发送邮件：java.net.SocketException：网络无法访问：连接
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Sending mail: java.net.SocketException: Network is unreachable: connect
提问by Sergey Azarkevich
Try send mail via javax.mail:
尝试通过 javax.mail 发送邮件：
Properties props = new Properties();
props.put("mail.smtp.host", "xxxxx");
props.put("mail.smtp.port", "25");
props.put("mail.smtp.auth", "false");
Session session = Session.getInstance(props,
new javax.mail.Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication("xx", "xx");
}
});
try {
Message message = new MimeMessage(session);
message.setFrom(new InternetAddress("xxxxx"));
message.setRecipients(Message.RecipientType.TO, InternetAddress.parse("xxxxx"));
message.setSubject("Subject");
message.setText("Body");
Transport.send(message);
System.out.println("Done");
} catch (MessagingException e) {
throw new RuntimeException(e);
}
It throw exception
它抛出异常
Exception in thread "main" java.lang.RuntimeException: javax.mail.MessagingException: Could not connect to SMTP host: srv-mail.imb.invention.com, port: 25;
nested exception is:
java.net.SocketException: Network is unreachable: connect
at foo.SendMailTest.main(SendMailTest.java:41)
Caused by: javax.mail.MessagingException: Could not connect to SMTP host: xxx.xxxx.zzzzz.com, port: 25;
nested exception is:
java.net.SocketException: Network is unreachable: connect
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1961)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:654)
at javax.mail.Service.connect(Service.java:295)
at javax.mail.Service.connect(Service.java:176)
at javax.mail.Service.connect(Service.java:125)
at javax.mail.Transport.send0(Transport.java:194)
at javax.mail.Transport.send(Transport.java:124)
at foo.SendMailTest.main(SendMailTest.java:36)
Caused by: java.net.SocketException: Network is unreachable: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:321)
at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:237)
at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1927)
... 7 more
Server available:
可用服务器：
C:\work\test>nc.exe xxx 25
220 xxx.zzz.aaaaaaa.com Microsoft ESMTP MAIL Service ready at Thu, 12 Sep 2013 15:10:45 +0300
ping also work.
平也工作。
Similar .net code work as expected.
类似的 .net 代码按预期工作。
I have no ideas what going wrong....
我不知道出了什么问题......
回答by Sergey Azarkevich
The answer is: java prefer IPv6, but something wrong with it in our company.
Adding property java.net.preferIPv4Stack=truesolves problem.
答案是：java 更喜欢 IPv6，但我们公司的它有问题。添加属性java.net.preferIPv4Stack=true可以解决问题。
