RESTful Web Services Project with Spring Boot

Creating Hello World Service

Step 1: Now you need to create a HelloWorldController named class inside the com.codingninjas.server.main package.

Step 2: Now we need to define two things, i.e., Uniform Resource Identifier (URI) and GET method, whenever we create a web service. Create a helloWorld() method that returns the “Hello World!” string. We must add the @RestController annotation to spring MVC in order to instruct it to handle the REST request. It now has the ability to handle Rest requests.
 

package com.codingninjas.server.main;  
import org.springframework.web.bind.annotation.RequestMethod;  
import org.springframework.web.bind.annotation.RequestMapping;  
import org.springframework.web.bind.annotation.RestController;  

//Controller  
@RestController  
public class HelloWorldController   
{  
	// using hello-world as URI and GET method
	@RequestMapping(method=RequestMethod.GET, path="/hello-world")  
	public String helloWorld()  
	{  
		return "Hello World!";  
	}  
}  

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Instead of using @RequestMapping, we can use @GetMapping annotation to improve the code.
 

@GetMapping(path="/hello-world")  

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Step 3: Run the RestfulWebServiceApplication. It will display “Hello World!” on the browser.

Enhancing the Hello World Service to Return a Bean

In this section, we will generate a bean for helloWorld() method.

Step 1: First, create a helloWorldBean() method inside the HelloWorldController.java file. Return HelloWorldBean after Mapping URI to “/hello-world-bean”.

HelloWorldController.java  

package com.codingninjas.server.main;
import org.springframework.web.bind.annotation.RestController;  
import org.springframework.web.bind.annotation.GetMapping;  
//Controller  
@RestController  
public class HelloWorldController   
{  
	//using get method and hello-world URI  
	@GetMapping(path="/hello-world")  
	public String helloWorld()  
	{  
		return "Hello World!";  
	}  
	@GetMapping(path="/hello-world-bean")  
	public HelloWorldBean helloWorldBean()  
	{  
		return new HelloWorldBean("Hello World!");
	}  
}  

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Step 2: Create HelloWorldBean class and generate Getters and Setters. Also, generate toString().

Right-click -> Source -> Generate Getters and Setters -> check the box -> Ok

Right-click -> Source -> Generate toString().. -> Ok

HelloWorldBean.java
 

package com.codingninjas.server.main;  
public class HelloWorldBean   
{  
	public String msg;  
	//constructor of HelloWorldBean  
	public HelloWorldBean(String msg)  
	{  
		this.msg=msg;  
	}  
	//generating getters and setters  
	public String getMessage()  
	{  
		return msg;  
	}  
	public void setMessage(String msg)   
	{  
		this.msg = msg;  
	}  
	@Override  
	//generate toString  
	public String toString()   
	{  
		return String.format ("HelloWorldBean [msg=%s]", msg);  
	}  
}  

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Step 3: Launch the HelloWorldController. You will be redirected to localhost:8080/hello-world-bean.

This will return “Hello World!” in JSON format.

Frequently Asked Questions

What is a spring boot?

An open source Java-based framework Spring Boot is used to build micro Services. The Pivotal Team created it, and it's used to create standalone, production-ready spring apps.

Is spring boot a backend?

A backend framework Spring Boot has gained significant traction in the Java enterprise sector. It enables Java developers to easily and quickly begin creating web apps.

What is spring boot REST API?

A Java framework for creating web applications called Spring Boot was created on top of the Spring framework. You can construct REST APIs using only the bare minimum of configurations. Using Spring Boot for your REST APIs has a number of advantages, including No need for intricate XML setups.

What is the benefit of spring boot?

It greatly cuts down on development time and boosts output. It prevents the need to create a tonne of redundant XML configuration, annotations, and code. The Spring Ecosystem, which includes Spring JDBC, Spring ORM, Spring Data, Spring Security, etc., is very simple to integrate with the Spring Boot Application.

Why is REST architecture important?

REST allows us to achieve the architectural properties of performance, scalability, generality, simplicity, modifiability, and extensibility.

Conclusion

In this article, we have learned to build a RESTful web service project from scratch using Spring Boot.

You can also check how to carry out the STS Download.

Refer to our guided paths on Coding Ninjas Studio to learn more about DSA, Competitive Programming, JavaScript, System Design, etc.

Happy Coding!