[오류노트] - Swagger 3.0 설정시 발생하는 NullPointer 오류

오류 내용

org.springframework.context.ApplicationContextException: Failed to start bean'documentationPluginsBootstrapper'; nested exception is java.lang.NullPointerException

at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:181) ~[spring-context-5.3.13.jar:5.3.13]

at org.springframework.context.support.DefaultLifecycleProcessor.access 200(DefaultLifecycleProcessor.java:54) ~[spring-context-5.3.13.jar:5.3.13]

at org.springframework.context.support.DefaultLifecycleProcessorLifecycleGroup.start(DefaultLifecycleProcessor.java:356) ~[spring-context-5.3.13.jar:5.3.13]
at java.lang.Iterable.forEach(Iterable.java:75) ~[na:1.8.0_311]

at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:155) ~[spring-context-5.3.13.jar:5.3.13]

at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:123) ~[spring-context-5.3.13.jar:5.3.13]

at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:935) ~[spring-context-5.3.13.jar:5.3.13]

at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:586) ~[spring-context-5.3.13.jar:5.3.13]

at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.1.jar:2.6.1]

at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:730) ~[spring-boot-2.6.1.jar:2.6.1]

at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:412) ~[spring-boot-2.6.1.jar:2.6.1]

at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-2.6.1.jar:2.6.1]

at com.ej.batchtest.BatchTestApplication.main(BatchTestApplication.java:18) [main/:na]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_311]

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_311]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_311]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_311]

at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.6.1.jar:2.6.1]
Caused by: java.lang.NullPointerException: null

at springfox.documentation.spring.web.WebMvcPatternsRequestConditionWrapper.getPatterns(WebMvcPatternsRequestConditionWrapper.java:56) ~[springfox-spring-webmvc-3.0.0.jar:3.0.0]

at springfox.documentation.RequestHandler.sortedPaths(RequestHandler.java:113) ~[springfox-core-3.0.0.jar:3.0.0]

at springfox.documentation.spi.service.contexts.Orderings.lambda$byPatternsCondition$3(Orderings.java:89) ~[springfox-spi-3.0.0.jar:3.0.0]

환경

인텔리제이

jdk11
SpringBoot 2.6.1
gradle
Swagger 3.0.0
SwaggerUI 3.0.0

해결방법

1. 스웨거 설정한 class에 WebMvcConfiguationSupport 를 확장시킨다.

• 오류가 난 코드에는 extends를 따로 안 했었음

2. 새로운 경로를 잡아준다 (extends한 거 Override)

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