使用javax邮件发送不带Gmail的邮件

我正在尝试发送一封没有Gmail的电子邮件，并使用

javax.mail

。特别是，我使用两个文件：

mailSender.java

和

main活动

mailssender.java

：

package com.polito.gmail;

import java.util.Date;
import java.util.Properties;

import javax.activation.CommandMap;
import javax.activation.MailcapCommandMap;
import javax.mail.BodyPart;
import javax.mail.Multipart;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

public class mailSender extends javax.mail.Authenticator {
    private String _user;
    private String _pass;

    private String[] destAddr = {"user1@hotmail.it", "user2@gmail.com"};
    private String fromAddr = "from@gmail.com";

    private String _port;
    private String _sport;

    private String _host;

    private String _subject = "New Mail";
    private String _body;

    private boolean _auth;

    private boolean _debuggable;

    private Multipart _multipart;

    public mailSender() {
        _host = "smtp.gmail.com"; // default smtp server
        _port = "465"; // default smtp port
        _sport = "465"; // default socketfactory port

        _user = ""; // username
        _pass = ""; // password
        _body = ""; // email body

        _debuggable = false; // debug mode on or off - default off
        _auth = true; // smtp authentication - default on

        _multipart = new MimeMultipart();

        // There is something wrong with MailCap, javamail can not find a
        // handler for the multipart/mixed part, so this bit needs to be added.
        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);
    }

    public mailSender(String user, String pass) {
        this();
        _user = user;
        _pass = pass;
    }

    public boolean send() throws Exception {
        Properties props = _setProperties();

        if (!_user.equals("") && !_pass.equals("") && destAddr.length > 0
                && !fromAddr.equals("") && !_subject.equals("")
                && !_body.equals("")) {
            Session session = Session.getInstance(props, this);

            MimeMessage msg = new MimeMessage(session);

            msg.setFrom(new InternetAddress(fromAddr));

            InternetAddress[] addressTo = new InternetAddress[destAddr.length];
            for (int i = 0; i < destAddr.length; i++) {
                addressTo[i] = new InternetAddress(destAddr[i]);
            }
            msg.setRecipients(MimeMessage.RecipientType.TO, addressTo);

            msg.setSubject(_subject);
            msg.setSentDate(new Date());

            // setup message body
            BodyPart messageBodyPart = new MimeBodyPart();
            messageBodyPart.setText(_body);
            _multipart.addBodyPart(messageBodyPart);

            // Put parts in message
            msg.setContent(_multipart);

            // send email
            Transport.send(msg);

            return true;
        } else {
            return false;
        }
    }

    @Override
    public PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(_user, _pass);
    }

    private Properties _setProperties() {
        Properties props = new Properties();

        props.put("mail.smtp.host", _host);

        if (_debuggable) {
            props.put("mail.debug", "false");
        }

        if (_auth) {
            props.put("mail.smtp.auth", "true");
        }

        props.put("mail.smtp.port", _port);
        props.put("mail.smtp.socketFactory.port", _sport);
        props.put("mail.smtp.socketFactory.class",
                "javax.net.ssl.SSLSocketFactory");
        props.put("mail.smtp.socketFactory.fallback", "false");

        return props;
    }

    // the getters and setters
    public String getBody() {
        return _body;
    }

    public void setBody(String _body) {
        this._body = _body;
    }

mailSender sender = new mailSender("from@gmail.com","password");
        sender.setBody(prepareBody());
        try {

            if(sender.send()) { 
                    Toast.makeText(MainActivity.this, "Mail send", Toast.LENGTH_LONG).show();
                } else { 
                    Toast.makeText(MainActivity.this, "Mail not send", Toast.LENGTH_LONG).show();
                } 
} catch (Exception e) {
            Log.e("error", String.valueOf(e.getMessage()));
        }

我在清单文件中插入了

INTERNET

权限，并正确ping了

smtp.gmail.com

，但应用程序生成此异常：

01-10 11:06:52.238: E/AndroidRuntime(2001): FATAL EXCEPTION: main
01-10 11:06:52.238: E/AndroidRuntime(2001): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.polito.gmail/com.polito.gmail.MainActivity}: java.lang.NullPointerException
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2185)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2210)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.app.ActivityThread.access$600(ActivityThread.java:142)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1208)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.os.Handler.dispatchMessage(Handler.java:99)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.os.Looper.loop(Looper.java:137)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.app.ActivityThread.main(ActivityThread.java:4931)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at java.lang.reflect.Method.invokeNative(Native Method)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at java.lang.reflect.Method.invoke(Method.java:511)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:558)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at dalvik.system.NativeStart.main(Native Method)
01-10 11:06:52.238: E/AndroidRuntime(2001): Caused by: java.lang.NullPointerException
01-10 11:06:52.238: E/AndroidRuntime(2001):     at com.polito.gmail.MainActivity.onCreate(MainActivity.java:48)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.app.Activity.performCreate(Activity.java:5008)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
01-10 11:06:52.238: E/AndroidRuntime(2001):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2139)
01-10 11:06:52.238: E/AndroidRuntime(2001):     ... 11 more

---

有什么问题吗？

试试这个，它可能会对你有所帮助

mailSender sender = new mailSender("from@gmail.com","password");
    sender.setBody(prepareBody());
    try {

        if(sender.send()) { 
                Toast.makeText(MainActivity.this, "Mail send", Toast.LENGTH_LONG).show();
            } else { 
                Toast.makeText(MainActivity.this, "Mail not send", Toast.LENGTH_LONG).show();
            } 
} catch (Exception e) {
        if(e.getMessage() != null)
            Log.e("error", String.valueOf(e.getMessage()));
 }

---

您的代码似乎正确，请检查您是否收到邮件。发生异常是因为没有与异常相关的消息。尝试此操作以避免出现

NullPointerException

：

Log.e("error", String.valueOf(e));

更新： 为了更好地了解使用javamail处理异常的逻辑，请遵循以下步骤：

            try {
                sender.send();
               Toast.makeText(MainActivity.this, "Mail send", Toast.LENGTH_LONG).show();
            }
            catch (Exception e) {                   

                if (e.toString().equals("java.lang.NullPointerException"))                      
                    Toast.makeText(MainActivity.this, "Mail not send: Mail settings not configured", Toast.LENGTH_LONG).show();

                else if (e.toString().equals("javax.mail.AuthenticationFailedException"))                       
                    Toast.makeText(MainActivity.this, "Mail not send: Wrong Username or Password", Toast.LENGTH_LONG).show();

                else if (e.toString().equals("Invalid Addresses"))                      
                    Toast.makeText(MainActivity.this, "Mail not send: Invalid Address(es)", Toast.LENGTH_LONG).show();

                else
                    Toast.makeText(MainActivity.this, "Mail not send", Toast.LENGTH_LONG).show();                   

                }

---

MainActivity第48行中的NullPointerException第48行中写入的内容将行号张贴到O，以便我们可以知道MainActivity第48行中的内容是：Log.e（“错误”，String.valueOf（e.getMessage（））；我认为e.getMessage（）给出空消息，请使用debug检查它。插入您的代码，我的应用程序将打印此错误：01-10 11:33:09.277:e/error（2790）：空通过您的更改，我获得此错误：。在第43行，如果我忘记将其更改为

toString

，则还有其他错误（例如：getMessage（）.equals（“无效地址”））。因此，如果（e.toString（）.equals（“无效地址”））更改后，我的应用程序打印toast“Mail not send”替换此行

props.put（“Mail.smtp.host”），\u host）props.setProperty（“mail.host”、\u host）进行编码>

并添加这个

props.setProperty（“mail.transport.protocol”，“smtp”）使用您的代码“我的应用程序”输入catch，但打印nothing@hasmet我知道，因为e.getMessage在您打印e.getMessage（）之前是空的nulll@hasmet有关更多信息，请查看向导答案