問題描述：WebSocket在Controller中正常工作，但是在之后使用SpringBootTest進行單元測試的時候，突然提示WebSocket的相關錯誤。

錯誤提示：

Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'serverEndpointExporter' defined in class path resource [cn/edu/zzu/config/WebSocketConfiguration.class]: jakarta.websocket.server.ServerContainer not available

java.lang.IllegalStateException: Failed to load ApplicationContext for [WebMergedContextConfiguration@7686f701 testClass = cn.edu.zzu.ZzuServerApplicationTests, locations = [], classes = [cn.edu.zzu.ZzuServerApplication], contextInitializerClasses = [], activeProfiles = [], propertySourceDescriptors = [], propertySourceProperties = ["org.springframework.boot.test.context.SpringBootTestContextBootstrapper=true"], contextCustomizers = [org.springframework.boot.test.context.filter.ExcludeFilterContextCustomizer@173ed316, org.springframework.boot.test.json.DuplicateJsonObjectContextCustomizerFactory$DuplicateJsonObjectContextCustomizer@27406a17, org.springframework.boot.test.mock.mockito.MockitoContextCustomizer@0, org.springframework.boot.test.web.client.TestRestTemplateContextCustomizer@3a7442c7, org.springframework.boot.test.autoconfigure.actuate.observability.ObservabilityContextCustomizerFactory$DisableObservabilityContextCustomizer@1f, org.springframework.boot.test.autoconfigure.properties.PropertyMappingContextCustomizer@0, org.springframework.boot.test.autoconfigure.web.servlet.WebDriverContextCustomizer@5032714f, org.springframework.boot.test.context.SpringBootTestAnnotation@e578dfe0], resourceBasePath = "src/main/webapp", contextLoader = org.springframework.boot.test.context.SpringBootContextLoader, parent = null]at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:180)at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:130)at org.springframework.test.context.web.ServletTestExecutionListener.setUpRequestContextIfNecessary(ServletTestExecutionListener.java:191)at org.springframework.test.context.web.ServletTestExecutionListener.prepareTestInstance(ServletTestExecutionListener.java:130)at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:260)at org.springframework.test.context.junit.jupiter.SpringExtension.postProcessTestInstance(SpringExtension.java:163)at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625)at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)at java.base/java.util.stream.StreamSpliterators$WrappingSpliterator.forEachRemaining(StreamSpliterators.java:310)at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:735)at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:734)at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762)at java.base/java.util.Optional.orElseGet(Optional.java:364)at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'serverEndpointExporter' defined in class path resource [cn/edu/zzu/config/WebSocketConfiguration.class]: jakarta.websocket.server.ServerContainer not availableat org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1788)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:600)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522)at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:337)at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:335)at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:975)at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:962)at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:624)at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754)at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:456)at org.springframework.boot.SpringApplication.run(SpringApplication.java:335)at org.springframework.boot.test.context.SpringBootContextLoader.lambda$loadContext$3(SpringBootContextLoader.java:137)at org.springframework.util.function.ThrowingSupplier.get(ThrowingSupplier.java:58)at org.springframework.util.function.ThrowingSupplier.get(ThrowingSupplier.java:46)at org.springframework.boot.SpringApplication.withHook(SpringApplication.java:1463)at org.springframework.boot.test.context.SpringBootContextLoader$ContextLoaderHook.run(SpringBootContextLoader.java:553)at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:137)at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:108)at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:225)at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:152)... 17 more
Caused by: java.lang.IllegalStateException: jakarta.websocket.server.ServerContainer not availableat org.springframework.util.Assert.state(Assert.java:76)at org.springframework.web.socket.server.standard.ServerEndpointExporter.afterPropertiesSet(ServerEndpointExporter.java:107)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1835)at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1784)... 38 more

導致這個問題的原因：在測試環境中沒有WebSocket的環境，只需要添加一個標識即可。

// 修改后的注解，再次運行就不會提示WebSocket的錯誤
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
// @SpringBootTest  // 默認注解
@Slf4j
class ZzuServerApplicationTests {// 測試代碼
}