RESTful API using Spring Boot

In this post, we are going to see how to implement RESTful Web Services using Spring Boot.
Project Structure:

Tools & Technologies:

• Java 8
• Maven 3.0.3
• Spring Boot 1.2.5.RELEASE

Maven Configuration:
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.ranga</groupId>
    <artifactId>SpringBootRestAPIExample</artifactId>
    <version>1.0.0-SNAPSHOT</version>

    <!-- Inherit defaults from Spring Boot -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.2.5.RELEASE</version>
    </parent>

    <dependencies>  
        <!-- Get the dependencies of a web application -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
    
</project>

RestController class
GreetingContoller.java

package com.ranga.greeting.controller;

import java.util.concurrent.atomic.AtomicLong;

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

import com.ranga.greeting.Greeting;
/**
 * Used for handling the greeting RESTFul request.
 * @author Ranga Reddy
 * @version 1.0
 * @since Aug 20, 2015
 */
@RestController
public class GreetingController {
    private static final String template = "Hello, %s!";
    private final AtomicLong counter = new AtomicLong();

    @RequestMapping("/greeting")
    public Greeting greeting(@RequestParam(value="name", defaultValue="Ranga") String name) {
        return new Greeting(counter.incrementAndGet(),
                            String.format(template, name));
    }
}

Greeting Response class:
Greeting.java

package com.ranga.greeting;

/**
 * Used to display the Response.
 * 
 * @author Ranga Reddy
 * @version 1.0
 * @since Aug 20, 2015
 */
public class Greeting {
    
    private long id;
    private String name;

    /** Default Greeting Constructor */
    public Greeting() {
        super();
    }
    
    /** Parameterized Greeting Constructor */
    public Greeting(long id, String name) {
        this.id = id;
        this.name = name;
    }

    /**
     * @return the id
     */
    public long getId() {
        return id;
    }

    /**
     * @param id the id to set
     */
    public void setId(long id) {
        this.id = id;
    }

    /**
     * @param name the name to set
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * @return the name
     */
    public String getName() {
        return name;
    }
    
    @Override
    public String toString() {
        return "Greeting [id=" + id + ", name=" + name + "]";
    }
}

Client Application

Application.java

package com.ranga.main;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

/**
 * Main application to run boot application.
 * 
 * @author Ranga Reddy
 * @version 1.0
 */
@SpringBootApplication
@ComponentScan(basePackages="com.ranga")
public class Application {
        public static void main(String[] args) throws Exception {
        SpringApplication.run(Application.class, args);
    }
}

Run the Client Application and open the browser enter the following url:
http://localhost:8080/greeting

http://localhost:8080/greeting?name=Ranga Reddy