使用JavaMail從我的Gmail中讀取所有新郵件

Question

我有一個包含GUI的應用程序，它正在使用Javamail。 當我打開此Jframe我必須查看在jTextArea上發送到我的郵件的jTextArea 。

問題是當我編寫代碼時，它僅顯示最后發送的消息。

如何在收件箱中顯示所有新郵件？

這是我的代碼：

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {

Properties props = new Properties();

props.put("mail.pop3.host", "pop.gmail.com");

props.put("mail.pop3.user", "mymail@gmail.com");

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("mymail@gmail.com", "mypassword");

    }
});

try {
    Store store = session.getStore("pop3");

    store.connect("pop.gmail.com", "mymail@gmail.com", "mypaswword");

    Folder fldr = store.getFolder("INBOX");

    fldr.open(Folder.READ_ONLY);

    Message[] msg = fldr.getMessages();

    Address[] address;


    for (int i = 0; i < msg.length; i++) {

        jTextArea1.setText("SentDate : " + msg[i].getSentDate() + "\n" + "From : " + msg[i].getFrom()[0] + "\n" + "Subject : " + msg[i].getSubject() + "\n" + "Message : " + "\n" + msg[i].getContent().toString());

    }

    fldr.close(true);

    store.close();

} catch (Exception e) {
    System.out.println(e);
}

Answer 1

您可以在以下循環消息中反復將jTextArea1的文本設置為相同的內容：

for (int i = 0; i < msg.length; i++) {

    jTextArea1.setText("SentDate : " + msg[i].getSentDate() + "\n" + "From : " + msg[i].getFrom()[0] + "\n" + "Subject : " + msg[i].getSubject() + "\n" + "Message : " + "\n" + msg[i].getContent().toString());

}

您應該使用所有消息構建一個StringBuilder ，然后設置jTextArea1的內容

final StringBuilder sb = new StringBuilder();
for (int i = 0; i < msg.length; i++) {

    sb.append("SentDate : " + msg[i].getSentDate() + "\n" + "From : " + msg[i].getFrom()[0] + "\n" + "Subject : " + msg[i].getSubject() + "\n" + "Message : " + "\n" + msg[i].getContent().toString());

}
jTextArea1.setText(sb.toString());

然后，您可以通過使用增強的for循環並使用StringBuilder的append方法使這一點更加清晰。

final StringBuilder sb = new StringBuilder();
for (Message message : msg) {

    sb.append("SentDate : ").
            append(message.getSentDate()).
            append("\n").
            append("From : ").
            append(message.getFrom()[0]).
            append("\n").append("Subject : ").
            append(message.getSubject()).
            append("\n").
            append("Message : ").
            append("\n").
            append(message.getContent().toString());

}
jTextArea1.setText(sb.toString());

Answer 2

final StringBuilder sb = new StringBuilder();
for (Message message : msg) {

    sb.append("SentDate : ").
        append(message.getSentDate()).
        append("\n").
        append("From : ").
        append(message.getFrom()[0]).
        append("\n").append("Subject : ").
        append(message.getSubject()).
        append("\n").
        append("Message : ").
        append("\n").
        append(message.getContent().toString());

}
jTextArea1.setText(sb.toString());