constructors and getter methods.

public class Student {

    private Integer id;
    private String name;
    private String email;

    public Student(Integer id, String name, String email) {
        this.id = id;
        this.name = name;
        this.email = email;
    }

    public Integer getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public String getEmail() {
        return email;
    }
}

Run the Spring Boot Application

This is the main application class annotated with @SpringBootApplication. It tells Spring Boot to start adding beans based on classpath settings. The main method launches the Spring Boot application.

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

@SpringBootApplication
public class JavakarStaticApiExampleApplication {

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

Check API response

Once your application starts successfully then hit this URL to get the response http://localhost:8080/api/students

[
    {
        "id": 1,
        "name": "Aamir",
        "email": "aamir@aamir.com"
    },
    {
        "id": 2,
        "name": "Shayan",
        "email": "shayan@shayan.com"
    },
    {
        "id": 3,
        "name": "Kashif",
        "email": "kashif@kashif.com"
    }
]