在不使用默认/内置应用程序的情况下使用 JavaMail API 在 Android 中发送电子邮件

Question

我正在尝试在 Android 中创建一个邮件发送应用程序。

如果我使用：

 Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);

这将启动内置的 Android 应用程序；我试图在 不 使用此应用程序的情况下直接单击按钮发送邮件。

原文由 Vinayak Bevinakatti 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 1

使用 Gmail 身份验证在 Android 中使用 JavaMail API 发送电子邮件。

创建示例项目的步骤：

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("[e-mail]", "password");
                    sender.sendMail("This is Subject",
                            "This is Body",
                            "[e-mail]",
                            "[e-mail]");
                } catch (Exception e) {
                    Log.e("SendMail", e.getMessage(), e);
                }

            }
        });

    }
}

GMailSender.java：

 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：

 /*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/**
 * @author Alexander Y. Kleymenov
 * @version $Revision$
 */

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;
            }
        });
    }
}

将在以下链接中找到的 3 个罐子添加到您的 Android 项目

• 邮件.jar
• 激活.jar
• 附加.jar

单击此处 - 如何添加外部 Jar

并且不要忘记在您的清单中添加这一行：

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

只需点击下面的链接即可更改安全性较低的应用程序的帐户访问权限 https://www.google.com/settings/security/lesssecureapps

运行该项目并检查邮件的收件人邮件帐户。干杯!

PS 并且不要忘记您不能从 android 中的任何 Activity 进行网络操作。因此，建议使用 AsyncTask 或 IntentService 以避免网络主线程异常。

Jar 文件： https ://code.google.com/archive/p/javamail-android/

原文由 Vinayak Bevinakatti 发布，翻译遵循 CC BY-SA 4.0 许可协议

Answer 2

感谢您提供宝贵的信息。代码工作正常。我也可以通过添加以下代码来添加附件。

 private Multipart _multipart;
_multipart = new MimeMultipart();

public void addAttachment(String filename,String subject) throws Exception {
    BodyPart messageBodyPart = new MimeBodyPart();
    DataSource source = new FileDataSource(filename);
    messageBodyPart.setDataHandler(new DataHandler(source));
    messageBodyPart.setFileName(filename);
    _multipart.addBodyPart(messageBodyPart);

    BodyPart messageBodyPart2 = new MimeBodyPart();
    messageBodyPart2.setText(subject);

    _multipart.addBodyPart(messageBodyPart2);
}

message.setContent(_multipart);

原文由 Krishna 发布，翻译遵循 CC BY-SA 3.0 许可协议