Java 使用servlet发送邮件时在netBeans中显示未知主机异常

这是我的文件：

index.html

<form action="servlet/SendMail">
To:<input type="text" name="to"/><br/>
Subject:<input type="text" name="subject"><br/>
Text:<textarea rows="10" cols="70" name="msg"></textarea><br/>
<input type="submit" value="send">
</form>

java

import java.util.Properties;

import javax.mail.*;

import javax.mail.internet.InternetAddress;

import javax.mail.internet.MimeMessage;

public class Mailer {
public static void send(String to,String subject,String msg){

final String user="myid@gmail.com";

final String pass="*********";

Properties props = new Properties();

  props.setProperty("mail.smtp.port", "465");

    props.put("mail.transport.protocol", "smtp");

        props.setProperty("mail.smtp.socketFactory.port", "465");

        props.put("mail.smtp.socketFactory.class", 
"javax.net.ssl.SSLSocketFactory");
        props.setProperty("mail.smtp.host", "smtp.gmail.com");

        props.setProperty("mail.smtp.starttls.enable", "true");

        props.setProperty("mail.smtp.auth", "true");


Session session = Session.getInstance(props,

 new javax.mail.Authenticator() {

  protected PasswordAuthentication getPasswordAuthentication() {

   return new PasswordAuthentication(user,pass);

   }
});

try {
 MimeMessage message = new MimeMessage(session);

 message.setFrom(new InternetAddress(user));

 message.addRecipient(Message.RecipientType.TO,new InternetAddress(to));

 message.setSubject(subject);

 message.setText(msg);

 Transport.send(message);

 System.out.println("Done");

 } catch (MessagingException e) {

    throw new RuntimeException(e);
 }

}
}

---

你从哪里得到错误？有线索吗？类似于线程“main”java.lang.RuntimeException中的异常：javax.mail.MessaginException:无法连接到SMTP主机：SMTP.gmail.com，端口：587？？需要对代码进行一些调试。运行时是否连接了internet。是的，我连接了internet@Satya。@sheetal Mohan sharma我真的不知道哪里出了问题。

import java.util.Properties;

import javax.mail.*;

import javax.mail.internet.InternetAddress;

import javax.mail.internet.MimeMessage;

public class Mailer {
public static void send(String to,String subject,String msg){

final String user="myid@gmail.com";

final String pass="*********";

Properties props = new Properties();

  props.setProperty("mail.smtp.port", "465");

    props.put("mail.transport.protocol", "smtp");

        props.setProperty("mail.smtp.socketFactory.port", "465");

        props.put("mail.smtp.socketFactory.class", 
"javax.net.ssl.SSLSocketFactory");
        props.setProperty("mail.smtp.host", "smtp.gmail.com");

        props.setProperty("mail.smtp.starttls.enable", "true");

        props.setProperty("mail.smtp.auth", "true");


Session session = Session.getInstance(props,

 new javax.mail.Authenticator() {

  protected PasswordAuthentication getPasswordAuthentication() {

   return new PasswordAuthentication(user,pass);

   }
});

try {
 MimeMessage message = new MimeMessage(session);

 message.setFrom(new InternetAddress(user));

 message.addRecipient(Message.RecipientType.TO,new InternetAddress(to));

 message.setSubject(subject);

 message.setText(msg);

 Transport.send(message);

 System.out.println("Done");

 } catch (MessagingException e) {

    throw new RuntimeException(e);
 }

}
}