如何在 Java 中发送电子邮件？

Question

我需要从运行在 Tomcat 中的 servlet 发送电子邮件。我将始终以相同的主题发送给同一收件人，但内容不同。

用 Java 发送电子邮件的简单易行的方法是什么？

相关：

How do you send email from a Java app using GMail?

Answer 1

这是我的代码：

import javax.mail.*;
import javax.mail.internet.*;

// Set up the SMTP server.
java.util.Properties props = new java.util.Properties();
props.put("mail.smtp.host", "smtp.myisp.com");
Session session = Session.getDefaultInstance(props, null);

// Construct the message
String to = "you@you.com";
String from = "me@me.com";
String subject = "Hello";
Message msg = new MimeMessage(session);
try {
    msg.setFrom(new InternetAddress(from));
    msg.setRecipient(Message.RecipientType.TO, new InternetAddress(to));
    msg.setSubject(subject);
    msg.setText("Hi,\n\nHow are you?");

    // Send the message.
    Transport.send(msg);
} catch (MessagingException e) {
    // Error.
}

您可以在此处从 Sun 获取 JavaMail 库：http://java.sun.com/products/javamail/

Answer 2

JavaMail 使用起来可能有点麻烦。如果您想要一个更简单、更清洁的解决方案，请查看 JavaMail 的 Spring 包装器。参考文档在这里：

http://static.springframework.org/spring/docs/2.5.x/reference/mail.html

但是，这确实意味着您的应用程序中需要 Spring，如果这不是一个选项，那么您可以查看另一个开源包装器，例如 simple-java-mail：

simplejavamail.org

或者，您可以直接使用 JavaMail，但上述两种解决方案是使用 Java 发送电子邮件的更简单、更简洁的方式。

Answer 3

另一个包装 Java Mail API 的选项是 Apache's commons-email。

来自他们的User Guide.

SimpleEmail email = new SimpleEmail();
email.setHostName("mail.myserver.com");
email.addTo("jdoe@somewhere.org", "John Doe");
email.setFrom("me@apache.org", "Me");
email.setSubject("Test message");
email.setMsg("This is a simple test of commons-email");
email.send();

Answer 4

为了跟进 jon 的回复，这里有一个使用 simple-java-mail 发送邮件的示例。

这个想法是您不需要了解构成电子邮件的所有技术（嵌套）部分。从这个意义上说，它很像 Apache 的 commons-email，除了 Simple Java Mail 在处理附件和嵌入图像时比 Apache 的邮件 API 更简单一点。 Spring 的邮件功能也可以工作，但使用起来有点尴尬（例如，它需要一个匿名内部类），当然你需要依赖于 Spring，它不仅仅是一个简单的邮件库，因为它是设计的基础成为 IOC 解决方案。

Simple Java Mail btw 是 JavaMail API 的包装器。

final Email email = new Email();

email.setFromAddress("lollypop", "lolly.pop@somemail.com"); 
email.setSubject("hey");
email.addRecipient("C. Cane", "candycane@candyshop.org", RecipientType.TO);
email.addRecipient("C. Bo", "chocobo@candyshop.org", RecipientType.BCC); 
email.setText("We should meet up! ;)"); 
email.setTextHTML("<img src='cid:wink1'><b>We should meet up!</b><img src='cid:wink2'>");

// embed images and include downloadable attachments 
email.addEmbeddedImage("wink1", imageByteArray, "image/png");
email.addEmbeddedImage("wink2", imageDatesource); 
email.addAttachment("invitation", pdfByteArray, "application/pdf");
email.addAttachment("dresscode", odfDatasource);

new Mailer("smtp.host.com", 25, "username", "password").sendMail(email);
// or alternatively, pass in your own traditional MailSession object.
new Mailer(preconfiguredMailSession).sendMail(email);

• simple-java-mail
• Apache Commons mail
• Spring mail
• JavaMail

Answer 5

我通常在 tomcat 的 server.xml 文件的 GlobalNamingResources 部分中定义我的 javamail 会话，以便我的代码不依赖于配置参数：

<GlobalNamingResources>
    <Resource name="mail/Mail" auth="Container" type="javax.mail.Session"
              mail.smtp.host="localhost"/>
    ...
</GlobalNamingResources>

我通过 JNDI 获得会话：

    Context context = new InitialContext();
    Session sess = (Session) context.lookup("java:comp/env/mail/Mail");

    MimeMessage message = new MimeMessage(sess);
    message.setFrom(new InternetAddress(from));
    message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
    message.setSubject(subject, "UTF-8");
    message.setText(content, "UTF-8");
    Transport.send(message);

Answer 6

如果您可以依赖外部 SMTP 服务器，JavaMail 就很棒。但是，如果您必须是自己的 SMTP 服务器，请查看 Asprin。

Answer 7

使用 Java 邮件库

import javax.mail.*

...

Session mSession = Session.getDefaultInstance(new Properties());
Transport mTransport = null;
mTransport = mSession.getTransport("smtp");
mTransport.connect(cServer, cUser, cPass);
MimeMessage mMessage = new MimeMessage(mSession);
mTransport.sendMessage(mMessage,  mMessage.getAllRecipients());
mTransport.close();

这是我用来让应用程序发送电子邮件的代码的截断版本。显然，在发送之前将正文和收件人放入邮件中可能会更适合您。

maven 仓库位置是 artifactId: javax.mail, groupId: mail。

Answer 8

如果是非 maven 项目，请将 java.mail jar 添加到您的类路径中 将以下依赖项添加到您的 pom.xml 中执行代码

 <dependency>
        <groupId>javax.mail</groupId>
        <artifactId>mail</artifactId>
        <version>1.4</version>
    </dependency>

下面是测试代码

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

    import javax.mail.Authenticator;
    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;

    public class MailSendingDemo {
        static Properties properties = new Properties();
        static {
            properties.put("mail.smtp.host", "smtp.gmail.com");
            properties.put("mail.smtp.port", "587");
            properties.put("mail.smtp.auth", "true");
            properties.put("mail.smtp.starttls.enable", "true");
        }
        public static void main(String[] args) {
            String returnStatement = null;
            try {
                Authenticator auth = new Authenticator() {
                    public PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication("yourEmailId", "password");
                    }
                };
                Session session = Session.getInstance(properties, auth);
                Message message = new MimeMessage(session);
                message.setFrom(new InternetAddress("yourEmailId"));            
                message.setRecipient(Message.RecipientType.TO, new InternetAddress("recepeientMailId"));
                message.setSentDate(new Date());
                message.setSubject("Test Mail");
                message.setText("Hi");
                returnStatement = "The e-mail was sent successfully";
                System.out.println(returnStatement);    
                Transport.send(message);
            } catch (Exception e) {
                returnStatement = "error in sending mail";
                e.printStackTrace();
            }
        }
    }

Answer 9

测试代码发送带有附件的邮件：

  public class SendMailNotificationWithAttachment {

            public static void mailToSendWithAttachment(String messageTosend, String snapShotFile) {

                String to = Constants.MailTo;
                String from = Constants.MailFrom;
                String host = Constants.smtpHost;// or IP address
                String subject = Constants.subject;
                // Get the session object
                Properties properties = System.getProperties();
                properties.setProperty("mail.smtp.host", host);
                Session session = Session.getDefaultInstance(properties);
                try {
                    MimeMessage message = new MimeMessage(session);
                    message.setFrom(new InternetAddress(from));
                    message.addRecipients(Message.RecipientType.TO, InternetAddress.parse(to));
                    message.setSubject(subject);
                    // message.setText(messageTosend);
                    BodyPart messageBodyPart = new MimeBodyPart();
                    messageBodyPart.setText(messageTosend);
                    Multipart multipart = new MimeMultipart();
                    multipart.addBodyPart(messageBodyPart);

                    messageBodyPart = new MimeBodyPart();
                    String filepath = snapShotFile;

                    DataSource source = new FileDataSource(filepath);
                    messageBodyPart.setDataHandler(new DataHandler(source));

                    Path p = Paths.get(filepath);
                    String NameOffile = p.getFileName().toString();

                    messageBodyPart.setFileName(NameOffile);
                    multipart.addBodyPart(messageBodyPart);

                    // Send the complete message parts
                    message.setContent(multipart);

                    // Send message
                    Transport.send(message);

        //          Log.info("Message is sent Successfully");
        //          System.out.println("Message is sent Successfully");
                    System.out.println("Message is sent Successfully");
    } catch (MessagingException e) {
    //          Log.error("Mail sending is Failed " + "due to" + e);
                SendMailNotificationWithAttachment smnwa = new SendMailNotificationWithAttachment();
                smnwa.mailSendFailed(e);
                throw new RuntimeException(e);
            }
        }
public void mailSendFailed(MessagingException e) {
        System.out.println("Mail sending is Failed " + "due to" + e);
        Log log = new Log();
        log.writeIntoLog("Mail sending is Failed " + "due to" + e.toString(), false);
    }

}

Answer 10

这是简单的解决方案

下载这些罐子： 1.Java邮箱 2. smtp 3.Java.mail

从[http://javapapers.com/core-java/java-email/][1]复制并粘贴以下代码

编辑收件人邮箱、用户名和密码（Gmail 用户 ID 和密码）

Answer 11

import java.util.Properties;

import javax.mail.Authenticator;
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;



public class sendMail {

    static  String  alertByEmail(String emailMessage){
        try{
                     
            final String fromEmail = "abc@gmail.com";
            final String password = "********"; //fromEmail password 
            final String toEmail = "xyz@gmail.com";
            System.out.println("Email configuration code start");
            Properties props = new Properties();
            props.put("mail.smtp.host", "smtp.gmail.com"); //SMTP Host set by default this
            props.put("mail.smtp.port", "587"); //TLS Port you can use 465 insted of 587
            props.put("mail.smtp.auth", "true"); //enable authentication
            props.put("mail.smtp.starttls.enable", "true"); //enable STARTTLS
            //create Authenticator object to pass in Session.getInstance argument
            Authenticator auth = new Authenticator() 
            {
            
                protected PasswordAuthentication getPasswordAuthentication() 
                {
                        return new PasswordAuthentication(fromEmail, password);
                }
            };
                        Session session = Session.getInstance(props, auth);
            
                        MimeMessage message = new MimeMessage(session);
                        message.setFrom(new InternetAddress(fromEmail));
                        message.addRecipient(Message.RecipientType.TO, new 
                                                              InternetAddress(toEmail));
                        message.setSubject("ALERT");
                        message.setText(emailMessage);//here you can write a msg what you want to send... just remove String parameter in alertByEmail method oherwise call parameter
                        System.out.println("text:"+emailMessage);
                        Transport.send(message);//here mail sending process start.
                        System.out.println("Mail Sent Successfully");
        }
        catch(Exception ex)
        {
                        System.out.println("Mail fail");
                        System.out.println(ex);
        }
        return emailMessage;
        
        }
public static void main(String[] args) {
    String emailMessage = "This mail is send using java code.Report as a spam";
    alertByEmail(emailMessage);
    }
}











https://github.com/sumitfadale/java-important-codes/blob/main/Send%20a%20mail%20through%20java 


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