Java ch.qos.logback.core.util.DynamicClassLoadingException:未能实例化类型ch.qos.logback.classic.net.SMTPAppender

Java ch.qos.logback.core.util.DynamicClassLoadingException:未能实例化类型ch.qos.logback.classic.net.SMTPAppender,java,logging,smtp,logback,appender,Java,Logging,Smtp,Logback,Appender,我的spring boot应用程序中有以下logback.xml: <?xml version="1.0" encoding="UTF-8" ?> <configuration> <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> ... </appender> <timestamp key="datetime" d

我的spring boot应用程序中有以下
logback.xml

<?xml version="1.0" encoding="UTF-8" ?>
<configuration>

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
       ...
    </appender>

    <timestamp key="datetime" datePattern="yy-MM-dd-HH-mm-ss" />
    <appender name="FILE" class="ch.qos.logback.core.FileAppender">
        ...
    </appender>

    <appender name="EMAIL" class="ch.qos.logback.classic.net.SMTPAppender">
        <smtpHost>smtp.gmail.com</smtpHost>
        <smtpPort>587</smtpPort>
        <STARTTLS>true</STARTTLS>
        <username></username>
        <password></password>
        <to>admin@gmail.com</to>
        <from>dev@gmail.com</from>
        <subject>Error</subject>
        <layout class="ch.qos.logback.classic.html.HTMLLayout"/>
        <asynchronousSending>true</asynchronousSending>
        <encoder>
            <pattern>
                %d{dd.MM.yy HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
            </pattern>
        </encoder>
    </appender>

    <root level="INFO">
        <appender-ref ref="STDOUT" />
        <appender-ref ref="FILE" />
        <appender-ref ref="EMAIL" />
    </root>

</configuration>
我错了什么

compile ('javax.activation:activation:1.1.1')
compile ('javax.mail:mail:1.4.7')

依赖关系帮助了我

这将放在哪个文件中?build.gradle。如果您使用的是maven,那么可以将它们放在pom.xml文件中
compile ('javax.activation:activation:1.1.1')
compile ('javax.mail:mail:1.4.7')