Spring Boot 2.7.3生产环境邮件发送异常排查求助

我维护的一个Spring Boot邮件通知应用近期出现随机停止工作的情况。原本使用自定义邮件库，现已切换为Spring官方邮件方案，并升级到Spring Boot 2.7.3版本，但在生产环境（Docker容器+OpenJDK11）中无法正常运行，本地IntelliJ环境下所有测试均正常。

pom.xml（仅邮件依赖） #

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

<dependency>
    <groupId>com.sun.activation</groupId>
    <artifactId>javax.activation</artifactId>
    <version>1.2.0</version>
</dependency>

<dependency>
    <groupId>com.sun.mail</groupId>
    <artifactId>jakarta.mail</artifactId>
</dependency>

application.properties配置 #

spring.mail.host=smtp.gmail.com
spring.mail.port=587
spring.mail.username=email
spring.mail.password=password
spring.mail.properties.mail.smtp.starttls.enable=true
spring.mail.properties.mail.smtp.starttls.required=true
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.connectiontimeout=5000
spring.mail.properties.mail.smtp.timeout=5000
spring.mail.properties.mail.smtp.writetimeout=5000

首次异常信息 #

INFO: Initializing Spring DispatcherServlet 'dispatcherServlet'
Exception in thread "Timer-10" java.lang.NoClassDefFoundError: jakarta/mail/Provider
        at java.base/java.lang.ClassLoader.defineClass1(Native Method)
        at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
        at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:174)
        at java.base/java.net.URLClassLoader.defineClass(URLClassLoader.java:555)
        at java.base/java.net.URLClassLoader$1.run(URLClassLoader.java:458)
        at java.base/java.net.URLClassLoader$1.run(URLClassLoader.java:452)
        at java.base/java.security.AccessController.doPrivileged(Native Method)
        at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:451)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:589)
        at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:151)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
        at java.base/java.lang.Class.forName0(Native Method)
        at java.base/java.lang.Class.forName(Class.java:398)
        at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.loadFromParent(TomcatEmbeddedWebappClassLoader.java:114)
        at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.doLoadClass(TomcatEmbeddedWebappClassLoader.java:87)
        at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.loadClass(TomcatEmbeddedWebappClassLoader.java:70)
        at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1220)
        at java.base/java.lang.Class.forName0(Native Method)
        at java.base/java.lang.Class.forName(Class.java:398)
        at java.base/java.util.ServiceLoader$LazyClassPathLookupIterator.nextProviderClass(ServiceLoader.java:1210)
        at java.base/java.util.ServiceLoader$LazyClassPathLookupIterator.hasNextService(ServiceLoader.java:1221)
        at java.base/java.util.ServiceLoader$LazyClassPathLookupIterator.hasNext(ServiceLoader.java:1265)
        at java.base/java.util.ServiceLoader$2.hasNext(ServiceLoader.java:1300)
        at java.base/java.util.ServiceLoader$3.hasNext(ServiceLoader.java:1385)
        at javax.mail.Session.loadProviders(Session.java:964)
        at javax.mail.Session.<init>(Session.java:254)
        at javax.mail.Session.getInstance(Session.java:298)
        at org.springframework.mail.javamail.JavaMailSenderImpl.getSession(JavaMailSenderImpl.java:163)
        at org.springframework.mail.javamail.JavaMailSenderImpl.createMimeMessage(JavaMailSenderImpl.java:341)
        at my.project.package.email.EmailService.sendEmail(EmailService.java:19)
        at my.project.package.email.EmailService$$FastClassBySpringCGLIB$$8248f369.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:793)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763)
        at net.bull.javamelody.MonitoringSpringInterceptor.invoke(MonitoringSpringInterceptor.java:76)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:708)
        at my.project.package.email.EmailService$$EnhancerBySpringCGLIB$$519bba90.sendEmail(<generated>)
        at my.project.package.cron.CheckTokenNuevo.sendEmail(CheckTokenNuevo.java:120)
        at my.project.package.cron.CheckTokenNuevo$1.run(CheckTokenNuevo.java:82)
        at java.base/java.util.TimerThread.mainLoop(Timer.java:556)
        at java.base/java.util.TimerThread.run(Timer.java:506)
Caused by: java.lang.ClassNotFoundException: jakarta.mail.Provider
        at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:476)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:589)
        at org.springframework.boot.loader.LaunchedURLClassLoader.loadClass(LaunchedURLClassLoader.java:151)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
        ... 44 more

添加额外依赖后的配置 #

尝试添加jakarta.mail-api依赖后，问题仍未解决，此时的pom.xml邮件依赖如下：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

<dependency>
    <groupId>com.sun.activation</groupId>
    <artifactId>javax.activation</artifactId>
    <version>1.2.0</version>
</dependency>

<dependency>
    <groupId>com.sun.mail</groupId>
    <artifactId>jakarta.mail</artifactId>
</dependency>

<dependency>
    <groupId>jakarta.mail</groupId>
    <artifactId>jakarta.mail-api</artifactId>
    <version>2.1.0</version>
</dependency>

新增依赖后的异常信息 #

java.util.ServiceConfigurationError: javax.mail.Provider: com.sun.mail.imap.IMAPProvider not a subtype
        at java.base/java.util.ServiceLoader.fail(ServiceLoader.java:589)
        at java.base/java.util.ServiceLoader$LazyClassPathLookupIterator.hasNextService(ServiceLoader.java:1237)
        at java.base/java.util.ServiceLoader$LazyClassPathLookupIterator.hasNext(ServiceLoader.java:1265)
        at java.base/java.util.ServiceLoader$2.hasNext(ServiceLoader.java:1300)
        at java.base/java.util.ServiceLoader$3.hasNext(ServiceLoader.java:1385)
        at javax.mail.Session.loadProviders(Session.java:964)
        at javax.mail.Session.<init>(Session.java:254)
        at javax.mail.Session.getInstance(Session.java:298)
        at org.springframework.mail.javamail.JavaMailSenderImpl.getSession(JavaMailSenderImpl.java:163)
        at org.springframework.mail.javamail.JavaMailSenderImpl.createMimeMessage(JavaMailSenderImpl.java:341)
        at my.project.package.email.EmailService.sendEmail(EmailService.java:22)
        at my.project.package.email.EmailService$$FastClassBySpringCGLIB$$8248f369.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:793)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763)
        at net.bull.javamelody.MonitoringSpringInterceptor.invoke(MonitoringSpringInterceptor.java:76)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:708)
        at my.project.package.email.EmailService$$EnhancerBySpringCGLIB$$42519d59.sendEmail(<generated>)
        at my.project.package.cron.CheckTokenNuevo.sendEmail(CheckTokenNuevo.java:120)
        at my.project.package.cron.CheckTokenNuevo$1.run(CheckTokenNuevo.java:82)
        at java.base/java.util.TimerThread.mainLoop(Timer.java:556)
        at java.base/java.util.TimerThread.run(Timer.java:506)

已尝试参考相关解决方案，但问题依旧。所有测试在本地IntelliJ环境正常，仅生产环境报错，寻求排查解决思路。

内容的提问来源于stack exchange，提问作者Alberto