adding mail.jar ,activation.jar,additionnal.jar in android +Caused by: java.lang.NoClassDefFoundError:

Question

I am beginner to android.I am creating an app that has a feature to automatically send email to another person without user intervention.So i added mail.jar,additionnal.jar,activation.jar into my project.i am developing an app for android 2.2 or higher.I added the jar files as 1.right click project>import>browse and add the above jars to a folder named lib.my project doesn't have a lib/libs folder so icreated a folder lib. 2.right click project>properties>java build path>libraries>add jars.i added 3 jars to project and it appears in the project now.So the previous referencing errors when writing code were cleared. but when i run my app the app crashed everytime a call to Mail.java where i perform sending mail inside my app.Here is my complete code

Emailactivity.java

     class email extends AsyncTask<String, Void, Boolean>
{
    private Exception exception;
    int f=0;
    protected Boolean doInBackground(String...uname) 
    {
        try {
                f=0;
                Mail m = new Mail(fmailadd, password); 

              String[] toArr = {tmailadd, "anishubais@yahoo.co.in"}; 
              //String to="anishubais@gmail.com";
              m.setTo(toArr); 
              m.setFrom(fmailadd);            
              m.setSubject(type);
              m.setBody("This is an email sent by anish from android assistant."); 

              try 
              { 
                //m.addAttachment("/sdcard/filelocation"); 

                if(m.send())
                { 
                  //Toast.makeText(MainActivity.this, "Email was sent successfully.", Toast.LENGTH_LONG).show(); 
                  f=1;
                  Log.e("MailApp", "sucess");
                } else 
                { 
                  //Toast.makeText(MainActivity.this, "Email was not sent.", Toast.LENGTH_LONG).show(); 
                  f=0;
                  Log.e("MailApp", "failed");
                } 
              } 
              catch(Exception e) 
              { 
                //Toast.makeText(MailApp.this, "There was a problem sending the email.", Toast.LENGTH_LONG).show(); 
                Log.e("MailApp", "Could not send email", e); 
                f=0;
              } 
              if(f==1)
                  return true;
              else
                  return false;
        } catch (Exception e) {
            this.exception = e;
            return false;
        }
    }

}

call to this asynctask is inside Emailactivity as follows

    new email().execute("anish");

Mail.java:-Sending my mail here

     package androassist.mypack;

     import java.util.Date; 
     import java.util.Properties; 
     import javax.activation.CommandMap; 
     import javax.activation.DataHandler; 
     import javax.activation.DataSource; 
     import javax.activation.FileDataSource; 
     import javax.activation.MailcapCommandMap; 
     import javax.mail.BodyPart; 
     import javax.mail.Multipart; 
     import javax.mail.PasswordAuthentication; 
     import javax.mail.Session; 
     import javax.mail.Transport; 
     import javax.mail.internet.InternetAddress; 
      import javax.mail.internet.MimeBodyPart; 
      import javax.mail.internet.MimeMessage; 
      import javax.mail.internet.MimeMultipart; 

      public class Mail extends javax.mail.Authenticator { 
  private String _user; 
  private String _pass; 

  private String[] _to; 
  private String _from; 

  private String _port; 
  private String _sport; 

  private String _host; 

  private String _subject; 
  private String _body; 

  private boolean _auth; 

  private boolean _debuggable; 

  private Multipart _multipart; 


  public Mail() { 
    _host = "smtp.gmail.com"; // default smtp server 
    _port = "465"; // default smtp port 
    _sport = "465"; // default socketfactory port 

    _user = ""; // username 
    _pass = ""; // password 
    _from = ""; // email sent from 
    _subject = ""; // email subject 
    _body = ""; // email body 

    _debuggable = false; // debug mode on or off - default off 
    _auth = true; // smtp authentication - default on 

    _multipart = new MimeMultipart(); 

    // There is something wrong with MailCap, javamail can not find a handler for the multipart/mixed part, so this bit needs to be added. 
    MailcapCommandMap mc = (MailcapCommandMap) CommandMap.getDefaultCommandMap(); 
    mc.addMailcap("text/html;; x-java-content-handler=com.sun.mail.handlers.text_html"); 
    mc.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml"); 
    mc.addMailcap("text/plain;; x-java-content-handler=com.sun.mail.handlers.text_plain"); 
    mc.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed"); 
    mc.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822"); 
    CommandMap.setDefaultCommandMap(mc); 
  } 

  public Mail(String user, String pass) { 
    this(); 

    _user = user; 
    _pass = pass; 
  } 

  public boolean send() throws Exception { 
    Properties props = _setProperties(); 

    if(!_user.equals("") && !_pass.equals("") && _to.length > 0 && !_from.equals("") && !_subject.equals("") && !_body.equals("")) { 
      Session session = Session.getInstance(props, this); 

      MimeMessage msg = new MimeMessage(session); 

      msg.setFrom(new InternetAddress(_from)); 

      InternetAddress[] addressTo = new InternetAddress[_to.length]; 
      for (int i = 0; i < _to.length; i++) { 
        addressTo[i] = new InternetAddress(_to[i]); 
      } 
        msg.setRecipients(MimeMessage.RecipientType.TO, addressTo); 

      msg.setSubject(_subject); 
      msg.setSentDate(new Date()); 

      // setup message body 
      BodyPart messageBodyPart = new MimeBodyPart(); 
      messageBodyPart.setText(_body); 
      _multipart.addBodyPart(messageBodyPart); 

      // Put parts in message 
      msg.setContent(_multipart); 

      // send email 
      Transport.send(msg); 

      return true; 
    } else { 
      return false; 
    } 
  } 

  public void addAttachment(String filename) throws Exception { 
    BodyPart messageBodyPart = new MimeBodyPart(); 
    DataSource source = new FileDataSource(filename); 
    messageBodyPart.setDataHandler(new DataHandler(source)); 
    messageBodyPart.setFileName(filename); 

    _multipart.addBodyPart(messageBodyPart); 
  } 

  @Override 
  public PasswordAuthentication getPasswordAuthentication() { 
    return new PasswordAuthentication(_user, _pass); 
  } 

  private Properties _setProperties() { 
    Properties props = new Properties(); 

    props.put("mail.smtp.host", _host); 

    if(_debuggable) { 
      props.put("mail.debug", "true"); 
    } 

    if(_auth) { 
      props.put("mail.smtp.auth", "true"); 
    } 

    props.put("mail.smtp.port", _port); 
    props.put("mail.smtp.socketFactory.port", _sport); 
    props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory"); 
    props.put("mail.smtp.socketFactory.fallback", "false"); 

    return props; 
  } 

  // the getters and setters 
  public String getBody() 
  { 
    return _body; 
  } 

  public void setBody(String _body)
  { 
    this._body = _body; 
  } 
  public String getTo() 
  { 
        return _body; 
  } 

  public void setTo(String[] _to) 
  { 
        this._to = _to; 
  } 
  public String getFrom() 
  { 
        return _from; 
  } 

  public void setFrom(String _from) 
  { 
        this._from = _from; 
  } 
  public String getSubject() 
  { 
        return _subject; 
  } 

  public void setSubject(String _subject) 
  { 
        this._subject = _subject; 
  } 

} 

But when call to the mail.java performs it my app crashed,and forcefully closed

logcat error

    10-12 09:32:46.601: E/email(1779): anishubais13@gmail.com
     10-12 09:32:46.601: E/email(1779): anishubais@gmail.com
     10-12 09:32:46.601: W/dalvikvm(1779): Unable to resolve superclass of Landroassist/mypack/Mail; (186)
      10-12 09:32:46.601: W/dalvikvm(1779): Link of class 'Landroassist/mypack/Mail;' failed
    10-12 09:32:46.601: E/dalvikvm(1779): Could not find class  'androassist.mypack.Mail', referenced from method androassist.mypack.Email_acitivity$email.doInBackground
    10-12 09:32:46.601: W/dalvikvm(1779): VFY: unable to resolve new-instance 16 (Landroassist/mypack/Mail;) in Landroassist/mypack/Email_acitivity$email;
    10-12 09:32:46.601: D/dalvikvm(1779): VFY: replacing opcode 0x22 at 0x0005
    10-12 09:32:46.601: W/dalvikvm(1779): Unable to resolve superclass of Landroassist/mypack/Mail; (186)
    10-12 09:32:46.601: W/dalvikvm(1779): Link of class 'Landroassist/mypack/Mail;' failed
    10-12 09:32:46.601: D/dalvikvm(1779): DexOpt: unable to opt direct call 0x0039 at 0x0f in Landroassist/mypack/Email_acitivity$email;.doInBackground
    10-12 09:32:46.611: W/dalvikvm(1779): threadid=10: thread exiting with uncaught exception (group=0xb4dd3908)
    10-12 09:32:46.611: E/AndroidRuntime(1779): FATAL EXCEPTION: AsyncTask #1
    10-12 09:32:46.611: E/AndroidRuntime(1779): java.lang.RuntimeException: An error occured while executing doInBackground()
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at android.os.AsyncTask$3.done(AsyncTask.java:299)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at java.util.concurrent.FutureTask.run(FutureTask.java:239)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at java.lang.Thread.run(Thread.java:856)
     10-12 09:32:46.611: E/AndroidRuntime(1779): Caused by: java.lang.NoClassDefFoundError: androassist.mypack.Mail
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at androassist.mypack.Email_acitivity$email.doInBackground(Email_acitivity.java:267)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at androassist.mypack.Email_acitivity$email.doInBackground(Email_acitivity.java:1)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at android.os.AsyncTask$2.call(AsyncTask.java:287)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    at java.util.concurrent.FutureTask.run(FutureTask.java:234)
     10-12 09:32:46.611: E/AndroidRuntime(1779):    ... 3 more

I think it is the problem related to adding jars to my project.I tried the same code with android 4.2.it works without any error.I followed the above mentioned same procedure to add jars into project.But there i have already libs folder with my project.It is there when i created the project.So i added jars into libs.But i dont kow what to do here.I tried many solutions please help me.Please dont ignore my query?

Answer 1

Make sure the folder you added your jars to is libs and not lib. Your jar files should only be there, double-check that you have removed them from lib folder (actually, delete lib folder) and from your build path.