Spring Boot应用启动失败：嵌入式Tomcat初始化触发NPE

我的应用基于Spring Boot 2.5.12、Gradle 7.3.3构建，启动时无法启动嵌入式Tomcat，触发空指针异常（NPE），异常堆栈显示问题出在org.apache.tomcat.websocket.server.WsServerContainer的初始化阶段。已尝试Stack Overflow上的各类解决方案但均未成功，项目build.gradle已引入spring-boot-web等必要依赖，怀疑是Tomcat版本与其他库存在兼容性问题。

错误日志 #

2022-09-14 11:52:05.893 1179 [background-preinit] INFO  Version - HV000001: Hibernate Validator 6.2.3.Final
2022-09-14 11:52:05.972 1258 [main] INFO   - Starting app using Java 1.8.0_342 on 
2022-09-14 11:52:05.975 1261 [main] INFO   - The following 1 profile is active: "develop"
2022-09-14 11:52:07.126 2412 [main] INFO  RepositoryConfigurationDelegate - Bootstrapping Spring Data JPA repositories in DEFAULT mode.
2022-09-14 11:52:07.242 2528 [main] INFO  RepositoryConfigurationDelegate - Finished Spring Data repository scanning in 111 ms. Found 15 JPA repository interfaces.
2022-09-14 11:52:07.517 2803 [main] INFO  PostProcessorRegistrationDelegate$BeanPostProcessorChecker - Bean 'webSocketConfig' of type [cip.v32.services.service.investigation.modules.messaging.websocket.WebSocketConfig$$EnhancerBySpringCGLIB$$7dd4fc38] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying)
2022-09-14 11:52:07.773 3059 [main] INFO  TomcatWebServer - Tomcat initialized with port(s): 8081 (http)
2022-09-14 11:52:07.779 3065 [main] INFO  Http11NioProtocol - Initializing ProtocolHandler ["http-nio-8081"]
2022-09-14 11:52:07.780 3066 [main] INFO  StandardService - Starting service [Tomcat]
2022-09-14 11:52:07.780 3066 [main] INFO  StandardEngine - Starting Servlet engine: [Apache Tomcat/9.0.60]
2022-09-14 11:52:07.855 3141 [main] INFO  [/api/v1] - Initializing Spring embedded WebApplicationContext
2022-09-14 11:52:07.855 3141 [main] INFO  ServletWebServerApplicationContext - Root WebApplicationContext: initialization completed in 1839 ms
2022-09-14 11:52:07.998 3284 [main] ERROR ContainerBase - A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[/api/v1]]
    at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_342]
    at java.util.concurrent.FutureTask.get(FutureTask.java:192) 
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[/api/v1]]

Caused by: java.lang.NullPointerException
    at org.apache.tomcat.websocket.server.WsServerContainer.<init>(WsServerContainer.java:109) ~[tomcat-embed-websocket-9.0.60.jar:9.0.60]

build.gradle配置 #

plugins {
    id 'groovy'
    id 'org.springframework.boot' version '2.7.3'
    id 'io.spring.dependency-management' version '1.0.13.RELEASE'
    id 'java'
}

dependencies {
       // Third party dependencies
implementation 'org.springframework.boot:spring-boot-starter-actuator'
implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
implementation 'org.springframework.boot:spring-boot-starter-security'
implementation 'org.springframework.boot:spring-boot-starter-validation'
implementation 'org.springframework.boot:spring-boot-starter-web'
implementation 'org.springframework.retry:spring-retry'
implementation 'org.springframework.boot:spring-boot-starter-websocket'

// Third party dependencies
implementation 'com.auth0:java-jwt:3.8.3'                                               // Contains vulnerabilities
implementation 'com.codahale.metrics:metrics-core:3.0.2'
implementation 'com.google.code.findbugs:jsr305:3.0.0'
implementation 'com.google.code.gson:gson:2.8.5'                                        // Contains vulnerabilities
implementation 'com.googlecode.java-ipv6:java-ipv6:0.17'
implementation 'com.itextpdf:itextpdf:5.5.13.1'                                         // Contains vulnerabilities
implementation 'com.jayway.jsonpath:json-path:2.4.0'                                    // Contains vulnerabilities
implementation 'com.squareup.okhttp:okhttp:2.7.5'
implementation 'commons-beanutils:commons-beanutils:1.9.4'
implementation 'commons-net:commons-net:3.8.0'                                          // Contains vulnerabilities
implementation 'de.grundid.opendatalab:geojson-jackson:1.14'
implementation 'eu.bitwalker:UserAgentUtils:1.20'                                       // Contains vulnerabilities
implementation 'io.springfox:springfox-boot-starter:3.0.0'
implementation 'io.springfox:springfox-swagger-ui:3.0.0'
implementation 'javax.ws.rs:javax.ws.rs-api:2.1.1'                                      // Contains vulnerabilities
implementation 'org.apache.commons:commons-collections4:4.4'                            // Contains vulnerabilities
implementation 'org.apache.commons:commons-compress:1.21'
implementation 'org.apache.commons:commons-csv:1.9.0'
implementation 'org.apache.commons:commons-lang3:3.12.0'
implementation 'org.elasticsearch.client:elasticsearch-rest-high-level-client:7.12.1'   // Contains vulnerabilities
implementation 'org.jetbrains:annotations:13.0'
implementation 'org.openjdk.jmh:jmh-core:1.25'


annotationProcessor 'org.projectlombok:lombok:1.18.10'
annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
compileOnly 'org.projectlombok:lombok:1.18.10'


// Test dependencies
testImplementation 'com.h2database:h2'
testImplementation 'commons-io:commons-io:1.3.2'
testImplementation 'org.openjdk.jmh:jmh-generator-annprocess:1.25'
testImplementation 'org.spockframework:spock-core:2.0-groovy-3.0'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
testImplementation 'org.springframework.security:spring-security-test'
testImplementation 'org.testcontainers:junit-jupiter:1.15.0'
testImplementation 'org.testcontainers:postgresql:1.15.0'
testImplementation 'org.testcontainers:testcontainers:1.15.0'

testAnnotationProcessor 'org.projectlombok:lombok:1.18.10'
testCompileOnly 'org.projectlombok:lombok:1.18.10'
}

configurations.implementation {
    exclude group: 'ch.qos.logback', module: 'logback-classic'
    exclude group: 'ch.qos.logback', module: 'logback-core'
    exclude group: 'org.apache.logging.log4j', module: 'log4j-to-slf4j'
}

主类代码 #

@Data
@SpringBootApplication
@EnableRetry
@ConfigurationProperties(prefix = "spring.db")
public class CipMiddleware {
    

    public static void main(String[] args) {
        SpringApplication.run(CipMiddleware.class, args);
    }

}

内容的提问来源于stack exchange，提问作者Bartosz Bujnicki