How to override the transitive Swagger UI WebJar version in Springdoc 3.2.0?

[lcsalvess]

Hello everyone!

I’m using Springdoc OpenAPI 3.2.0 with Spring Boot 4.1.2 and Maven.

Springdoc 3.2.0 currently resolves the following transitive dependency:

• org.webjars:swagger-ui:5.34.0

I’d like to use a newer Swagger UI WebJar version (5.34.1) while keeping Springdoc 3.2.0.

I tried overriding the transitive dependency through Maven’s dependencyManagement:

org.webjars swagger-ui 5.34.1

Maven resolves the requested version correctly. However, after applying this override, Swagger UI resources start returning HTTP 404 in the application.

Removing the override restores Swagger UI functionality.

I also checked the Springdoc 3.2.0 POM and noticed that the Swagger UI version is centrally managed through the swagger-ui.version property.

My questions are:

1. Is overriding the Swagger UI WebJar version independently of Springdoc officially supported?
2. Is there any additional configuration required for webjars-locator-lite or Springdoc’s resource handling when changing the WebJar version?
3. Is there a recommended way to use a newer Swagger UI version without upgrading the entire Springdoc dependency?

I’d appreciate any guidance or recommendations from the maintainers or the community.

Thank you!

[stanleys12]

Overriding the WebJar in Maven is not enough. You also need to set springdoc.swagger-ui.version=5.34.1 in your application config (application.properties or application.yml).

Springdoc does not look up the WebJar version at runtime. It reads the version from its own config and builds the resource location from it, META-INF/resources/webjars/swagger-ui/<version>/:

springdoc-openapi/springdoc-openapi-starter-common/src/main/java/org/springdoc/ui/AbstractSwaggerConfigurer.java

Lines 62 to 63 in 3316c45

	String swaggerUiResourceLocation = WEBJARS_RESOURCE_LOCATION + SWAGGER_UI_WEBJAR_NAME + DEFAULT_PATH_SEPARATOR +
	swaggerUiConfigProperties.getVersion() + DEFAULT_PATH_SEPARATOR;

That version comes from SwaggerUiConfigProperties. If the property is empty, it falls back to springdoc.config.properties inside the springdoc jar:

springdoc-openapi/springdoc-openapi-starter-common/src/main/java/org/springdoc/core/properties/SwaggerUiConfigProperties.java

Lines 108 to 120 in 3316c45

	@Override
	public void afterPropertiesSet() {
	if (StringUtils.isEmpty(version)) {
	try {
	Resource resource = new ClassPathResource(DEFAULT_PATH_SEPARATOR + SPRINGDOC_CONFIG_PROPERTIES);
	Properties props = PropertiesLoaderUtils.loadProperties(resource);
	setVersion(props.getProperty(SPRINGDOC_SWAGGER_VERSION));
	}
	catch (IOException e) {
	throw new RuntimeException(e);
	}
	}
	}

That file is filled in at build time from the swagger-ui.version property in the springdoc pom, so in 3.2.0 it is hard-coded to 5.34.0:

springdoc-openapi/springdoc-openapi-starter-common/src/main/resources/springdoc.config.properties

Line 1 in 3316c45

springdoc.swagger-ui.version=@swagger-ui.version@

With your override, the classpath only has webjars/swagger-ui/5.34.1/, but springdoc still looks under 5.34.0/. That mismatch is the 404.

The fix is to set the property so both agree:

springdoc.swagger-ui.version=5.34.1

On your three questions:

1. Springdoc doesn't state that a different WebJar version is supported, but the springdoc.swagger-ui.version property exists for this. It is a normal property on a @ConfigurationProperties class with prefix springdoc.swagger-ui. A newer patch release like 5.34.1 should be fine. I haven't tested it with 5.34.1 itself.
2. No extra webjars-locator-lite configuration is needed. The SwaggerResourceResolver extends the lite resolver and also falls back to the version from that same property:
   

   springdoc-openapi/springdoc-openapi-starter-webmvc-ui/src/main/java/org/springdoc/webmvc/ui/SwaggerResourceResolver.java

   Lines 63 to 70 in 3316c45

   	@Nullable
   	@Override
   	protected String findWebJarResourcePath(String pathStr) {
   	String resourcePath = super.findWebJarResourcePath(pathStr);
   	if (resourcePath == null)
   	return findSwaggerResourcePath(pathStr, swaggerUiConfigProperties.getVersion());
   	return resourcePath;
   	}

3. Yes: your dependencyManagement override for org.webjars:swagger-ui plus the property above. Keep the two versions identical.

(I looked this up in the code with help from an AI assistant; the links are to the lines I checked.)

[lcsalvess]

Thank you very much for taking the time to answer my question and provide such a helpful explanation! I really appreciate your help. It was very useful in understanding the issue and finding the right solution. Thanks again! 😊