java 在服务器上获取所有邮件

import java.util.Properties;

import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.Session;
import javax.mail.URLName;

public class MainClass {

public static void main(String[] args) throws Exception {
URLName server = new URLName("protocol://username:password@host/foldername");

Session session = Session.getDefaultInstance(new Properties(), null);

Folder folder = session.getFolder(server);
if (folder == null) {
System.out.println("Folder " + server.getFile() + " not found.");
System.exit(1);
}
folder.open(Folder.READ_ONLY);

// Get the messages from the server
Message[] messages = folder.getMessages();
for (int i = 0; i < messages.length; i++) {
System.out.println("------------ Message " + (i + 1) + " ------------");
messages[i].writeTo(System.out);
}

folder.close(false);
}
}