How to make swagger-ui.html your app web-service’s index page

I was introduced to swagger api which is a very good tool for web service documentation. Considering that i build java application web-service using spring boot framework, it was very easy to integrate and it rendered my apis as expected but i had to view the swagger api doc page by calling the swagger-ui.html page as part of the url which was not ok for me because i was considering the web service consumers. How it wont be easy for them to remember that the url should include swagger-ui.html for them to view the web-service doc.

So, i decided to do something which is to ensure that when the consumers of the web-service call the context path of the application, they are automatically navigated to the swagger-ui.html page, this made me happy then i decided to share.

Please note that this is implemented in java using spring boot framework.

Please view below details

We need to add the dependency as usual.

<!-- swagger -->
<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>

Then i created a class for swagger configuration which i called the swaggerConfig.

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.bind.annotation.RestController;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

@Configuration
@EnableSwagger2
public class SwaggerConfig {

    @Bean
    public Docket api(){
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(getApiInfo())
                .select()
                .apis(RequestHandlerSelectors.withClassAnnotation(RestController.class))
                .paths(PathSelectors.any())
                .build();
    }

    private ApiInfo getApiInfo(){
        return new ApiInfoBuilder()
                .title("Simple app")
                .description("Simple app documentation page, This is for test purpose. like a testing field")
                .version("0.0.1")
                .contact(new Contact("Stob", "http://www.stob.com", "info@stob.com"))
                .build();
    }

}

With these done, we can view our swagger-ui.html page BUT we have to add to the url “/swagger-ui.html”, for example http://localhost:8080/swagger-ui.html instead of http://localhost:8080/ or http://localhost:8080 (our target)

To automatically navigate to the swagger-ui.html page, we use a request filter.

import org.apache.catalina.servlet4preview.http.HttpServletRequest;

import javax.servlet.*;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class MyFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        if (request.getRequestURI().equals("") || request.getRequestURI().equals("/")){
            response.sendRedirect(Constants.DOCUMENTATION_URL);
            return;
        }

        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {

    }
}
public interface Constants {

    String DOCUMENTATION_URL = "/swagger-ui.html";

}
@SpringBootApplication
public class SimipleWebappApplication {

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

    @Bean
    public FilterRegistrationBean filterRegistrationBean(){
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        MyFilter myFilter = new MyFilter();
        filterRegistrationBean.setFilter(myFilter);
        return filterRegistrationBean;
    }
}

Visit your api or application web-service swagger doc using the context path “http://localhost:8080/” or without the context path “http://localhost:8080”.

I hope this helps someone. Thank you.