How can I access my gmail emails from a Java application?

I want to fetch the emails of my gmail account f开发者_开发知识库rom Java code. How can I go about doing this?

Here is the Refresh Working Code, that Displays the Email msgs in the console in a proper format along with the Attachments also being Downloaded....

import com.sun.mail.pop3.POP3Folder;
import com.sun.mail.pop3.POP3SSLStore;

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


public class MailfetchingPop3
{
    private Session session;
    private POP3SSLStore store;
    private String username;
    private String password;
    private POP3Folder folder;
    public static String numberOfFiles = null;
    public static int toCheck = 0;
    public static Writer output = null;
    URLName url;
    public static String receiving_attachments="C:\\download";

    public MailfetchingPop3()
    {
        session = null;
        store = null;
    }

    public void setUserPass(String username, String password)
    {
        this.username = username;
        this.password = password;
    }

    public void connect()
    throws Exception
    {
        String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
        Properties pop3Props = new Properties();
        pop3Props.setProperty("mail.pop3.socketFactory.class", SSL_FACTORY);
        pop3Props.setProperty("mail.pop3.socketFactory.fallback", "false");
        pop3Props.setProperty("mail.pop3.port", "995");
        pop3Props.setProperty("mail.pop3.socketFactory.port", "995");
        url = new URLName("pop3", "pop.gmail.com", 995, "", username, password);
        session = Session.getInstance(pop3Props, null);
        store = new POP3SSLStore(session, url);
        store.connect();
    }

    public void openFolder(String folderName)
    throws Exception
    {
        folder = (POP3Folder)store.getFolder(folderName);
        System.out.println((new StringBuilder("For test----")).append
(folder.getParent().getFullName()).toString());
        if(folder == null)
            throw new Exception("Invalid folder");
        try
        {
            folder.open(2);
            System.out.println((new StringBuilder("Folder name----")).append
(folder.getFullName()).toString());
        }
        catch(Exception ex)
        {
            System.out.println((new StringBuilder("Folder Opening Exception..")).append(ex).toString());
        }
    }

    public void closeFolder()
    throws Exception
    {
        folder.close(false);
    }

    public int getMessageCount()
    throws Exception
    {
        return folder.getMessageCount();
    }

    public int getNewMessageCount()
    throws Exception
    {
        return folder.getNewMessageCount();
    }

    public void disconnect()
    throws Exception
    {
        store.close();
    }

    public void printAllMessages()
    throws Exception
    {
        Message msgs[] = folder.getMessages();
        FetchProfile fp = new FetchProfile();
        folder.fetch(msgs, fp);
        for(int i = 0; i < msgs.length; i++){
            Message message = msgs[i];
            dumpEnvelope(msgs[i]);
        System.out.println("==============================");
    System.out.println("Email #" + (i + 1));
    System.out.println("Subject: " + message.getSubject());
    System.out.println("From: " + message.getFrom()[0]);
    System.out.println("Text: " + message.getContent().toString());
        }
    }



    public static int saveFile(File saveFile, Part part) throws Exception {

        BufferedOutputStream bos = new BufferedOutputStream( new
FileOutputStream(saveFile) );

        byte[] buff = new byte[2048];
        InputStream is = part.getInputStream();
        int ret = 0, count = 0;
        while( (ret = is.read(buff)) > 0 ){
            bos.write(buff, 0, ret);
            count += ret;
        }
        bos.close();
        is.close();
        return count;
    }

    private static void dumpEnvelope(Message m) throws Exception
    {
        String body="";
        String path="";
        int size=0;
        Object content = m.getContent();
        if(content instanceof String){
            body = (String)content;
        }
        else if(content instanceof Multipart)
        {
            Multipart mp = (Multipart)content;
            for (int j=0; j < mp.getCount(); j++)
            {
                Part part = mp.getBodyPart(j);
                String disposition = part.getDisposition();
                //System.out.println("test disposition---->>"+disposition);
                if (disposition == null) {
                    // Check if plain
                    MimeBodyPart mbp = (MimeBodyPart)part;
                    if (mbp.isMimeType("text/plain")) {
                        body += mbp.getContent().toString();
                    }
                    else if (mbp.isMimeType("TEXT/HTML")) {
                        body += mbp.getContent().toString();
                    }
                    else {
                        //unknown
                    }
                } else if ((disposition != null) &&
                        (disposition.equals(Part.ATTACHMENT) || disposition.equals
(Part.INLINE) || disposition.equals("ATTACHMENT") || disposition.equals
("INLINE")) )
                {
                    // Check if plain
                    MimeBodyPart mbp = (MimeBodyPart)part;
                    if (mbp.isMimeType("text/plain")) {
                        body += (String)mbp.getContent();
                    }
                    else if (mbp.isMimeType("TEXT/HTML")) {
                        body += mbp.getContent().toString();
                    }
                    else {
                        File savedir = new File(receiving_attachments);
                        savedir.mkdirs();
                        File savefile = new File(savedir+"\\"+part.getFileName());
                        path = savefile.getAbsolutePath();
                        size = saveFile( savefile, part);

                    }
                }
            }
        }

    }
    public static void main(String args[])
    {
        try
        {
            MailfetchingPop3 gmail = new MailfetchingPop3();
            gmail.setUserPass("your-gmail-username", "your-gmail-password");
            gmail.connect();
            gmail.openFolder("INBOX");
            gmail.printAllMessages();

        }
        catch(Exception e)
        {
            e.printStackTrace();
            System.exit(-1);
        }
    }



}

Another option: if you don't mind it being a Gmail-specific solution, note that Gmail also provides an RSS feed to your mailbox, which you can then access with normal XML processing APIs.

Gmail uses IMAP, which Javamail can use. Try to use that in an implementation, and if you get stuck, post some more specific questions here.

Here is the code which fetch mail along with it's attachments (if any) from a gmail account using POST OFFICE PROTOCOL (pop3) .

import com.sun.mail.pop3.POP3Folder;
import com.sun.mail.pop3.POP3SSLStore;

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


public class MailfetchingPop3
{
    private Session session;
    private POP3SSLStore store;
    private String username;
    private String password;
    private POP3Folder folder;
    public static String numberOfFiles = null;
    public static int toCheck = 0;
    public static Writer output = null;
    URLName url;
    public static String receiving_attachments="C:\\download";

    public MailfetchingPop3()
    {
        session = null;
        store = null;
    }

    public void setUserPass(String username, String password)
    {
        this.username = username;
        this.password = password;
    }

    public void connect()
    throws Exception
    {
        String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
        Properties pop3Props = new Properties();
        pop3Props.setProperty("mail.pop3.socketFactory.class", SSL_FACTORY);
        pop3Props.setProperty("mail.pop3.socketFactory.fallback", "false");
        pop3Props.setProperty("mail.pop3.port", "995");
        pop3Props.setProperty("mail.pop3.socketFactory.port", "995");
        url = new URLName("pop3", "pop.gmail.com", 995, "", username, password);
        session = Session.getInstance(pop3Props, null);
        store = new POP3SSLStore(session, url);
        store.connect();
    }

    public void openFolder(String folderName)
    throws Exception
    {
        folder = (POP3Folder)store.getFolder(folderName);
        System.out.println((new StringBuilder("For test----")).append(folder.getParent().getFullName()).toString());
        if(folder == null)
            throw new Exception("Invalid folder");
        try
        {
            folder.open(2);
            System.out.println((new StringBuilder("Folder name----")).append(folder.getFullName()).toString());
        }
        catch(Exception ex)
        {
            System.out.println((new StringBuilder("Folder Opening Exception..")).append(ex).toString());
        }
    }

    public void closeFolder()
    throws Exception
    {
        folder.close(false);
    }

    public int getMessageCount()
    throws Exception
    {
        return folder.getMessageCount();
    }

    public int getNewMessageCount()
    throws Exception
    {
        return folder.getNewMessageCount();
    }

    public void disconnect()
    throws Exception
    {
        store.close();
    }

    public void printAllMessages()
    throws Exception
    {
        Message msgs[] = folder.getMessages();
        FetchProfile fp = new FetchProfile();
        folder.fetch(msgs, fp);
        for(int i = 0; i < msgs.length; i++)
            dumpEnvelope(msgs[i]);

    }



    public static int saveFile(File saveFile, Part part) throws Exception {

        BufferedOutputStream bos = new BufferedOutputStream( new FileOutputStream(saveFile) );

        byte[] buff = new byte[2048];
        InputStream is = part.getInputStream();
        int ret = 0, count = 0;
        while( (ret = is.read(buff)) > 0 ){
            bos.write(buff, 0, ret);
            count += ret;
        }
        bos.close();
        is.close();
        return count;
    }

    private static void dumpEnvelope(Message m) throws Exception
    {
        String body="";
        String path="";
        int size=0;
        Object content = m.getContent();
        if(content instanceof String){
            body = (String)content;
        }
        else if(content instanceof Multipart)
        {
            Multipart mp = (Multipart)content;
            for (int j=0; j < mp.getCount(); j++)
            {
                Part part = mp.getBodyPart(j);
                String disposition = part.getDisposition();
                //System.out.println("test disposition---->>"+disposition);
                if (disposition == null) {
                    // Check if plain
                    MimeBodyPart mbp = (MimeBodyPart)part;
                    if (mbp.isMimeType("text/plain")) {
                        body += mbp.getContent().toString();
                    }
                    else if (mbp.isMimeType("TEXT/HTML")) {
                        body += mbp.getContent().toString();
                    }
                    else {
                        //unknown
                    }
                } else if ((disposition != null) &&
                        (disposition.equals(Part.ATTACHMENT) || disposition.equals(Part.INLINE) || disposition.equals("ATTACHMENT") || disposition.equals("INLINE")) )
                {
                    // Check if plain
                    MimeBodyPart mbp = (MimeBodyPart)part;
                    if (mbp.isMimeType("text/plain")) {
                        body += (String)mbp.getContent();
                    }
                    else if (mbp.isMimeType("TEXT/HTML")) {
                        body += mbp.getContent().toString();
                    }
                    else {
                        File savedir = new File(receiving_attachments);
                        savedir.mkdirs();
                        File savefile = new File(savedir+"\\"+part.getFileName());
                        path = savefile.getAbsolutePath();
                        size = saveFile( savefile, part);

                    }
                }
            }
        }

    }
    public static void main(String args[])
    {
        try
        {
            MailfetchingPop3 gmail = new MailfetchingPop3();
            gmail.setUserPass("your_gmail_Id", "your_gmail_mail_id_password");
            gmail.connect();
            gmail.openFolder("INBOX");
            gmail.printAllMessages();
        }
        catch(Exception e)
        {
            e.printStackTrace();
            System.exit(-1);
        }
    }



}

To run this java class you need to download javamail.jar and activation.jar