新手提问:关于"java.lang.NoClassDefFoundError:..."
用eclipse建立一个java工程,路径:D:\matrix\workspace\email,在该路径下:D:\matrix\workspace\email\com\matrix\send,有个发送电子邮件的类SimpleSender,其.java文件如下:
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package   com.matrix.send;

import   javax.mail.*;
import   javax.mail.internet.*;
import   java.util.*;

public   class   SimpleSender   {

/**
  *   @param   args
  */
public   static   void   main(String[]   args)  
{
//   TODO   Auto-generated   method   stub
try{

String   smtpServer=args[0];

String   to=args[1];

String   from=args[2];

String   subject=args[3];

String   body=args[4];

send(smtpServer,   to,   from,   subject,   body);
}
catch   (Exception   ex)
{
System.out.println( "Usage:   java   com.matrix.send.SimpleSender "
+ "   smtpServer   toAddress   fromAddress   subjectText   bodyText ");
}

System.exit(0);
}

public   static   void   send(String   smtpServer,   String   to,   String   from,   String   subject,   String   body)
{

try
{

Properties   props   =   System.getProperties();
//   --   Attaching   to   default   Session,   or   we   could   start   a   new   one   --
props.put( "mail.smtp.host ",   smtpServer);
Session   session   =   Session.getDefaultInstance(props,   null);
//   --   Create   a   new   message   --
Message   msg   =   new   MimeMessage(session);
//   --   Set   the   FROM   and   TO   fields   --
msg.setFrom(new   InternetAddress(from));
msg.setRecipients(Message.RecipientType.TO,
InternetAddress.parse(to,   false));

//   --   We   could   include   CC   recipients   too   --
//   if   (cc   !=   null)
//   msg.setRecipients(Message.RecipientType.CC
//   ,InternetAddress.parse(cc,   false));
//   --   Set   the   subject   and   body   text   --

msg.setSubject(subject);
msg.setText(body);

//   --   Set   some   other   header   information   --
msg.setHeader( "X-Mailer ",   "LOTONtechEmail ");
msg.setSentDate(new   Date());

//   --   Send   the   message   --
Transport.send(msg);
System.out.println( "Message   sent   OK. ");
}
catch   (Exception   ex)
{
System.out.println( "send   error! ");
ex.printStackTrace();
}
}
}
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在命令行:
D:\matrix\workspace\email\com\matrix\send> java   SimpleSender   smtp.tom.com   matrix2005   matrix2005   "test "   "test "

Exception   in   thread   "main "   java.lang.NoClassDefFoundError:   SimpleSender

请各位大虾指教!!!!

------解决方案--------------------