How to use Swagger2 in spring boot

As we know every project required some documentation so that we get some help about the project. There is two option either you write yourself in a notepad or excel file about the project like details of endPoints in the project or use some tools that do documentation for you. I think second point is better we use some tool, so spring boot provide us a open source tool named Swagger2 for documentation. To use swagger2 in our application we have to follow below steps:

1. Add required dependency in your pom.xml file.
2. Create a Bean of Docker and provide your base package name .
3. Create a controller class and define some end points for which you want documentation information.
4. Run your application and hit the swagger2 URL.

Follow above Steps:

1- Add required dependency in your pom.xml file.

<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-web</artifactId>
</dependency>
	
<dependency>
 <groupId>io.springfox</groupId>
 <artifactId>springfox-swagger2</artifactId>
 <version>2.9.1</version>
</dependency>

<dependency>
 <groupId>io.springfox</groupId>
 <artifactId>springfox-swagger-ui</artifactId>
 <version>2.9.1</version>
</dependency>

2- Create a Bean of Docker and provide your base package name .

package com.example.demo;

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

import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

@SpringBootApplication
@EnableSwagger2
public class SwaggerSpringBootApplication {

	public static void main(String[] args) {
		SpringApplication.run(SwaggerSpringBootApplication.class, args);
	}
	
	  @Bean
	    public Docket productApi() {
	        return new Docket(DocumentationType.SPRING_WEB.SWAGGER_2).select()
					.apis(RequestHandlerSelectors.basePackage("com.example.demo")).build();
	    }

}

3- Create a controller class and define some end points for which you want documentation information.

package com.example.demo.controller;

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

@RestController
public class MyController {

	@GetMapping("/")
	public String entryPoint() {
		return "This is entry point";
	}
	
	@GetMapping("/api1")
	public String api1() {
		return "This is entry point";
	}
	
	@GetMapping("/api2")
	public String api2() {
		return "This is api2";
	}
}

4- Run your application and hit the swagger2 URL i.e.

http://localhost:8080/swagger-ui.html

After hitting the URL you will get a UI that dispplay the information about your end points and you can also test your api.

Complete Code on GitHub: Swagger2 in Spring Boot