How to send mail programmatically in android using OAuth2.0 token

Question

I am developing an app in which I want to send mail programmatically using Gmail credentials, I know how to access device mail id and token using AccountManager. Please suggest me how to send mail using credentials with some code or tutorial. I am new to Android. Please help me thanks in advance..

Answer 1

After very hard work now i am able to login to Google using Oauth 2. now i am sharing here coz many questions are unanswered here. Below steps are require to login to Google.

1- Select a account from your device using

public static AccountManager accountManager;
accountManager = AccountManager.get(this);
Account[] accounts = accountManager.getAccountsByType("com.google");

2- Get a Token from selected account using

private void onAccountSelected(final Account account) {
accountManager.getAuthToken(account, AUTH_TOKEN_TYPE, null, this, new AccountManagerCallback<Bundle>() {
    public void run(AccountManagerFuture<Bundle> future) {
        try {
            String token = future.getResult().getString(AccountManager.KEY_AUTHTOKEN);
            useToken(account, token);
        } catch (OperationCanceledException e) {
            onAccessDenied();
        } catch (Exception e) {
            handleException(e);
        }
    }
}, null);

}

3- now Authenticate the Token using user account and Token. you will be able to login to google.

Note: After sometime token get unauthorized to login so you need to invalidate your token.

4- for re login you have to invalidate your token using

accountManager.invalidateAuthToken("com.google", token);

5- after invalidate you have to get a new token using

   String newToken = AccountManager.get(this).getAuthToken(new Account(account,        "com.google"),
                 AUTH_TOKEN_TYPE, true, null, null).getResult().getString(AccountManager.KEY_AUTHTOKEN);

6- in your AndroidManifest.xml add below uses permissions

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.GET_ACCOUNTS"/>
<uses-permission android:name="android.permission.USE_CREDENTIALS"/>

Thats all you require, now enjoy

Answer 2

 fist you download activation.jar,mail.jar,additionnal.jar and add to built to your project                                                       

And code r following
---------Create GMailSender.class
import javax.activation.DataHandler;   
import javax.activation.DataSource;   
import javax.mail.Message;   
import javax.mail.PasswordAuthentication;   
import javax.mail.Session;   
import javax.mail.Transport;   
import javax.mail.internet.InternetAddress;   
import javax.mail.internet.MimeMessage;   
import java.io.ByteArrayInputStream;   
import java.io.IOException;   
import java.io.InputStream;   
import java.io.OutputStream;   
import java.security.Security;   
import java.util.Properties;   

public class GMailSender extends javax.mail.Authenticator {   
    private String mailhost = "smtp.gmail.com";   
    private String user;   
    private String password;   
    private Session session;   

    static {   
        Security.addProvider(new JSSEProvider());   
    }  

    public GMailSender(String user, String password) {   
        this.user = user;   
        this.password = password;   

        Properties props = new Properties();   
        props.setProperty("mail.transport.protocol", "smtp");   
        props.setProperty("mail.host", mailhost);   
        props.put("mail.smtp.auth", "true");   
        props.put("mail.smtp.port", "465");   
        props.put("mail.smtp.socketFactory.port", "465");   
        props.put("mail.smtp.socketFactory.class",   
                "javax.net.ssl.SSLSocketFactory");   
        props.put("mail.smtp.socketFactory.fallback", "false");   
        props.setProperty("mail.smtp.quitwait", "false");   

        session = Session.getDefaultInstance(props, this);   
    }   

    protected PasswordAuthentication getPasswordAuthentication() {   
         return new PasswordAuthentication(user, password);   
    }   

    public synchronized void sendMail(String subject, String body, String sender, String recipients) throws Exception {   
        try{
        MimeMessage message = new MimeMessage(session);   
        DataHandler handler = new DataHandler(new ByteArrayDataSource(body.getBytes(), "text/plain"));   
        message.setSender(new InternetAddress(sender));   
        message.setSubject(subject);   
        message.setDataHandler(handler);   
        if (recipients.indexOf(',') > 0)   
            message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipients));   
        else  
            message.setRecipient(Message.RecipientType.TO, new InternetAddress(recipients));   
        Transport.send(message);   
        }catch(Exception e){
            e.printStackTrace();

        }
    }   

    public class ByteArrayDataSource implements DataSource {   
        private byte[] data;   
        private String type;   

        public ByteArrayDataSource(byte[] data, String type) {   
            super();   
            this.data = data;   
            this.type = type;   
        }   

        public ByteArrayDataSource(byte[] data) {   
            super();   
            this.data = data;   
        }   

        public void setType(String type) {   
            this.type = type;   
        }   

        public String getContentType() {   
            if (type == null)   
                return "application/octet-stream";   
            else  
                return type;   
        }   

        public InputStream getInputStream() throws IOException {   
            return new ByteArrayInputStream(data);   
        }   

        public String getName() {   
            return "ByteArrayDataSource";   
        }   

        public OutputStream getOutputStream() throws IOException {   
            throw new IOException("Not Supported");   
        }   
    }   
}  

2-Create JSSEProvider.class
import java.security.AccessController;
import java.security.Provider;

public final class JSSEProvider extends Provider {

    public JSSEProvider() {
        super("HarmonyJSSE", 1.0, "Harmony JSSE Provider");
        AccessController.doPrivileged(new java.security.PrivilegedAction<Void>() {
            public Void run() {
                put("SSLContext.TLS",
                        "org.apache.harmony.xnet.provider.jsse.SSLContextImpl");
                put("Alg.Alias.SSLContext.TLSv1", "TLS");
                put("KeyManagerFactory.X509",
                        "org.apache.harmony.xnet.provider.jsse.KeyManagerFactoryImpl");
                put("TrustManagerFactory.X509",
                        "org.apache.harmony.xnet.provider.jsse.TrustManagerFactoryImpl");
                return null;
            }
        });
    }
}

3-use This code in to your Activity button click etc..
try {   
                    GMailSender sender = new GMailSender("sender gmail ID", "password");
                    sender.sendMail("This is Subject",   
                            "This is Body",   
                            "receiverID",   
                            "receiverID");   
                } catch (Exception e) {   
                    Log.e("SendMail", e.getMessage(), e);   
                } 

Source: https://stackoverflow.com/a/2033124/865900 (credit where credit is due)