Java 运行时 jar 丢失

Question

我是java新手，

我正在尝试从我的 java 类发送电子邮件，我在 Windows 中尝试了代码，最初有一些问题。将 mail-1.4.jar 放入 C:\Program Files\Java\jdk1.8.0_91\jre\lib\ext 后，它运行正常。

我刚刚将其移至我的服务器(AWS)，将此 java 文件放入文件夹中并尝试运行此类。我将 mail-1.4.jar 放在路径 /opt/jdk1.7.0_79/jre/lib/ext

中

我的java类:

import java.io.IOException;
import java.net.URISyntaxException;
import java.util.Properties;

import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

public class Mail {

    public static void main(String[] args) throws IOException,
            URISyntaxException, AddressException, MessagingException {
        String BODY = "\n\n Regards Admin.";
        String SUBJECT = "SUBJECT";
        String TO = "fg@gddgh.com";

        final String FROM = "no-reply@dfh.com";
        final String SMTP_USERNAME = "SMTP_USERNAME";
        final String SMTP_PASSWORD = "SMTP_PASSWORD";
        final String HOST = "email-smtp.us-west-2.amazonaws.com";

        String message = "Email successfully sent";

        Properties props = System.getProperties();
        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.port", 25);
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.starttls.required", "true");

        Session session = Session.getDefaultInstance(props);

        MimeMessage msg = new MimeMessage(session);
            msg.setFrom(new InternetAddress(FROM));
            msg.setRecipient(Message.RecipientType.TO, new InternetAddress(TO));
            msg.setSubject(SUBJECT);
            msg.setContent(BODY, "text/plain");

            Transport transport = session.getTransport();
            try {
                transport.connect(HOST, SMTP_USERNAME, SMTP_PASSWORD);
                transport.sendMessage(msg, msg.getAllRecipients());
                System.out.println(message);
            } catch (Exception ex) {
                message = "Email not sent to the given ID";
                System.out.println(message);
            } finally {
                transport.close();
            }

    }
}

执行javac Mail.java命令时编译良好，但无法运行该类。我在执行 java Mail

时遇到以下异常

    Exception in thread "main" java.lang.NoClassDefFoundError: javax/mail/Address
            at java.lang.Class.getDeclaredMethods0(Native Method)
            at java.lang.Class.privateGetDeclaredMethods(Class.java:2625)
            at java.lang.Class.getMethod0(Class.java:2866)
            at java.lang.Class.getMethod(Class.java:1676)
            at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:494)
            at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:486)
    Caused by: java.lang.ClassNotFoundException: javax.mail.Address
            at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
            at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
            at java.security.AccessController.doPrivileged(Native Method)
            at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
            at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
            at java.lang.ClassLoader.loadClass(ClassLoader.java:358)

Answer 1

看来您没有将 jar 包含到 openJdk 中。

尝试将 jar 添加到您的 openJdk pathToOpenJdk/jre/lib/ext 文件夹中。它应该有效。

希望这有帮助。