Email

要用 Android 寄送郵件有幾種方法：

解決方法一，可以用 Intent 來開啟對應 App 來寄信。

解決方法二，使用 Java native 寄信，需要 SMTP 伺服器的支援。

需要建立幾個 class

GmailSender.java

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 com.provider.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){

        }
    }   

    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");   
        }   
    }   
}

JSSEProvider.java

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;
            }
        });
    }
}

最後 Activity 必需要用 AsyncTask

class SendMailTask extends AsyncTask<URL, Integer, Void>
{
	String	from;
	String	subject;
	String	content;

	public SendMailTask(String from, String subject, String content)
	{
		this.from = from;
		this.subject = subject;
		this.content = content;
	}

	@Override
	protected Void doInBackground(URL... urls)
	{
		try
		{
			Log.i(TAG, "Start sendmail");
			MailSender sender = new MailSender(APIs.MAIL_USER, APIs.MAIL_PASS);
			sender.sendMail(subject, from + ":\n" + content, from, APIs.MAIL_TO);
			Log.i(TAG, "End sendmail");
		}
		catch (Exception e)
		{
			Log.e("SendMail", e.getMessage(), e);
		}
		return null;
	}

	@Override
	protected void onPostExecute(Void result)
	{
	}

	@Override
	protected void onProgressUpdate(Integer... progress)
	{
	}
}

Email

References