Question

I wrote a small Java command line program to test sending emails from a remote server. I’m getting the dreaded “NoClassDefFoundError” and I can’t figure out why.

The server is running:

• SunOS 5.10 Generic January 2005
• Java 1.5.0_30-b03 ( Sun, standard )

My java program is called

SendEmailACME

The error message is

Exception in thread "main" java.lang.NoClassDefFoundError: javax/activation/DataSource

The complete output from the run of the program is:

bash-3.00$ javac SendEmailACME.java
bash-3.00$ java SendEmailACME
SendEmailACME: Classpath: .:/users/steve/TestProgramsLib/mail.jar:users/steve/TestProgramsLib/activation.jar
DEBUG: setDebug: JavaMail version 1.4.4
Exception in thread "main" java.lang.NoClassDefFoundError: javax/activation/DataSource
        at SendEmailACME.main(SendEmailACME.java:47)
bash-3.00$ 

I ran

java -verbose SendEmailACME

The ouput was too long for stackoverflow. All it included was the regular output, plus a bunch of messages about java loading all of its regular libraries, the libraries from mail.jar, but I didn’t see any from javax.activation.*

Output from “$ echo $CLASSPATH” is:

bash-3.00$ echo $CLASSPATH
.:/users/steve/TestProgramsLib/mail.jar:users/steve/TestProgramsLib/activation.jar
bash-3.00$

My home directory is

/users/steve

It contains these two directories

1. TestPrograms
2. TestProgramsLib

The first has my program SendEmailACME.java, SendEmailACME.class/
The second has the following jars in it:

bash-3.00$ ls -l
total 1102
-rw-r--r--   1 steve  acme      55932 Apr 19  2006 activation.jar
-rw-r--r--   1 steve  acme     494975 Jan 14  2011 mail.jar
bash-3.00$

This is the source code of my command line program SendEmailACME:

import javax.mail.*;
import javax.mail.internet.*;
import javax.mail.Authenticator;
import javax.mail.PasswordAuthentication;

import java.util.Properties;

public class SendEmailACME {


    public static void main(String[] args) throws Exception{


        String smtpServer  = "msg.abc.acme.com";
        int port           = 25;        
        String userid      = "acme.staffdirectory"; 
        String password    = "password";  
        String contentType = "text/html";

        String subject     = "test: Send An Email, From A Java Client Using msg.abc.acme.com";
        String from        = "[e-mail]";
        String to          = "[e-mail],[e-mail],[e-mail],[e-mail]";
        String body        = "<h1>Test. An Email, From A Java Client Using msg.abc.acme.com.</hi>";

        System.out.println("SendEmailACME: Classpath: " + System.getProperty("java.class.path"));

        Properties props   = new Properties();
        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.starttls.enable","true");
        props.put("mail.smtp.host", smtpServer);

        Session mailSession = Session.getInstance(props);

        // Get runtime more runtime output when attempting to send an email
        mailSession.setDebug(true);

        MimeMessage message = new MimeMessage(mailSession);
        message.setFrom(new InternetAddress(from));
        message.setRecipients(Message.RecipientType.TO, to);
        message.setSubject(subject);
        message.setContent(body,contentType);

        Transport transport = mailSession.getTransport();
        transport.connect(smtpServer, port, userid, password);
        transport.sendMessage(message,message.getRecipients(Message.RecipientType.TO));
        transport.close();
    }// end function main()

}// end class SendEmailACME

Here is the output from running a command to see what is inside activation.jar:

bash-3.00$ jar -tf activation.jar
META-INF/MANIFEST.MF
META-INF/SUN_MICR.SF
META-INF/SUN_MICR.RSA
META-INF/
META-INF/mailcap.default
META-INF/mimetypes.default
javax/
javax/activation/
javax/activation/ActivationDataFlavor.class
javax/activation/MimeType.class
javax/activation/MimeTypeParameterList.class
javax/activation/MimeTypeParseException.class
javax/activation/CommandInfo.class
javax/activation/DataHandler$1.class
javax/activation/DataHandler.class
javax/activation/DataSource.class
javax/activation/CommandMap.class
javax/activation/DataContentHandler.class
javax/activation/DataContentHandlerFactory.class
javax/activation/CommandObject.class
javax/activation/DataHandlerDataSource.class
javax/activation/DataSourceDataContentHandler.class
javax/activation/ObjectDataContentHandler.class
javax/activation/FileDataSource.class
javax/activation/FileTypeMap.class
javax/activation/MailcapCommandMap.class
javax/activation/MimetypesFileTypeMap.class
javax/activation/SecuritySupport$1.class
javax/activation/SecuritySupport$2.class
javax/activation/SecuritySupport$3.class
javax/activation/SecuritySupport$4.class
javax/activation/SecuritySupport$5.class
javax/activation/SecuritySupport.class
javax/activation/URLDataSource.class
javax/activation/UnsupportedDataTypeException.class
com/
com/sun/
com/sun/activation/
com/sun/activation/registries/
com/sun/activation/registries/MailcapFile.class
com/sun/activation/registries/MailcapParseException.class
com/sun/activation/registries/MimeTypeFile.class
com/sun/activation/registries/MimeTypeEntry.class
com/sun/activation/registries/LineTokenizer.class
com/sun/activation/registries/LogSupport.class
com/sun/activation/registries/MailcapTokenizer.class
com/sun/activation/viewers/
com/sun/activation/viewers/ImageViewer.class
com/sun/activation/viewers/ImageViewerCanvas.class
com/sun/activation/viewers/TextEditor.class
com/sun/activation/viewers/TextViewer.class
bash-3.00$

Everything compiles fine, but it can’t seem to find javax.activation.DataSource despite activation.jar being in the classpath

I do not have access to the jdk_home/jre/lib/ext directory.

I have been attempting to execute SendEmailACME from my directory
/users/steve/TestPrograms

Thanks in advance for any help

Steve

Answer 1

bash-3.00$ echo $CLASSPATH
.:/users/steve/TestProgramsLib/mail.jar:users/steve/TestProgramsLib/activation.jar

You appear to be missing a / between mail.jar: and users/steve. This means java is looking in the wrong place for activation.jar (in ./users rather than /users).