如何通过Java应用程序使用GMail,Yahoo或者Hotmail发送电子邮件?

时间:2020-03-05 18:48:28  来源:igfitidea点击:

是否可以使用GMail帐户从Java应用程序发送电子邮件?我已经用Java应用程序配置了我的公司邮件服务器来发送电子邮件,但是在分发应用程序时并不会减少它。任何使用Hotmail,Yahoo或者GMail的答案都是可以接受的。

解决方案

回答

一个简单的方法是为POP3访问配置/启用Gmail帐户。这将允许我们通过gmail服务器通过普通SMTP发送出去。

然后,我们只需通过smtp.gmail.com发送(在端口587上)

回答

这样的事情(听起来像我们只需要更改SMTP服务器):

String host = "smtp.gmail.com";
String from = "user name";
Properties props = System.getProperties();
props.put("mail.smtp.host", host);
props.put("mail.smtp.user", from);
props.put("mail.smtp.password", "asdfgh");
props.put("mail.smtp.port", "587"); // 587 is the port number of yahoo mail
props.put("mail.smtp.auth", "true");

Session session = Session.getDefaultInstance(props, null);
MimeMessage message = new MimeMessage(session);
message.setFrom(new InternetAddress(from));

InternetAddress[] to_address = new InternetAddress[to.length];
int i = 0;
// To get the array of addresses
while (to[i] != null) {
    to_address[i] = new InternetAddress(to[i]);
    i++;
}
System.out.println(Message.RecipientType.TO);
i = 0;
while (to_address[i] != null) {

    message.addRecipient(Message.RecipientType.TO, to_address[i]);
    i++;
}
message.setSubject("sending in a group");
message.setText("Welcome to JavaMail");
// alternately, to send HTML mail:
// message.setContent("<p>Welcome to JavaMail</p>", "text/html");
Transport transport = session.getTransport("smtp");
transport.connect("smtp.mail.yahoo.co.in", "user name", "asdfgh");
transport.sendMessage(message, message.getAllRecipients());
transport.close();

回答

首先下载JavaMail API,并确保相关的jar文件在类路径中。

这是一个使用GMail的完整示例。

import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;

public class Main {

    private static String USER_NAME = "*****";  // GMail user name (just the part before "@gmail.com")
    private static String PASSWORD = "********"; // GMail password
    private static String RECIPIENT = "[email protected]";

    public static void main(String[] args) {
        String from = USER_NAME;
        String pass = PASSWORD;
        String[] to = { RECIPIENT }; // list of recipient email addresses
        String subject = "Java send mail example";
        String body = "Welcome to JavaMail!";

        sendFromGMail(from, pass, to, subject, body);
    }

    private static void sendFromGMail(String from, String pass, String[] to, String subject, String body) {
        Properties props = System.getProperties();
        String host = "smtp.gmail.com";
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.host", host);
        props.put("mail.smtp.user", from);
        props.put("mail.smtp.password", pass);
        props.put("mail.smtp.port", "587");
        props.put("mail.smtp.auth", "true");

        Session session = Session.getDefaultInstance(props);
        MimeMessage message = new MimeMessage(session);

        try {
            message.setFrom(new InternetAddress(from));
            InternetAddress[] toAddress = new InternetAddress[to.length];

            // To get the array of addresses
            for( int i = 0; i < to.length; i++ ) {
                toAddress[i] = new InternetAddress(to[i]);
            }

            for( int i = 0; i < toAddress.length; i++) {
                message.addRecipient(Message.RecipientType.TO, toAddress[i]);
            }

            message.setSubject(subject);
            message.setText(body);
            Transport transport = session.getTransport("smtp");
            transport.connect(host, from, pass);
            transport.sendMessage(message, message.getAllRecipients());
            transport.close();
        }
        catch (AddressException ae) {
            ae.printStackTrace();
        }
        catch (MessagingException me) {
            me.printStackTrace();
        }
    }
}

自然地,我们将比在上面的示例代码中所做的那样,要在catch块中做更多的事情而不是打印堆栈跟踪。 (删除catch块以查看JavaMail API中的哪些方法调用会抛出异常,以便我们更好地了解如何正确处理它们。)

感谢@jodonnel和其他所有回答的人。我给他赏金是因为他的回答使我大约有95%的方式获得了完整的答案。

回答

即使这个问题已经关闭,我也想发布一个对策,但是现在使用简单Java Mail(开放源JavaMail smtp包装器):

final Email email = new Email();

String host = "smtp.gmail.com";
Integer port = 587;
String from = "username";
String pass = "password";
String[] to = {"[email protected]"};

email.setFromAddress("", from);
email.setSubject("sending in a group");
for( int i=0; i < to.length; i++ ) {
    email.addRecipient("", to[i], RecipientType.TO);
}
email.setText("Welcome to JavaMail");

new Mailer(host, port, from, pass).sendMail(email);
// you could also still use your mail session instead
new Mailer(session).sendMail(email);

回答

当我想发送带有附件的电子邮件时,这就是我的工作,可以正常工作。 :)

public class NewClass {

    public static void main(String[] args) {
        try {
            Properties props = System.getProperties();
            props.put("mail.smtp.starttls.enable", "true");
            props.put("mail.smtp.host", "smtp.gmail.com");
            props.put("mail.smtp.auth", "true");
            props.put("mail.smtp.port", "465"); // smtp port
            Authenticator auth = new Authenticator() {

                @Override
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication("username-gmail", "password-gmail");
                }
            };
            Session session = Session.getDefaultInstance(props, auth);
            MimeMessage msg = new MimeMessage(session);
            msg.setFrom(new InternetAddress("[email protected]"));
            msg.setSubject("Try attachment gmail");
            msg.setRecipient(RecipientType.TO, new InternetAddress("[email protected]"));
            //add atleast simple body
            MimeBodyPart body = new MimeBodyPart();
            body.setText("Try attachment");
            //do attachment
            MimeBodyPart attachMent = new MimeBodyPart();
            FileDataSource dataSource = new FileDataSource(new File("file-sent.txt"));
            attachMent.setDataHandler(new DataHandler(dataSource));
            attachMent.setFileName("file-sent.txt");
            attachMent.setDisposition(MimeBodyPart.ATTACHMENT);
            Multipart multipart = new MimeMultipart();
            multipart.addBodyPart(body);
            multipart.addBodyPart(attachMent);
            msg.setContent(multipart);
            Transport.send(msg);
        } catch (AddressException ex) {
            Logger.getLogger(NewClass.class.getName()).log(Level.SEVERE, null, ex);
        } catch (MessagingException ex) {
            Logger.getLogger(NewClass.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

}

回答

上面的其他人也有很好的答案,但是我想在这里补充我的经验。我发现,将Gmail用作Web应用程序的出站SMTP服务器时,Gmail仅允许我发送约10封左右的邮件,然后再进行反垃圾邮件响应,而我必须手动执行此步骤才能重新启用SMTP访问。当用户向我的系统注册时,我发送的电子邮件不是垃圾邮件,而是网站"欢迎"电子邮件。因此,YMMV,而且我不会将Gmail用于生产Web应用程序。如果我们是代表用户发送电子邮件,例如已安装的桌面应用程序(用户在其中输入自己的Gmail凭据),则可能会没事。

另外,如果我们使用的是Spring,以下是一个有效的配置,可以将Gmail用于出站SMTP:

<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
    <property name="defaultEncoding" value="UTF-8"/>
    <property name="host" value="smtp.gmail.com"/>
    <property name="port" value="465"/>
    <property name="username" value="${mail.username}"/>
    <property name="password" value="${mail.password}"/>
    <property name="javaMailProperties">
        <value>
            mail.debug=true
            mail.smtp.auth=true
            mail.smtp.socketFactory.class=java.net.SocketFactory
            mail.smtp.socketFactory.fallback=false
        </value>
    </property>
</bean>

回答

//set CLASSPATH=%CLASSPATH%;activation.jar;mail.jar
import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;

public class Mail
{
    String  d_email = "[email protected]",
            d_password = "****",
            d_host = "smtp.gmail.com",
            d_port  = "465",
            m_to = "[email protected]",
            m_subject = "Testing",
            m_text = "Hey, this is the testing email using smtp.gmail.com.";
    public static void main(String[] args)
    {
        String[] to={"[email protected]"};
        String[] cc={"[email protected]"};
        String[] bcc={"[email protected]"};
        //This is for google
        Mail.sendMail("[email protected]", "password", "smtp.gmail.com", 
                      "465", "true", "true", 
                      true, "javax.net.ssl.SSLSocketFactory", "false", 
                      to, cc, bcc, 
                      "hi baba don't send virus mails..", 
                      "This is my style...of reply..If u send virus mails..");
    }

    public synchronized static boolean sendMail(
        String userName, String passWord, String host, 
        String port, String starttls, String auth, 
        boolean debug, String socketFactoryClass, String fallback, 
        String[] to, String[] cc, String[] bcc, 
        String subject, String text) 
    {
        Properties props = new Properties();
        //Properties props=System.getProperties();
        props.put("mail.smtp.user", userName);
        props.put("mail.smtp.host", host);
        if(!"".equals(port))
            props.put("mail.smtp.port", port);
        if(!"".equals(starttls))
            props.put("mail.smtp.starttls.enable",starttls);
        props.put("mail.smtp.auth", auth);
        if(debug) {
            props.put("mail.smtp.debug", "true");
        } else {
            props.put("mail.smtp.debug", "false");         
        }
        if(!"".equals(port))
            props.put("mail.smtp.socketFactory.port", port);
        if(!"".equals(socketFactoryClass))
            props.put("mail.smtp.socketFactory.class",socketFactoryClass);
        if(!"".equals(fallback))
            props.put("mail.smtp.socketFactory.fallback", fallback);

        try
        {
            Session session = Session.getDefaultInstance(props, null);
            session.setDebug(debug);
            MimeMessage msg = new MimeMessage(session);
            msg.setText(text);
            msg.setSubject(subject);
            msg.setFrom(new InternetAddress("[email protected]"));
            for(int i=0;i<to.length;i++) {
                msg.addRecipient(Message.RecipientType.TO, 
                                 new InternetAddress(to[i]));
            }
            for(int i=0;i<cc.length;i++) {
                msg.addRecipient(Message.RecipientType.CC, 
                                 new InternetAddress(cc[i]));
            }
            for(int i=0;i<bcc.length;i++) {
                msg.addRecipient(Message.RecipientType.BCC, 
                                 new InternetAddress(bcc[i]));
            }
            msg.saveChanges();
            Transport transport = session.getTransport("smtp");
            transport.connect(host, userName, passWord);
            transport.sendMessage(msg, msg.getAllRecipients());
            transport.close();
            return true;
        }
        catch (Exception mex)
        {
            mex.printStackTrace();
            return false;
        }
    }

}