Java tutorial
/* * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of Oracle nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ import javax.swing.tree.DefaultMutableTreeNode; import javax.mail.Store; import javax.mail.Folder; import javax.mail.MessagingException; /** * Node which represents a Folder in the javax.mail apis. * * @author Christopher Cotton */ public class FolderTreeNode extends DefaultMutableTreeNode { protected Folder folder = null; protected boolean hasLoaded = false; /** * creates a tree node that points to the particular Store. * * @param what the store for this node */ public FolderTreeNode(Folder what) { super(what); folder = what; } /** * a Folder is a leaf if it cannot contain sub folders */ public boolean isLeaf() { try { if ((folder.getType() & Folder.HOLDS_FOLDERS) == 0) return true; } catch (MessagingException me) { } // otherwise it does hold folders, and therefore not // a leaf return false; } /** * returns the folder for this node */ public Folder getFolder() { return folder; } /** * return the number of children for this folder node. The first * time this method is called we load up all of the folders * under the store's defaultFolder */ public int getChildCount() { if (!hasLoaded) { loadChildren(); } return super.getChildCount(); } protected void loadChildren() { // if it is a leaf, just say we have loaded them if (isLeaf()) { hasLoaded = true; return; } try { // Folder[] sub = folder.listSubscribed(); Folder[] sub = folder.list(); // add a FolderTreeNode for each Folder int num = sub.length; for (int i = 0; i < num; i++) { FolderTreeNode node = new FolderTreeNode(sub[i]); // we used insert here, since add() would make // another recursive call to getChildCount(); insert(node, i); } } catch (MessagingException me) { me.printStackTrace(); } } /** * override toString() since we only want to display a folder's * name, and not the full path of the folder */ public String toString() { return folder.getName(); } }