Reading all new messages from my gmail using javamail

问题

I have an application which contains a GUI, it is using Javamail. When i open this Jframe I have to see messages that are sent to my mail on a jTextArea.

The problem is when i wrote my code it only shows just the last message sent.

How do I display all new messages in my inbox?

This is my code :

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);
}

回答1:

You repeatedly set the text of the jTextArea1 to the same contents in your loop over messages here:

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());

}

You should build a StringBuilder with all the messages and then set the contents of the jTextArea1

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());

You can then make this a lot more legible by using an enhanced for loop and using the append method of the StringBuilder.

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());

回答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());

来源：https://stackoverflow.com/questions/15906799/reading-all-new-messages-from-my-gmail-using-javamail

标签

java

jframe

javamail

jtextarea