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JavaMail API收到NullpointerException

[英]JavaMail API getting NullpointerException

 原文  2014-08-28 13:57:44  5   1    java/ android/ email

問題描述

我正在嘗試不使用電子郵件客戶端發送電子郵件。 因此，我嘗試了一些教程中給出的代碼。 但是總是，當我嘗試發送電子郵件時，發送失敗，在transport.connect()方法上顯示NullPointerException 。

我的密碼 

package com.example.app;


import java.io.UnsupportedEncodingException;
import java.util.List;
import java.util.Properties;

import javax.mail.AuthenticationFailedException;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

import android.util.Log;

public class GMail {

    final String emailPort = "587";// gmail's smtp port
    final String smtpAuth = "true";
    final String starttls = "true";
    final String emailHost = "smtp.gmail.com";
    // final String fromUser = "****";
    // final String fromUserEmailPassword = "****";

    String fromEmail;
    String fromPassword;
    List<String> toEmailList;
    String emailSubject;
    String emailBody;

    Properties emailProperties;
    Session mailSession;
    MimeMessage emailMessage;

    public GMail() {

    }

    public GMail(String fromEmail, String fromPassword,
            List<String> toEmailList, String emailSubject, String emailBody) {
        this.fromEmail = fromEmail;
        this.fromPassword = fromPassword;
        this.toEmailList = toEmailList;
        this.emailSubject = emailSubject;
        this.emailBody = emailBody;

        emailProperties = System.getProperties();
        emailProperties.put("mail.smtp.port", emailPort);
        emailProperties.put("mail.smtp.auth", smtpAuth);
        emailProperties.put("mail.smtp.starttls.enable", starttls);
        Log.i("GMail", "Mail server properties set.");
    }

    public MimeMessage createEmailMessage() throws AddressException,
            MessagingException, UnsupportedEncodingException {

        mailSession = Session.getInstance(emailProperties, null);
        emailMessage = new MimeMessage(mailSession);

        emailMessage.setFrom(new InternetAddress(fromEmail, fromEmail));
        for (String toEmail : toEmailList) {
            Log.i("GMail","toEmail: "+toEmail);
            emailMessage.addRecipient(Message.RecipientType.TO,
                    new InternetAddress(toEmail));
        }

        emailMessage.setSubject(emailSubject);
        emailMessage.setContent(emailBody, "text/html");// for a html email
//      emailMessage.setText(emailBody);// for a text email
        Log.i("GMail", "Email Message created.");
        return emailMessage;
    }

    public void sendEmail() throws AddressException, MessagingException, AuthenticationFailedException {
        try{
            Transport transport = mailSession.getTransport("smtp");
            Log.i("GMail", "Transport created");
            transport.connect(emailHost, fromEmail, fromPassword);
            Log.i("GMail","allrecipients: "+emailMessage.getAllRecipients());
            transport.sendMessage(emailMessage, emailMessage.getAllRecipients());
            transport.close();
            Log.i("GMail", "Email sent successfully.");
        }
        catch(Exception e){
            Log.i("GMail", "Exception " + e.getMessage());
        }
    }

}

使用AsyncTask發送郵件： 

package com.example.app;


import java.util.List;

import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.util.Log;

public class SendMailTask extends AsyncTask {

    private ProgressDialog statusDialog;
    private Activity sendMailActivity;

    public SendMailTask(Activity activity) {
        sendMailActivity = activity;

    }

    protected void onPreExecute() {
        statusDialog = new ProgressDialog(sendMailActivity);
        statusDialog.setMessage("Getting ready...");
        statusDialog.setIndeterminate(false);
        statusDialog.setCancelable(false);
        statusDialog.show();
    }

    @Override
    protected Object doInBackground(Object... args) {
        try {
            Log.i("SendMailTask", "About to instantiate GMail...");
            publishProgress("Processing input....");
            GMail androidEmail = new GMail(args[0].toString(),
                    args[1].toString(), (List) args[2], args[3].toString(),
                    args[4].toString());
            publishProgress("Preparing mail message....");
            androidEmail.createEmailMessage();
            publishProgress("Sending email....");
            androidEmail.sendEmail();
            publishProgress("Email Sent.");
            Log.i("SendMailTask", "Mail Sent.");
        } catch (Exception e) {
            publishProgress(e.getMessage());
            Log.e("SendMailTask", e.getMessage(), e);
        }
        return null;
    }

    @Override
    public void onProgressUpdate(Object... values) {
        statusDialog.setMessage(values[0].toString());

    }

    @Override
    public void onPostExecute(Object result) {
        statusDialog.dismiss();
    }

}

在此活動中，我調用sendMail() ： 

package com.example.app;

import java.util.Arrays;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.RadioGroup;

public class Attendance extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.attendance);
    }

    public void clickButSubmit(View view){
        String to="****@freenet.de";
        String from="****";
        String pwd="****";
        String subject="test";
        String message="bla blub";
        List<String> toEmailList=Arrays.asList(to.split("\\s*,\\s*"));
        Log.i("Attendance", "toEmailList" + toEmailList);

        new SendMailTask(Attendance.this).execute(from,pwd,toEmailList,subject,message);
    }

    public void clickButClear(View view){
        RadioGroup rg = (RadioGroup) findViewById(R.id.button_group_attendance);
        rg.clearCheck();
        rg=(RadioGroup) findViewById(R.id.button_group_stint);
        rg.clearCheck();
        rg=(RadioGroup) findViewById(R.id.button_group_weekend);
        rg.clearCheck();        
    }
}

它不適用於用戶名**或* @ googlemail.com。

身份驗證一定存在問題，因為transport.connect()方法會引發異常。

這是日志： 

08-28 09:42:59.456: I/GMail(4304): Email Message created.
08-28 09:42:59.846: I/GMail(4304): Transport created
08-28 09:43:02.846: I/GMail(4304): Exception null
08-28 09:43:02.846: I/SendMailTask(4304): Mail Sent.

忽略“已發送郵件”日志，因為我只捕獲異常而沒有任何干預。

編輯：異常處理程序中的e.printStackTrace（）給出： 

08-28 10:06:04.317: I/GMail(5439): Exception null
08-28 10:06:04.317: W/System.err(5439): javax.mail.AuthenticationFailedException
08-28 10:06:04.317: W/System.err(5439):     at javax.mail.Service.connect(Service.java:319)
08-28 10:06:04.317: W/System.err(5439):     at com.example.app.GMail.sendEmail(GMail.java:82)
08-28 10:06:04.367: W/System.err(5439):     at com.example.app.SendMailTask.doInBackground(SendMailTask.java:40)
08-28 10:06:04.427: W/System.err(5439):     at android.os.AsyncTask$2.call(AsyncTask.java:288)
08-28 10:06:04.437: W/System.err(5439):     at java.util.concurrent.FutureTask.run(FutureTask.java:237)
08-28 10:06:04.447: W/System.err(5439):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
08-28 10:06:04.447: W/System.err(5439):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
08-28 10:06:04.447: W/System.err(5439):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
08-28 10:06:04.497: W/System.err(5439):     at java.lang.Thread.run(Thread.java:841)

因此，我建議在transport.connect()-method

編輯2：使用mailSession.setDebug（true）： 

08-28 11:19:34.664: I/GMail(9492): Email Message created.
08-28 11:19:34.674: I/System.out(9492): DEBUG: getProvider() returning javax.mail.Provider[TRANSPORT,smtp,com.sun.mail.smtp.SMTPTransport,Sun Microsystems, Inc.,1.4.1]
08-28 11:19:34.684: I/GMail(9492): Transport created
08-28 11:19:34.684: I/GMail(9492): host smtp.gmail.com
08-28 11:19:34.684: I/GMail(9492): user name xxxx
08-28 11:19:34.734: I/GMail(9492): pwd xxxx
08-28 11:19:34.744: I/System.out(9492): DEBUG SMTP: useEhlo true, useAuth true
08-28 11:19:34.744: I/System.out(9492): DEBUG SMTP: trying to connect to host "smtp.gmail.com", port 587, isSSL false
08-28 11:19:35.824: I/System.out(9492): 220 mx.google.com ESMTP wr10sm10759961wjc.10 - gsmtp
08-28 11:19:35.894: I/System.out(9492): DEBUG SMTP: connected to host "smtp.gmail.com", port: 587
08-28 11:19:35.964: I/System.out(9492): EHLO localhost
08-28 11:19:36.014: I/System.out(9492): 250-mx.google.com at your service, [158.181.68.197]
08-28 11:19:36.024: I/System.out(9492): 250-SIZE 35882577
08-28 11:19:36.034: I/System.out(9492): 250-8BITMIME
08-28 11:19:36.034: I/System.out(9492): 250-STARTTLS
08-28 11:19:36.034: I/System.out(9492): 250-ENHANCEDSTATUSCODES
08-28 11:19:36.034: I/System.out(9492): 250-PIPELINING
08-28 11:19:36.034: I/System.out(9492): 250-CHUNKING
08-28 11:19:36.084: I/System.out(9492): 250 SMTPUTF8
08-28 11:19:36.094: I/System.out(9492): DEBUG SMTP: Found extension "SIZE", arg "35882577"
08-28 11:19:36.094: I/System.out(9492): DEBUG SMTP: Found extension "8BITMIME", arg ""
08-28 11:19:36.104: I/System.out(9492): DEBUG SMTP: Found extension "STARTTLS", arg ""
08-28 11:19:36.154: I/System.out(9492): DEBUG SMTP: Found extension "ENHANCEDSTATUSCODES", arg ""
08-28 11:19:36.164: I/System.out(9492): DEBUG SMTP: Found extension "PIPELINING", arg ""
08-28 11:19:36.164: I/System.out(9492): DEBUG SMTP: Found extension "CHUNKING", arg ""
08-28 11:19:36.164: I/System.out(9492): DEBUG SMTP: Found extension "SMTPUTF8", arg ""
08-28 11:19:36.214: I/System.out(9492): STARTTLS
08-28 11:19:36.284: I/System.out(9492): 220 2.0.0 Ready to start TLS
08-28 11:19:38.214: I/System.out(9492): EHLO localhost
08-28 11:19:38.264: I/System.out(9492): 250-mx.google.com at your service, [158.181.68.197]
08-28 11:19:38.274: I/System.out(9492): 250-SIZE 35882577
08-28 11:19:38.274: I/System.out(9492): 250-8BITMIME
08-28 11:19:38.274: I/System.out(9492): 250-AUTH LOGIN PLAIN XOAUTH XOAUTH2 PLAIN-CLIENTTOKEN
08-28 11:19:38.274: I/System.out(9492): 250-ENHANCEDSTATUSCODES
08-28 11:19:38.274: I/System.out(9492): 250-PIPELINING
08-28 11:19:38.274: I/System.out(9492): 250-CHUNKING
08-28 11:19:38.334: I/System.out(9492): 250 SMTPUTF8
08-28 11:19:38.344: I/System.out(9492): DEBUG SMTP: Found extension "SIZE", arg "35882577"
08-28 11:19:38.344: I/System.out(9492): DEBUG SMTP: Found extension "8BITMIME", arg ""
08-28 11:19:38.394: I/System.out(9492): DEBUG SMTP: Found extension "AUTH", arg "LOGIN PLAIN XOAUTH XOAUTH2 PLAIN-CLIENTTOKEN"
08-28 11:19:38.424: I/System.out(9492): DEBUG SMTP: Found extension "ENHANCEDSTATUSCODES", arg ""
08-28 11:19:38.444: I/System.out(9492): DEBUG SMTP: Found extension "PIPELINING", arg ""
08-28 11:19:38.444: I/System.out(9492): DEBUG SMTP: Found extension "CHUNKING", arg ""
08-28 11:19:38.444: I/System.out(9492): DEBUG SMTP: Found extension "SMTPUTF8", arg ""
08-28 11:19:38.444: I/System.out(9492): DEBUG SMTP: Attempt to authenticate
08-28 11:19:38.504: I/System.out(9492): AUTH LOGIN
08-28 11:19:38.614: I/System.out(9492): 334 VXNlcm5hbWU6
08-28 11:19:38.614: I/System.out(9492): ZWIxNG1zQGdvb2dsZW1haWwuY29t
08-28 11:19:38.674: I/System.out(9492): 334 UGFzc3dvcmQ6
08-28 11:19:38.704: I/System.out(9492): RkZ3UzIwMDM=
08-28 11:19:39.044: I/System.out(9492): 534-5.7.14 <https://accounts.google.com/ContinueSignIn?sarp=1&scc=1&plt=AKgnsbsSi
08-28 11:19:39.084: I/System.out(9492): 534-5.7.14 WAPBKxXrfqaVMKdB7zRhISihBZWTJlb98chHX5cnpuqhm_KUO2czQYBBRTt4KObt7ntZSJ
08-28 11:19:39.084: I/System.out(9492): 534-5.7.14 QIqeHh6gs0Q2XQDVlZGCxCrGEsYoz5-1Qv7Tc98LT7lP6dO8gCnAbkydaRLbsmTfI8Xl-s
08-28 11:19:39.084: I/System.out(9492): 534-5.7.14 zG47TvmrvdIMiSF0R91lNdduhygKxOW-VCJcH8KADwJJkJeWxOQXK-uBA-YF2ZUnEMLWvV
08-28 11:19:39.134: I/System.out(9492): 534-5.7.14 LQKdhEA> Please log in via your web browser and then try again.
08-28 11:19:39.144: I/System.out(9492): 534-5.7.14 Learn more at
08-28 11:19:39.164: I/System.out(9492): 534 5.7.14 https://support.google.com/mail/bin/answer.py?answer=78754 wr10sm10759961wjc.10 - gsmtp
08-28 11:19:39.314: I/GMail(9492): Exception null

1 個解決方案

解決方案1
 0  2014-08-28 15:47:48

gmail似乎可以選擇阻止來自腳本的訪問，您可以通過以下方式啟用該功能：

Gmail的近期活動 。 應該處於異常活動狀態 。

編輯：

好吧，您正在使用tls（ port 587, isSSL false ）。

嘗試通過ssl連接，然后： 

Properties emailProperties = new Properties();
emailProperties.put("mail.smtp.host", "smtp.gmail.com");
emailProperties.put("mail.smtp.auth", "true");
emailProperties.put("mail.smtp.port", "465");
emailProperties.put("mail.smtp.socketFactory.port", "465");
emailProperties.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");

希望能解決您的問題。

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