I have a Spring Boot application that uses WebSockets. I also want to expose Swagger UI using SpringDoc OpenAPI, but I'm running into an error.
When I try to access Swagger UI on /swagger-ui/index.html/, I get an error message that says "Can 'Upgrade' only to 'WebSocket'." It seems like the WebSockets endpoint is conflicting with the Swagger UI endpoint.
Here's my code:
@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {
@Override
public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
registry.addHandler(new MyWebSocketHandler(), "/*").setAllowedOrigins("*");
}
}
@Configuration
public class SpringDocConfig {
@Bean
public GroupedOpenApi publicApi() {
return GroupedOpenApi.builder()
.group("My API")
.pathsToMatch("/api/**")
.build();
}
}
<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.6.14</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>ws-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>ws-demo</name>
<description>ws-demo</description>
<properties>
<java.version>17</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-websocket</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>30.1-jre</version>
</dependency>
<dependency>
<groupId>org.springdoc</groupId>
<artifactId>springdoc-openapi-ui</artifactId>
<version>1.6.14</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
Is there a way to use WebSockets and SpringDoc OpenAPI together without running into this error and without having to change the websocket endpoint?
I've tried to set a custom URL for the Swagger UI in the Spring Doc configuration, using this property, but it didn't work as it just redirects to /swagger-ui/index.html:
springdoc.swagger-ui.path=
