我如何在没有意图帮助的情况下发送电子邮件？

Question

我正在尝试实现一种无需@Vinayak Bevinakatti给出的用户交互即可发送电子邮件的解决方案。问题在于电子邮件永远不会发送/接收。

MailSenderActivity.java：

public class MailSenderActivity extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    final Button send = (Button) this.findViewById(R.id.send);
    send.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            try {   
                GMailSender sender = new GMailSender("username@gmail.com", "password");
                sender.sendMail("This is Subject",   
                        "This is Body",   
                        "user@gmail.com",   
                        "user@yahoo.com");   
            } catch (Exception e) {   
                Log.e("SendMail", e.getMessage(), e);   
            } 

        }
    });

}
}

GMailSender.java：

public class GMailSender extends javax.mail.Authenticator {
private String mailhost = "abhishek.roychoudhury69@gmail.com";
private String user;
private String password = "abhishekcena";
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){

    }
}

private static 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;
            }
        });
    }
}

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");
    }
}

}

我还在清单文件中输入了<uses-permission android:name="android.permission.INTERNET" />。而且我还将 mail.jar ， activation.jar 和 additional.jar 包含在我的Android项目中。