package io.formics.tourguide

import android.annotation.SuppressLint
import android.content.Intent
import android.net.Credentials
import android.net.Uri
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_feedback.*
import org.jetbrains.annotations.Async
import java.lang.Exception

import java.util.Properties;


import javax.activation.DataHandler;
import javax.activation.FileDataSource
import javax.mail.*
import javax.mail.internet.*


class FeedbackActivity : AppCompatActivity()  {
  
    val props = Properties()


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_feedback)

        props.put("mail.smtp.auth", "true");
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.port", "587");

        btnSendEmail.setOnClickListener {
            Thread {
                try {
                    sendEmail()
                    // Your implementation
                } catch (ex: Exception) {
                    ex.printStackTrace()
                }
            }.start()


        }
    }


    private fun sendEmail() {



        try {

            val session = Session.getInstance(props,
                object : javax.mail.Authenticator() {
                    //Authenticating the password
                    override fun getPasswordAuthentication(): javax.mail.PasswordAuthentication {
                        return PasswordAuthentication("abc@xyz.com", "password")
                    }
                })

            val message = MimeMessage(session);
            message.setFrom(InternetAddress("abc@xyz.com"));
            message.setRecipients(
                Message.RecipientType.TO,
                InternetAddress.parse(editCC.text.toString())
            )
            message.subject = editSubject.text.toString()
            message.setText(
                "Dear Mail Crawler,"
                        + "\n\n No spam to my email, please!"
            );

            //val messageBodyPart = MimeBodyPart();

            //val multipart = MimeMultipart();

            //val file = "path of file to be attached";

//            val fileName = "attachmentName"
           // val source = FileDataSource(file);
            //messageBodyPart.setDataHandler(DataHandler(source));
            //messageBodyPart.setFileName(fileName);
            //multipart.addBodyPart(messageBodyPart);

            //message.setContent(multipart);

            Transport.send(message);
            System.out.println("Done");



        } catch (e: MessagingException) {
            throw  RuntimeException(e);
        }

           }
}




 

无法连接到SMTP主机: Smtp.gmail.com，端口:465

在清单中添加这一行:

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

为了帮助那些获得网络主线程异常与SDK目标>9。这是使用droopie的代码上面，但将类似于任何工作。

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();

StrictMode.setThreadPolicy(policy); 

android.os.NetworkOnMainThreadException

您可以如下所示使用AsyncTask

public void onClickMail(View view) {
    new SendEmailAsyncTask().execute();
}

class SendEmailAsyncTask extends AsyncTask <Void, Void, Boolean> {
    Mail m = new Mail("from@gmail.com", "my password");

    public SendEmailAsyncTask() {
        if (BuildConfig.DEBUG) Log.v(SendEmailAsyncTask.class.getName(), "SendEmailAsyncTask()");
        String[] toArr = { "to mail@gmail.com"};
        m.setTo(toArr);
        m.setFrom("from mail@gmail.com");
        m.setSubject("Email from Android");
        m.setBody("body.");
    }

    @Override
    protected Boolean doInBackground(Void... params) {
        if (BuildConfig.DEBUG) Log.v(SendEmailAsyncTask.class.getName(), "doInBackground()");
        try {
            m.send();
            return true;
        } catch (AuthenticationFailedException e) {
            Log.e(SendEmailAsyncTask.class.getName(), "Bad account details");
            e.printStackTrace();
            return false;
        } catch (MessagingException e) {
            Log.e(SendEmailAsyncTask.class.getName(), m.getTo(null) + "failed");
            e.printStackTrace();
            return false;
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

用于发送带有附件的邮件..

public class SendAttachment{
                    public static void main(String [] args){ 
             //to address
                    String to="abc@abc.com";//change accordingly
                    //from address
                    final String user="efg@efg.com";//change accordingly
                    final String password="password";//change accordingly 
                     MailcapCommandMap mc = (MailcapCommandMap) CommandMap.getDefaultCommandMap();
                   mc.addMailcap("text/html;; x-java-content-handler=com.sun.mail.handlers.text_html");
                  mc.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml");
                  mc.addMailcap("text/plain;; x-java-content-handler=com.sun.mail.handlers.text_plain");
                  mc.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed");
                  mc.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822");
                  CommandMap.setDefaultCommandMap(mc); 
                  //1) get the session object   
                  Properties properties = System.getProperties();
                  properties.put("mail.smtp.port", "465"); 
                  properties.put("mail.smtp.host", "smtp.gmail.com");
                    properties.put("mail.smtp.socketFactory.port", "465");
                    properties.put("mail.smtp.socketFactory.class",
                            "javax.net.ssl.SSLSocketFactory");
                    properties.put("mail.smtp.auth", "true");
                    properties.put("mail.smtp.port", "465");

                  Session session = Session.getDefaultInstance(properties,
                   new javax.mail.Authenticator() {
                   protected PasswordAuthentication getPasswordAuthentication() {
                   return new PasswordAuthentication(user,password);
                   }
                  });

                  //2) compose message   
                  try{ 
                    MimeMessage message = new MimeMessage(session);
                    message.setFrom(new InternetAddress(user));
                    message.addRecipient(Message.RecipientType.TO,new InternetAddress(to));
                    message.setSubject("Hii"); 
                    //3) create MimeBodyPart object and set your message content    
                    BodyPart messageBodyPart1 = new MimeBodyPart();
                    messageBodyPart1.setText("How is This"); 
                    //4) create new MimeBodyPart object and set DataHandler object to this object    
                    MimeBodyPart messageBodyPart2 = new MimeBodyPart();
                //Location of file to be attached
                    String filename = Environment.getExternalStorageDirectory().getPath()+"/R2832.zip";//change accordingly
                    DataSource source = new FileDataSource(filename);
                    messageBodyPart2.setDataHandler(new DataHandler(source));
                    messageBodyPart2.setFileName("Hello"); 
                    //5) create Multipart object and add MimeBodyPart objects to this object    
                    Multipart multipart = new MimeMultipart();
                    multipart.addBodyPart(messageBodyPart1);
                    multipart.addBodyPart(messageBodyPart2); 
                    //6) set the multiplart object to the message object
                    message.setContent(multipart ); 
                    //7) send message 
                    Transport.send(message); 
                   System.out.println("MESSAGE SENT....");
                   }catch (MessagingException ex) {ex.printStackTrace();}
                  }
                }

这里有很多解决方案。然而，我认为我们必须改变GMail的配置，以允许从不太安全的设备访问。转到下面的链接并启用它。这对我很有用

https://myaccount.google.com/lesssecureapps?pli=1

那些正在获得ClassDefNotFoundError的人尝试移动这三个jar文件到你的项目的lib文件夹，它为我工作!!