Recipe 19.8 Program: MailReaderBean

Example 19-10 shows the complete MailReaderBean program. As the name implies, it can be used as a bean in larger programs but also has a main method for standalone use. Clicking on a message displays it in the message view part of the window; this is handled by the TreeSelectionListener called tsl.

Example 19-10. MailReaderBean.java

import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.tree.*; import javax.swing.event.*; import javax.mail.*; import javax.mail.internet.*; /**  * Display a mailbox or mailboxes.  * This is the generic version in javasrc/email, split off from  * JabaDex because of the latter's domain-specific "implements module" stuff.  */ public class MailReaderBean extends JSplitPane {     private JTextArea bodyText;     /* Construct a mail reader bean with all defaults.      */     public MailReaderBean( ) throws Exception {         this("smtp", "mailhost", "user", "nopasswd", "/");     }     /* Construct a mail reader bean with all values. */     public MailReaderBean(         String protocol,         String host,         String user,         String password,         String rootName)     throws Exception {         super(VERTICAL_SPLIT);         boolean recursive = false;         // Start with a Mail Session object         Session session = Session.getDefaultInstance(             System.getProperties( ), null);         session.setDebug(false);         // Get a Store object for the given protocol         Store store = session.getStore(protocol);         store.connect(host, user, password);         // Get Folder object for root, and list it         // If root name = "", getDefaultFolder( ), else getFolder(root)         FolderNode top;         if (rootName.length( ) != 0) {             // System.out.println("Getting folder " + rootName + ".");             top = new FolderNode(store.getFolder(rootName));         } else {             // System.out.println("Getting default folder.");             top = new FolderNode(store.getDefaultFolder( ));         }         if (top == null || !top.f.exists( )) {             System.out.println("Invalid folder " + rootName);             return;         }         if (top.f.getType( ) == Folder.HOLDS_FOLDERS) {             Folder[] f = top.f.list( );             for (int i = 0; i < f.length; i++)                 listFolder(top, new FolderNode(f[i]), recursive);         } else                 listFolder(top, top, false);         // Now that (all) the foldernodes and treenodes are in,         // construct a JTree object from the top of the list down,         // make the JTree scrollable (put in JScrollPane),         // and add it as the MailComposeBean's Northern child.         JTree tree = new JTree(top);         JScrollPane treeScroller = new JScrollPane(tree);         treeScroller.setBackground(tree.getBackground( ));         this.setTopComponent(treeScroller);         // The Southern (Bottom) child is a textarea to display the msg.         bodyText = new JTextArea(15, 80);         this.setBottomComponent(new JScrollPane(bodyText));         // Add a notification listener for the tree; this will         // display the clicked-upon message         TreeSelectionListener tsl = new TreeSelectionListener( ) {             public void valueChanged(TreeSelectionEvent evt) {                 Object[] po = evt.getPath( ).getPath( );    // yes, repeat it.                 Object o = po[po.length - 1];    // last node in path                 if (o instanceof FolderNode) {                     // System.out.println("Select folder " + o.toString( ));                     return;                 }                 if (o instanceof MessageNode) {                     bodyText.setText("");                     try {                         Message m = ((MessageNode)o).m;                         bodyText.append("To: ");                         Object[] tos = m.getAllRecipients( );                         for (int i=0; i<tos.length; i++) {                             bodyText.append(tos[i].toString( ));                             bodyText.append(" ");                         }                         bodyText.append("\n");                         bodyText.append("Subject: " + m.getSubject( ) + "\n");                         bodyText.append("From: ");                         Object[] froms = m.getFrom( );                         for (int i=0; i<froms.length; i++) {                             bodyText.append(froms[i].toString( ));                             bodyText.append(" ");                         }                         bodyText.append("\n");                         bodyText.append("Date: " + m.getSentDate( ) + "\n");                         bodyText.append("\n");                         bodyText.append(m.getContent( ).toString( ));                         // Start reading at top of message(!)                         bodyText.setCaretPosition(0);                     } catch (Exception e) {                         bodyText.append(e.toString( ));                     }                 } else                      System.err.println("UNEXPECTED SELECTION: " + o.getClass( ));             }         };         tree.addTreeSelectionListener(tsl);     }     static void listFolder(FolderNode top, FolderNode folder, boolean recurse)     throws Exception {         // System.out.println(folder.f.getName( ) + folder.f.getFullName( ));         if ((folder.f.getType( ) & Folder.HOLDS_MESSAGES) != 0) {             Message[] msgs = folder.f.getMessages( );             for (int i=0; i<msgs.length; i++) {                 MessageNode m = new MessageNode(msgs[i]);                 Address from = m.m.getFrom( )[0];                 String fromAddress;                 if (from instanceof InternetAddress)                     fromAddress = ((InternetAddress)from).getAddress( );                 else                     fromAddress = from.toString( );                 top.add(new MessageNode(msgs[i]));             }         }         if ((folder.f.getType( ) & Folder.HOLDS_FOLDERS) != 0) {             if (recurse) {                 Folder[] f = folder.f.list( );                 for (int i=0; i < f.length; i++)                     listFolder(new FolderNode(f[i]), top, recurse);                 }         }     }     /* Test unit - main program */     public static void main(String[] args) throws Exception {         final JFrame jf = new JFrame("MailReaderBean");         String mbox = "/var/mail/ian";         if (args.length > 0)             mbox = args[0];         MailReaderBean mb = new MailReaderBean("mbox", "localhost",             "", "", mbox);         jf.getContentPane( ).add(mb);         jf.setSize(640,480);         jf.setVisible(true);         jf.addWindowListener(new WindowAdapter( ) {             public void windowClosing(WindowEvent e) {             jf.setVisible(false);             jf.dispose( );             System.exit(0);             }         });     } }

It's a minimal, but working, mail reader. I'll merge it with a mail sender in Recipe 19.9 to make a complete mail client program.