NPE within AbstractRequestService

[vojkny]

Describe the bug

Within some of our services we are getting NPE in following code (SpringDoc 1.5) - while with some other everything seems to work correctly. With previous (Swagger2) solution we didn't experience this.

To Reproduce

It is hard to provide exact way to reproduce as it is happening without obvious reason: It happens that the schema variable becomes null which then fails on schema.setDefault(parameterInfo.getDefaultValue());

AbstractRequestService.java

               if (parameter.getSchema() == null && parameter.getContent() == null) {
			Schema<?> schema = parameterBuilder.calculateSchema(components, parameterInfo, null,
					jsonView);
			if (parameterInfo.getDefaultValue() != null)
				schema.setDefault(parameterInfo.getDefaultValue());
			parameter.setSchema(schema);
		}

Full stack trace:

java.lang.NullPointerException: null @/v3/api-docs java.lang.NullPointerException: null
	at org.springdoc.core.AbstractRequestService.buildParam(AbstractRequestService.java:466) ~[springdoc-openapi-common-1.5.0.jar:1.5.0]
	at org.springdoc.core.AbstractRequestService.buildParams(AbstractRequestService.java:418) ~[springdoc-openapi-common-1.5.0.jar:1.5.0]
	at org.springdoc.core.AbstractRequestService.build(AbstractRequestService.java:259) ~[springdoc-openapi-common-1.5.0.jar:1.5.0]
	at org.springdoc.api.AbstractOpenApiResource.calculatePath(AbstractOpenApiResource.java:376) ~[springdoc-openapi-common-1.5.0.jar:1.5.0]
	at org.springdoc.api.AbstractOpenApiResource.calculatePath(AbstractOpenApiResource.java:509) ~[springdoc-openapi-common-1.5.0.jar:1.5.0]
	at org.springdoc.webmvc.api.OpenApiResource.calculatePath(OpenApiResource.java:260) ~[springdoc-openapi-webmvc-core-1.5.0.jar:1.5.0]
	at org.springdoc.webmvc.api.OpenApiResource.getPaths(OpenApiResource.java:206) ~[springdoc-openapi-webmvc-core-1.5.0.jar:1.5.0]
	at org.springdoc.api.AbstractOpenApiResource.getOpenApi(AbstractOpenApiResource.java:272) ~[springdoc-openapi-common-1.5.0.jar:1.5.0]
	at org.springdoc.webmvc.api.OpenApiResource.openapiJson(OpenApiResource.java:181) ~[springdoc-openapi-webmvc-core-1.5.0.jar:1.5.0]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
	at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:197) ~[spring-web-5.3.1.jar:5.3.1]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:141) ~[spring-web-5.3.1.jar:5.3.1]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.3.1.jar:5.3.1]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:893) ~[spring-webmvc-5.3.1.jar:5.3.1]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:807) ~[spring-webmvc-5.3.1.jar:5.3.1]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.1.jar:5.3.1]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1061) [spring-webmvc-5.3.1.jar:5.3.1]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:961) [spring-webmvc-5.3.1.jar:5.3.1]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) [spring-webmvc-5.3.1.jar:5.3.1]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) [spring-webmvc-5.3.1.jar:5.3.1]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:626) [servlet-api.jar:4.0.FR]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) [spring-webmvc-5.3.1.jar:5.3.1]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:733) [servlet-api.jar:4.0.FR]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [catalina.jar:9.0.38]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [catalina.jar:9.0.38]
	at org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter.doFilterInternal(OpenEntityManagerInViewFilter.java:186) [spring-orm-5.3.1.jar:5.3.1]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.3.1.jar:5.3.1]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [catalina.jar:9.0.38]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [catalina.jar:9.0.38]
	at org.maite.web.AuthWebFilter.doFilter(AuthWebFilter.kt:30) [web-6-SNAPSHOT.jar:?]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [catalina.jar:9.0.38]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [catalina.jar:9.0.38]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) [tomcat-websocket.jar:9.0.38]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [catalina.jar:9.0.38]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [catalina.jar:9.0.38]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) [catalina.jar:9.0.38]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) [catalina.jar:9.0.38]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [catalina.jar:9.0.38]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:143) [catalina.jar:9.0.38]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [catalina.jar:9.0.38]
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:690) [catalina.jar:9.0.38]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) [catalina.jar:9.0.38]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [catalina.jar:9.0.38]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:374) [tomcat-coyote.jar:9.0.38]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-coyote.jar:9.0.38]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-coyote.jar:9.0.38]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1590) [tomcat-coyote.jar:9.0.38]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-coyote.jar:9.0.38]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-util.jar:9.0.38]

Expected behavior
This shouldn't fail.

[bnasslahsen]

@knyttl,

Unfortunately, you are not providing code to reproduce your issue...

I encourage you to find the reason you are getting this issue and share it, because this might hide a bad usage of the swagger-annotations .

A technical hot fix for this is now applied. Just to make the code execution safer. But this wouldn't resolve a potential bad usage of the swagger-annotations.

[vojkny]

But wouldn't it be better to handle this instead of getting NPE?

if (schema == null) throw IllegalStateExcpetion("Your schema on entity XXX is invalid, check...")

[bnasslahsen]

as we don't know your real reason. No.
And if you have any proposal, feel free to propose PR...