为什么我会得到这个异常？

发布于 2024-11-25 20:52:26 字数 659 浏览 8 评论 0原文

此方法给出了收件箱中的电子邮件数量。但它给了我这个例外：

javax.mail.MessagingException: Connect failed;
 nested exception is:
java.net.ConnectException: Connection timed out: connecterror

 Session session = Session.getInstance(new Properties());
    try {
        Store store  = session.getStore("pop3");
        store.connect("pop.gmail.com" , "username" , "password");
        Folder fldr = store.getFolder("INBOX");
        fldr.open(Folder.READ_WRITE);
        int count = fldr.getMessageCount();
        System.out.println(count);
    } catch(Exception exc) {
        System.out.println(exc + "error");
    }

原文

This method gives the number of emails in the inbox.But it gives me this exception :

javax.mail.MessagingException: Connect failed;
 nested exception is:
java.net.ConnectException: Connection timed out: connecterror

 Session session = Session.getInstance(new Properties());
    try {
        Store store  = session.getStore("pop3");
        store.connect("pop.gmail.com" , "username" , "password");
        Folder fldr = store.getFolder("INBOX");
        fldr.open(Folder.READ_WRITE);
        int count = fldr.getMessageCount();
        System.out.println(count);
    } catch(Exception exc) {
        System.out.println(exc + "error");
    }

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我不吻晚风 2024-12-02 20:52:26

试试这个：

Properties props = new Properties();
props.put("mail.pop3.host" , "pop.gmail.com");
props.put("mail.pop3.user" , "username");
// Start SSL connection
props.put("mail.pop3.socketFactory" , 995 );
props.put("mail.pop3.socketFactory.class" , "javax.net.ssl.SSLSocketFactory" );
props.put("mail.pop3.port" , 995);

Session session = Session.getDefaultInstance(props , new Authenticator() {
    @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication( "username" , "password");
            }
});
try {
    Store store  = session.getStore("pop3");
    store.connect("pop.gmail.com" , "username" , "password");
    Folder fldr = store.getFolder("INBOX");
    fldr.open(Folder.HOLDS_MESSAGES);
    int count = fldr.getMessageCount();
    System.out.println(count);
} catch(Exception exc) {
    System.out.println(exc + " error");
}

另请访问此问题

Try this :

Properties props = new Properties();
props.put("mail.pop3.host" , "pop.gmail.com");
props.put("mail.pop3.user" , "username");
// Start SSL connection
props.put("mail.pop3.socketFactory" , 995 );
props.put("mail.pop3.socketFactory.class" , "javax.net.ssl.SSLSocketFactory" );
props.put("mail.pop3.port" , 995);

Session session = Session.getDefaultInstance(props , new Authenticator() {
    @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication( "username" , "password");
            }
});
try {
    Store store  = session.getStore("pop3");
    store.connect("pop.gmail.com" , "username" , "password");
    Folder fldr = store.getFolder("INBOX");
    fldr.open(Folder.HOLDS_MESSAGES);
    int count = fldr.getMessageCount();
    System.out.println(count);
} catch(Exception exc) {
    System.out.println(exc + " error");
}

Also visit this question

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北方的韩爷 2024-12-02 20:52:26

可能是因为服务器拒绝连接。

尝试从“telnet”连接。一旦可以连接，那么您应该能够从 Java 程序进行连接。

以下是一些故障排除提示：

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你怎么敢 2024-12-02 20:52:26

尝试更改

store.connect("pop.gmail.com" , "username" , "password");

为

store.connect("pop.gmail.com" , 995, "username" , "password");

免责声明：我还没有对此进行测试。

Gmail 需要安全的 SSL 连接，而 javax.mail.Service 可能不提供该连接。不过，我认为更可能的解释是您没有连接到正确的端口，因此我明确为 Gmail 的 POP3 服务指定了正确的端口号。

Try changing

store.connect("pop.gmail.com" , "username" , "password");

store.connect("pop.gmail.com" , 995, "username" , "password");

Disclaimer: I have not tested this.

Gmail requires a secure SSL connection, and maybe javax.mail.Service isn't providing that. I think the more likely explanation, though, is that you're simply not connecting to the right port, so I've explicitly specified the correct port number for Gmail's POP3 service.

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