如何解决windows8中的java 7 FTP传输？

Question

我使用的是Windows8 x86和jdk_7，下面的代码编译得很好，没有错误。当我运行它的时候，它给了我这样的异常：

javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25;
   nested exception is:
java.net.SocketException: Permission denied: connect

现在，作为一种变通方法，我尝试添加以下行：

System.setProperty("java.net.preferIPv4Stack", "true");

这并没有解决问题，在互联网上研究了几个小时后，我注意到问题出在jdk_7和防火墙问题上。我甚至试过这个命令

netsh advfirewall set global StatefulFTP disable

这也不能解决问题。

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

public class SendFileEmail
{
  public static void main(String [] args)
  {
     System.setProperty("java.net.preferIPv4Stack", "true");
  // Recipient's email ID needs to be mentioned.
     String to = "tmadile@gmail.com";

  // Sender's email ID needs to be mentioned
     String from = "hareitse@gmail.com";

  // Assuming you are sending email from localhost
     String host = "localhost";

  // Get system properties
     Properties properties = System.getProperties();

  // Setup mail server
     properties.setProperty("mail.smtp.host", host);

  // Get the default Session object.
     Session session = Session.getDefaultInstance(properties);

     try{
     // Create a default MimeMessage object.
        MimeMessage message = new MimeMessage(session);

     // Set From: header field of the header.
        message.setFrom(new InternetAddress(from));

     // Set To: header field of the header.
        message.addRecipient(Message.RecipientType.TO,
                              new InternetAddress(to));

     // Set Subject: header field
        message.setSubject("This is the Subject Line!");

     // Create the message part 
        BodyPart messageBodyPart = new MimeBodyPart();

     // Fill the message
        messageBodyPart.setText("This is message body");

     // Create a multipar message
        Multipart multipart = new MimeMultipart();

     // Set text message part
        multipart.addBodyPart(messageBodyPart);

     // Part two is attachment
        messageBodyPart = new MimeBodyPart();
        String filename = "shh.jpg";
        DataSource source = new FileDataSource(filename);
        messageBodyPart.setDataHandler(new DataHandler(source));
        messageBodyPart.setFileName(filename);
        multipart.addBodyPart(messageBodyPart);

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

     // Send message
        Transport.send(message);
        System.out.println("Sent message successfully....");
     }
        catch (MessagingException mex) {
           mex.printStackTrace();
        }
  }
}

Answer 1

// Assuming you are sending email from localhost
String host = "localhost";
// Setup mail server
properties.setProperty("mail.smtp.host", host);

从我阅读您的代码和您的错误的方式来看，您似乎更像是试图从本地主机作为主机发送邮件，而实际上您正在尝试发送到位于端口25的本地主机的邮件服务器。如果您没有在本地主机上运行任何SMTP服务器，您将收到上述错误。您提供的代码不会为您启动任何SMTP服务器。您可能应该将host = "localhost“替换为您的smtp主机(可能还有其他设置，具体取决于您的smtp提供商需要什么)。