Swagger with Spring Boot 2.0 leads to 404 error page

I was able to make it work with Spring boot version 2.0.4.RELEASE and this blog post:

I added these dependencies:

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger2</artifactId>
    <version>2.9.2</version>
</dependency>

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger-ui</artifactId>
    <version>2.9.2</version>
</dependency>

And this configuration file:

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

@Configuration
@EnableSwagger2
public class SpringFoxConfig {
    @Bean
    public Docket apiDocket() {
        return new Docket(DocumentationType.SWAGGER_2)
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build();
    }
}

And it worked.

The Swagger UI can be reached at /swagger-ui.html#

Please check the reference: https://springfox.github.io/springfox/docs/current/

“2.1.3. Migrating from existing 2.x version”

You can remove springfox-swagger2 and springfox-swagger-ui from your pom.xml and add springfox-boot-starter instead (for example version 3.0.0). Also you can remove the @EnableSwagger2 annotations

And: “swagger-ui location has moved from http://host/context-path/swagger-ui.html to http://host/context-path/swagger-ui/index.html OR http://host/context-path/swagger-ui/ for short. This makes it work much better with pulling it as a web jar and turning it off using configuration properties if not needed.”

First add SwaggerConfig.java file at the same package of your springboot file like the following example.

@Configuration
@EnableSwagger2
@EnableWebMvc
public class SwaggerConfig extends WebMvcConfigurerAdapter {                                    
    @Bean
    public Docket api() { 
        return new Docket(DocumentationType.SWAGGER_2)  
          .select()                                  
          .apis(RequestHandlerSelectors.any())              
          .paths(PathSelectors.any())                          
          .build();                                           
    }

   @Override
   public void addResourceHandlers(ResourceHandlerRegistry registry) {
       registry.addResourceHandler("swagger-ui.html")
       .addResourceLocations("classpath:/META-INF/resources/");

       registry.addResourceHandler("/webjars/**")
       .addResourceLocations("classpath:/META-INF/resources/webjars/");
   }

}

try this
http://localhost:8080/spring-security-rest/api/swagger-ui.html
or
http://localhost:8080/spring-security-rest/swagger-ui.html

If that does not work, try to change the path in application.properties

Add this to application.properties:

server.servlet-path=/loop-service

and try the following urls:

http://localhost:8080/loop-service/swagger-ui.html (UI Docs)

http://localhost:8080/loop-service/v2/api-docs (JSON Docs)

Result :

Just use springdoc-openapi-ui instead.

The dependency:

<dependency>
     <groupId>org.springdoc</groupId>
     <artifactId>springdoc-openapi-ui</artifactId>
     <version>1.5.9</version>
</dependency>

And then for the UI just go to:

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

For the Json go to:

• http://localhost:8080/v3/api-docs

For yaml:

• http://localhost:8080/api-docs.yaml

That’s really all there is to it… No annotations / configuration needed. Cheers!

If you are using spring security, make sure you can reach these paths for it to work:

• /swagger-ui.html
• /swagger-ui/**
• /v3/api-docs/**

For more information:
https://www.baeldung.com/spring-rest-openapi-documentation