Why does springfox-swagger2 UI tell me “Unable to infer base url.”

Question

Why does springfox-swagger2 UI tell me Unable to infer base url. As far as I know, I am using a typical Swagger spring-boot configuration.

As you can

Answer 1

Add @EnableSwagger2 annotation in the main file of Springboot application

@SpringBootApplication
@EnableSwagger2
public class SampleApplication {

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

}

Answer 2

In my case I am deploying our springboot(2.1.2) with swagger2(2.9.2) application as war file in tomcat8.5 and getting the same error.

Later I was able to fix just by extending this class file AppConfig extends SpringBootServletInitializer

My complete AppConfig file

package org.mydomain

import java.net.URL;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.scheduling.annotation.EnableScheduling;

import springfox.documentation.swagger2.annotations.EnableSwagger2;

@SpringBootApplication(scanBasePackages = "org.mydomain")
@EntityScan({"org.mydomain.entity"})
@EnableJpaRepositories({"org.mydomain.repository"})
@EnableSwagger2
@EnableScheduling
public class AppConfig extends SpringBootServletInitializer {

  // We can optionally have spring boot way of starting main method
  public static void main(String[] args) {
     SpringApplication.run(AppConfig.class, args);
  }
}

This is the blog I referred how to deploy springboot application into tomcat

Note: I have not configured swagger docket just used the default implementation.

Answer 3

I had the same issue, but (maybe) I had a version missmatch in the pom.xml

My project version is:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.0.M5</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>

Then, It started to work when I added the following dependency:

  <dependency>
        <groupId>org.springframework.plugin</groupId>
        <artifactId>spring-plugin-core</artifactId>
        <version>1.2.0.RELEASE</version>
    </dependency>

Found at: https://github.com/springfox/springfox/issues/2932

Answer 4

For me the problem was that Spring Security was not allowing access to some resources needed by swagger-ui. The solution was to allow anonymous access to the following paths:

• /swagger-ui.html
• /webjars/**
• /v2/**
• /swagger-resources/**

In my case it is fine that these resources can be accessed without authentication.

Answer 5

Just Extend your main class with SpringBootServletInitalizer. It Will Work fine. Take reference as bellow.

public class TestApp extends SpringBootServletInitializer{

    public static void main(String[] args) {

       SpringApplication.run(TestApp.class, args);
   }
}

Answer 6

Check you Java Version first, it seems to not work with Version Java 11, try using Java 8 seems to be fine