Retrieve mail from Gmail account with pop3???

Question

I want to retrieve e-mail from my account on Gmail in my application, but I have a problem. I cant establishe a connection with pop3 server...
Do you have an example (full) in Java code for retrieving a mail from Gmail account.
I used the example from JavaMail Api 1,4 Specifications, but I have a problem with the parameters. (protocol null), and I dont know why...
Help me, please...

Answer 1

i hv retrived messages from gmail.but i m geting problem at the time ......
when i m reading mail which hava attachment.........
it is only showing attachment name...but not shoing the body part....
this is my programe........
plz any body help me its very urgent.........
give me a programe how to find the attachment name with body part........
//java msgshow -D -T pop3s -H pop.gmail.com -U user -P passwd
package MailServer;
import java.util.*;
import java.io.*;
import javax.mail.*;
import javax.mail.event.*;
import javax.mail.internet.*;
import javax.activation.*;
import java.util.Date ;
public class msgshow
static String protocol;
static String host = null;
static String user = null;
static String password = null;
static String mbox = null;
static String url = null;
static int port = -1;
static boolean verbose = false;
static boolean debug = false;
static boolean showStructure = false;
static boolean showMessage = false;
static boolean showAlert = false;
static boolean saveAttachments = false;
static int attnum = 1;
     static Message[] msgs = null;
     static String body = "";
     static String attachment = "";
     static String indentStr = " ";
static int level = 0;
static String from = "";
static String subject = "";
static Vector v ;
public Vector v1;
static Date date;
public Vector show()
          int msgnum = -1;
          int optind;
          InputStream msgStream = System.in;
          v = new Vector();
try
          // Get a Properties object
          Properties props = System.getProperties();
          // Get a Session object
          //debug = true;
          Session session = Session.getInstance(props, null);
          //session.setDebug(debug);
          // Get a Store object
          Store store = null;
          protocol = "pop3s";           
          store = session.getStore(protocol);
               host = "imap.gmail.com";
               user = "techzain";
               password = "zain1234";
               // Connect
          store.connect(host,port, user, password);
               //System.out.println ("connected");
          // Open the Folder
          Folder folder = store.getDefaultFolder();
               mbox = "INBOX";
          folder = folder.getFolder(mbox);
               //System.out.println ("opened inbox");
          // try to open read/write and if that fails try read-only
          try
                    folder.open(Folder.READ_WRITE);
          catch (MessagingException ex)
                    folder.open(Folder.READ_ONLY);
          // Attributes & Flags for all messages ..
               msgs = folder.getMessages();
               //System.out.println (msgs.length);
               for(int x=0;x<1;x++)
               try
                    //System.out.println ("inside for");
                    Address[] addList=msgs[x].getFrom();
                         if(addList.length>0)
                              from=((InternetAddress)addList[0]).getAddress();
                         subject=msgs[x].getSubject();
                         //body=(String)msgs[x].getContent();
                    date=msgs[x].getSentDate();
                    //body=(String)msgs[x].getContent();
                         //msgs[x].setFlag(Flags.Flag.SEEN,true);
                         if(msgs[x].isMimeType("multipart/*"))
                              boolean bbb=msgs[x].isSet(Flags.Flag.SEEN);
                         System.out.println (bbb);
                              Multipart multipart=(Multipart)msgs[x].getContent();
                              for(int i=0,n=multipart.getCount();i<n;i++)
                              {Part part=multipart.getBodyPart(i);
                                   if(i==0)
                                   body=part.getContent().toString();
                                   else
                                   //body=(String)msgs[x].getContent();
                                   attachment=part.getFileName();
                         else
                              boolean bbb1=msgs[x].isSet(Flags.Flag.SEEN);
                         System.out.println (bbb1);
                              body=(String)msgs[x].getContent();
                         //System.out.println ("ok");
                         if(attachment==null)
                              try
                                   v.addElement(x);
                                   v.addElement(from);
                                   v.addElement(date);
                                   v.addElement(subject);
                                   v.addElement(body);
                                   //System.out.println (v.size());
                              System.out.println("********* mail "+x+" ***********");
                              System.out.println("From: "+from);
                              System.out.println("Date: "+date);
                              System.out.println("Sub: "+subject);
                              System.out.println("body: "+body);
                              System.out.println("Attachment: No attachments......");
                              System.out.println ("*******************************\n\n");
                         catch (Exception ex)
                              ex.printStackTrace();
                         else
                              try{
                              v.addElement(x);
                              v.addElement(from);
                              v.addElement(date);
                              v.addElement(subject);
                              v.addElement(body);
                              v.addElement(attachment);
                              System.out.println("********* mail "+x+" ***********");
                              System.out.println("From: "+from);
                              System.out.println("Date: "+date);
                              System.out.println("Sub: "+subject);
                              System.out.println("body: "+body);
                              System.out.println("Attachment: "+attachment.toString());
                              System.out.println ("*******************************\n\n");
                         catch(Exception ex1)
                              ex1.printStackTrace();
                         //     System.out.println (v.size());
               catch (Exception ex)
                    ex.printStackTrace();
          catch(Exception e)
               e.printStackTrace();          
          System.out.println (v.size());
          return v;
     public static void main(String argv[])
     new msgshow().show();
          Flags flags = m.getFlags();
          StringBuffer sb = new StringBuffer();
          Flags.Flag[] sf = flags.getSystemFlags(); // get the system flags
          String s = "";
          for (int i = 0; i < sf.length; i++)
               if (sf[i] == Flags.Flag.SEEN)
                    s = "\\Seen";
                    System.out.println ("Seen Message");
*/