오류 해결

swagger 3.0.0 에러 해결 및 실행 방법 (springboot 2.7.6, maven)

Nellie Kim 2023. 6. 17. 20:36
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몇시간을 고생시킨 애증의 스웨거, 버전 설정을 잘 해주니 해결되었다.

개발환경

Spring Boot 2.7.6
Maven
Java 11

 

기존코드

SwaggerConfig파일을 만들고, pom.xml에 아래와 같이 의존성을 추가했다.

<!-- Springfox Swagger -->
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger2</artifactId>
    <version>2.9.2</version>
</dependency>
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger-ui</artifactId>
    <version>2.9.2</version>
</dependency>

 

아래와 같은 오류가 났다. 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2023-06-17 19:09:05.660 ERROR 17096 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.context.ApplicationContextException: Failed to start bean 'documentationPluginsBootstrapper'; nested exception is java.lang.NullPointerException: Cannot invoke "org.springframework.web.servlet.mvc.condition.PatternsRequestCondition.toString()" because the return value of "springfox.documentation.spi.service.contexts.Orderings.patternsCondition(springfox.documentation.RequestHandler)" is null
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:181) ~[spring-context-5.3.24.jar:5.3.24]
	at org.springframework.context.support.DefaultLifecycleProcessor.access$200(DefaultLifecycleProcessor.java:54) ~[spring-context-5.3.24.jar:5.3.24]
	at org.springframework.context.support.DefaultLifecycleProcessor$LifecycleGroup.start(DefaultLifecycleProcessor.java:356) ~[spring-context-5.3.24.jar:5.3.24]
	at java.base/java.lang.Iterable.forEach(Iterable.java:75) ~[na:na]
	at org.springframework.context.support.DefaultLifecycleProcessor.startBeans(DefaultLifecycleProcessor.java:155) ~[spring-context-5.3.24.jar:5.3.24]
	at org.springframework.context.support.DefaultLifecycleProcessor.onRefresh(DefaultLifecycleProcessor.java:123) ~[spring-context-5.3.24.jar:5.3.24]
	at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:935) ~[spring-context-5.3.24.jar:5.3.24]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:586) ~[spring-context-5.3.24.jar:5.3.24]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:147) ~[spring-boot-2.7.6.jar:2.7.6]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:731) ~[spring-boot-2.7.6.jar:2.7.6]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:408) ~[spring-boot-2.7.6.jar:2.7.6]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) ~[spring-boot-2.7.6.jar:2.7.6]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) ~[spring-boot-2.7.6.jar:2.7.6]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) ~[spring-boot-2.7.6.jar:2.7.6]
	at com.winterfoodies.winterfoodies_project.WinterfoodiesProjectApplication.main(WinterfoodiesProjectApplication.java:10) ~[classes/:na]
Caused by: java.lang.NullPointerException: Cannot invoke "org.springframework.web.servlet.mvc.condition.PatternsRequestCondition.toString()" because the return value of "springfox.documentation.spi.service.contexts.Orderings.patternsCondition(springfox.documentation.RequestHandler)" is null
	at springfox.documentation.spi.service.contexts.Orderings$8.compare(Orderings.java:112) ~[springfox-spi-2.9.2.jar:null]
	at springfox.documentation.spi.service.contexts.Orderings$8.compare(Orderings.java:109) ~[springfox-spi-2.9.2.jar:null]
	at com.google.common.collect.ComparatorOrdering.compare(ComparatorOrdering.java:37) ~[guava-20.0.jar:na]
	at java.base/java.util.TimSort.countRunAndMakeAscending(TimSort.java:355) ~[na:na]
	at java.base/java.util.TimSort.sort(TimSort.java:220) ~[na:na]
	at java.base/java.util.Arrays.sort(Arrays.java:1233) ~[na:na]
	at com.google.common.collect.Ordering.sortedCopy(Ordering.java:855) ~[guava-20.0.jar:na]
	at springfox.documentation.spring.web.plugins.WebMvcRequestHandlerProvider.requestHandlers(WebMvcRequestHandlerProvider.java:57) ~[springfox-spring-web-2.9.2.jar:null]
	at springfox.documentation.spring.web.plugins.DocumentationPluginsBootstrapper$2.apply(DocumentationPluginsBootstrapper.java:138) ~[springfox-spring-web-2.9.2.jar:null]
	at springfox.documentation.spring.web.plugins.DocumentationPluginsBootstrapper$2.apply(DocumentationPluginsBootstrapper.java:135) ~[springfox-spring-web-2.9.2.jar:null]
	at com.google.common.collect.Iterators$7.transform(Iterators.java:750) ~[guava-20.0.jar:na]
	at com.google.common.collect.TransformedIterator.next(TransformedIterator.java:47) ~[guava-20.0.jar:na]
	at com.google.common.collect.TransformedIterator.next(TransformedIterator.java:47) ~[guava-20.0.jar:na]
	at com.google.common.collect.MultitransformedIterator.hasNext(MultitransformedIterator.java:52) ~[guava-20.0.jar:na]
	at com.google.common.collect.MultitransformedIterator.hasNext(MultitransformedIterator.java:50) ~[guava-20.0.jar:na]
	at com.google.common.collect.ImmutableList.copyOf(ImmutableList.java:249) ~[guava-20.0.jar:na]
	at com.google.common.collect.ImmutableList.copyOf(ImmutableList.java:209) ~[guava-20.0.jar:na]
	at com.google.common.collect.FluentIterable.toList(FluentIterable.java:614) ~[guava-20.0.jar:na]
	at springfox.documentation.spring.web.plugins.DocumentationPluginsBootstrapper.defaultContextBuilder(DocumentationPluginsBootstrapper.java:111) ~[springfox-spring-web-2.9.2.jar:null]
	at springfox.documentation.spring.web.plugins.DocumentationPluginsBootstrapper.buildContext(DocumentationPluginsBootstrapper.java:96) ~[springfox-spring-web-2.9.2.jar:null]
	at springfox.documentation.spring.web.plugins.DocumentationPluginsBootstrapper.start(DocumentationPluginsBootstrapper.java:167) ~[springfox-spring-web-2.9.2.jar:null]
	at org.springframework.context.support.DefaultLifecycleProcessor.doStart(DefaultLifecycleProcessor.java:178) ~[spring-context-5.3.24.jar:5.3.24]
	... 14 common frames omitted

 

문제는 swagger2 를 썼기 때문이다.

 

스프링부트 2.6 버전 이상을 쓰고 있으면  swagger2 를 쓰면 안된다! Swagger 3.X.X버전으로 코드를 작성해야 한다 .

 

아래와 같이 스웨거 설정을 해주어야 한다!

Spring boot 2.6버전 하위 - Swagger 2.X.X (swagger2)
Spring boot 2.6버전 상위 - Swagger 3.X.X

 

수정한 코드

SwaggerConfig 클래스 

@Configuration
public class SwaggerConfig {
    @Bean
    public Docket api() {
        return new Docket(DocumentationType.OAS_30)
                .apiInfo(apiInfo())
                .select()
                .apis(RequestHandlerSelectors.any())
                .paths(PathSelectors.any())
                .build();
    }


    public ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                .title("SpringBoot Practice Rest API Documentation")
                .description("springboot rest api practice.")
                .version("0.1")
                .build();
    }
}

 

application.properties 에 아래 코드 추가

# Swagger
spring.mvc.pathmatch.matching-strategy=ant_path_matcher

 

pom.xml 에 의존성 추가

<!-- Springfox Swagger -->
<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-boot-starter</artifactId>
    <version>3.0.0</version>
</dependency>

<dependency>
    <groupId>io.springfox</groupId>
    <artifactId>springfox-swagger-ui</artifactId>
    <version>3.0.0</version>
</dependency>

http://localhost:8080/swagger-ui/

위 url로 접속하면 아래와 같은 창이 뜬다!

swagger 화면

스웨거의 버전때문에 몇시간을 고생했다. 

스프링버전 2.6 이상을 쓰고 있다면 , 3.0.0버전으로 잘 수정해주어야 한다!!!