国外商业广告图片:J2EE的程序有异常,请帮忙解说。

import java.util.Properties;
import javax.mail.*;
import javax.mail.internet.*;

public class JDMailReader
{
public static void main(String[] args) throws Exception
{
if(args.length<2)
{
useage();
}
Properties props=new Properties();
Session session=Session.getDefaultInstance(props,null);
Store store=session.getStore("pop3");
store.connect("www.163.com",args[0],args[1]);
Folder folder=store.getFolder("INBOX");
folder.open(Folder.READ_ONLY);
Message messages[]=folder.getMessages();
for(int i=0;i<messages.length;i++)
{
messages[i].writeTo(System.out);
System.out.println("--------------------------------------");
}
folder.close(false);
store.close();
}
public static void useage()
{
System.out.println("Usage:java JDMailReader <username> <password>");
System.exit(1);
}
}
请调试！！！