Swagger2 is an open source project used to generate the REST API documents for RESTful web services. It provides a user interface to access our RESTful web services via the web browser.
- To enable the Swagger2 in Spring Boot application, you need to add the following dependencies in our build configurations file.
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>2.7.0</version>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>2.7.0</version>
</dependency>
- For Gradle users, add the following dependencies in your build.gradle file.
compile group: 'io.springfox', name: 'springfox-swagger-ui', version: '2.7.0'
- Now, add the @EnableSwagger2 annotation in your main Spring Boot application.
The @EnableSwagger2 annotation is used to enable the Swagger2 for your Spring Boot application.
The code for main Spring Boot application is shown below −
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
@SpringBootApplication
@EnableSwagger2
public class SwaggerDemoApplication {
public static void main(String[] args) {
SpringApplication.run(SwaggerDemoApplication.class, args);
}
}
- Next, create Docket Bean to configure Swagger2 for your Spring Boot application. We need to define the base package to configure REST API(s) for Swagger2.
public Docket productApi() {
return new Docket(DocumentationType.SWAGGER_2).select()
.apis(RequestHandlerSelectors.basePackage("com.javahubpoint.swaggerdemo")).build();
}
- Now, add this bean in main Spring Boot application class file itself and your main Spring Boot application class will look as shown below −
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 SwaggerDemoApplication {
public static void main(String[] args) {
SpringApplication.run(SwaggerDemoApplication.class, args);
}
@Bean
public Docket productApi() {
return new Docket(DocumentationType.SWAGGER_2).select()
.apis(RequestHandlerSelectors.basePackage("com.javahubpoint.swaggerdemo")).build();
}
}
- Now, add the below Spring Boot Starter Web dependency in your build configuration file to write a REST Endpoints as shown below −
Maven users can add the following dependency in your pom.xml file −
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
Gradle users can add the following dependency in build.gradle file −
compile('org.springframework.boot:spring-boot-starter-web')
- Now, the code to build two simple RESTful web services GET and POST in Rest Controller file is shown here −
import java.util.ArrayList;
import java.util.List;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class SwaggerAPIController {
@RequestMapping(value = "/products", method = RequestMethod.GET)
public List<String> getProducts() {
List<String> productsList = new ArrayList<>();
productsList.add("Honey");
productsList.add("Almond");
return productsList;
}
@RequestMapping(value = "/products", method = RequestMethod.POST)
public String createProduct() {
return "Product is saved successfully";
}
}
The complete build configuration file is given below −
Maven – 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.javahubpoint</groupId>
<artifactId>swagger-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>swagger-demo</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</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>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger2</artifactId>
<version>2.7.0</version>
</dependency>
<dependency>
<groupId>io.springfox</groupId>
<artifactId>springfox-swagger-ui</artifactId>
<version>2.7.0</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Gradle – build.gradle
buildscript {
ext {
springBootVersion = '1.5.9.RELEASE'
}
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
}
}
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
group = 'com.javahubpoint'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
repositories {
mavenCentral()
} dependencies {
compile('org.springframework.boot:spring-boot-starter-web')
testCompile('org.springframework.boot:spring-boot-starter-test')
compile group: 'io.springfox', name: 'springfox-swagger2', version: '2.7.0'
compile group: 'io.springfox', name: 'springfox-swagger-ui', version: '2.7.0'
}
You can create an executable JAR file, and run the Spring Boot application by using the following Maven or Gradle commands.
For Maven, you can use the command shown here −
mvn clean install
After “BUILD SUCCESS”, you can find the JAR file under the target directory.
For Gradle, you can use the command as shown here −
gradle clean build
After “BUILD SUCCESSFUL”, you can find the JAR file under the build/libs directory.
Now, run the JAR file by using the command shown here −
java –jar <JARFILE>
Now, the application will start on the Tomcat port 8080 as shown −
Started Application on Tomcat Port 8080
Now, hit the URL in your web browser and see the Swagger API functionalities.
http://localhost:8080/swagger-ui.html
