Java tutorial
/* * Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002. * All rights reserved. Software written by Ian F. Darwin and others. * $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $ * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. * * Java, the Duke mascot, and all variants of Sun's Java "steaming coffee * cup" logo are trademarks of Sun Microsystems. Sun's, and James Gosling's, * pioneering role in inventing and promulgating (and standardizing) the Java * language and environment is gratefully acknowledged. * * The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for * inventing predecessor languages C and C++ is also gratefully acknowledged. */ import java.awt.BorderLayout; import java.awt.Color; import java.awt.Container; import java.awt.Dimension; import java.io.File; import java.util.Collections; import java.util.Vector; import javax.swing.BoxLayout; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTree; import javax.swing.event.TreeSelectionEvent; import javax.swing.event.TreeSelectionListener; import javax.swing.tree.DefaultMutableTreeNode; /** * Display a file system in a JTree view * * @version $Id: FileTree.java,v 1.9 2004/02/23 03:39:22 ian Exp $ * @author Ian Darwin */ public class FileTree extends JPanel { /** Construct a FileTree */ public FileTree(File dir) { setLayout(new BorderLayout()); // Make a tree list with all the nodes, and make it a JTree JTree tree = new JTree(addNodes(null, dir)); // Add a listener tree.addTreeSelectionListener(new TreeSelectionListener() { public void valueChanged(TreeSelectionEvent e) { DefaultMutableTreeNode node = (DefaultMutableTreeNode) e.getPath().getLastPathComponent(); System.out.println("You selected " + node); } }); // Lastly, put the JTree into a JScrollPane. JScrollPane scrollpane = new JScrollPane(); scrollpane.getViewport().add(tree); add(BorderLayout.CENTER, scrollpane); } /** Add nodes from under "dir" into curTop. Highly recursive. */ DefaultMutableTreeNode addNodes(DefaultMutableTreeNode curTop, File dir) { String curPath = dir.getPath(); DefaultMutableTreeNode curDir = new DefaultMutableTreeNode(curPath); if (curTop != null) { // should only be null at root curTop.add(curDir); } Vector ol = new Vector(); String[] tmp = dir.list(); for (int i = 0; i < tmp.length; i++) ol.addElement(tmp[i]); Collections.sort(ol, String.CASE_INSENSITIVE_ORDER); File f; Vector files = new Vector(); // Make two passes, one for Dirs and one for Files. This is #1. for (int i = 0; i < ol.size(); i++) { String thisObject = (String) ol.elementAt(i); String newPath; if (curPath.equals(".")) newPath = thisObject; else newPath = curPath + File.separator + thisObject; if ((f = new File(newPath)).isDirectory()) addNodes(curDir, f); else files.addElement(thisObject); } // Pass two: for files. for (int fnum = 0; fnum < files.size(); fnum++) curDir.add(new DefaultMutableTreeNode(files.elementAt(fnum))); return curDir; } public Dimension getMinimumSize() { return new Dimension(200, 400); } public Dimension getPreferredSize() { return new Dimension(200, 400); } /** Main: make a Frame, add a FileTree */ public static void main(String[] av) { JFrame frame = new JFrame("FileTree"); frame.setForeground(Color.black); frame.setBackground(Color.lightGray); Container cp = frame.getContentPane(); if (av.length == 0) { cp.add(new FileTree(new File("."))); } else { cp.setLayout(new BoxLayout(cp, BoxLayout.X_AXIS)); for (int i = 0; i < av.length; i++) cp.add(new FileTree(new File(av[i]))); } frame.pack(); frame.setVisible(true); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } }