如何修复ClassNotFoundException: com.sun.mail.util.MailLogger？

Question

我想要发送电子邮件，以下是我的代码：

public static void main(String[] args) {

    final String username = "[e-mail]";
    final String password = "password";

    Properties props = new Properties();
    props.put("mail.smtp.auth", "true");
    props.put("mail.smtp.starttls.enable", "true");
    props.put("mail.smtp.host", "smtp.gmail.com");
    props.put("mail.smtp.port", "587");

    Session session = Session.getInstance(props,
      new javax.mail.Authenticator() {
        protected PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication(username, password);
        }
      });

    try {

        Message message = new MimeMessage(session);
        message.setFrom(new InternetAddress("[e-mail]"));
        message.setRecipients(Message.RecipientType.TO,
            InternetAddress.parse("[e-mail]"));
        message.setSubject("Testing Subject");
        message.setText("Dear Mail Crawler,"
            + "\n\n No spam to my email, please!");

        Transport.send(message);

        System.out.println("Done");

    } catch (MessagingException e) {
        throw new RuntimeException(e);
    }
}

POM.xml

<dependency>
    <groupId>javax.mail</groupId>
    <artifactId>javax.mail-api</artifactId>
    <version>1.5.5</version>
</dependency>

但是出现了异常

Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/mail/util/MailLogger
at javax.mail.Session.initLogger(Session.java:230)
at javax.mail.Session.<init>(Session.java:214)
at javax.mail.Session.getInstance(Session.java:251)
at com.smart21.spring.utils.MailTest.main(MailTest.java:26)
Caused by: java.lang.ClassNotFoundException: com.sun.mail.util.MailLogger
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

- Gnik

---

尝试使用以下依赖项：<groupId>com.sun.mail</groupId> <artifactId>javax.mail</artifactId> <version>1.5.5</version>。我认为你应该同时使用这两个依赖项。问题在于java.mail-api没有实现。 - Sergei Sirik

是的，这在JavaMail项目页面上有描述（https://javaee.github.io/javamail/#Download_JavaMail_Release），最新版本是1.6.0。 - Bill Shannon

这个回答解决了你的问题吗？Java邮件的JUnit测试用例中出现java.lang.NoClassDefFoundError: com/sun/mail/util/MailLogger错误。 - Steve Chambers

Answer 1

尝试更改为：

<groupId>javax.mail</groupId>

致：

<groupId>com.sun.mail</groupId>

- Kohei TAMURA

---

请参考此答案进行解释。 - Steve Chambers

Answer 2

这是一个与Java邮件JUnit测试用例中的java.lang.NoClassDefFoundError: com/sun/mail/util/MailLogger问题重复的问题，以下是对我有效的答案：

        <dependency>
            <groupId>com.sun.mail</groupId>
            <artifactId>javax.mail</artifactId>
            <version>1.6.2</version>
        </dependency>

请查看https://dev59.com/PmQn5IYBdhLWcg3we3AE#16808343。

- Ashley Frieze

Answer 3

尝试从Oracle网站下载activation.jar和mail.jar，这将帮助您解决错误ClassNotFoundException: com.sun.mail.util.MailLogger。

- Yoshita Mahajan

Answer 4

解决方法是使用正确的依赖项。对于Gradle：

// https://mvnrepository.com/artifact/javax.mail/mail
compile group: 'javax.mail', name: 'mail', version: '1.5.0-b01'

- Jackkobec