filebrowser.java

个人事务处理工具 一个简单的小软件

/*
 *
 * Copyright (c) 2007, Sun Microsystems, Inc.
 *
 * 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 Sun Microsystems 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.
 */
package example.fc;

import java.io.*;

import java.util.*;

import javax.microedition.io.*;
import javax.microedition.io.file.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;


/**
 * Demonstration MIDlet for File Connection API. This MIDlet implements simple
 * file browser for the filesystem available to the J2ME applications.
 *
 */
public class FileBrowser extends MIDlet implements CommandListener {
    private static final String[] attrList = { "Read", "Write", "Hidden" };
    private static final String[] typeList = { "Regular File", "Directory" };
    private static final String[] monthList =
        { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

    /* special string denotes upper directory */
    private static final String UP_DIRECTORY = "..";

    /* special string that denotes upper directory accessible by this browser.
     * this virtual directory contains all roots.
     */
    private static final String MEGA_ROOT = "/";

    /* separator string as defined by FC specification */
    private static final String SEP_STR = "/";

    /* separator character as defined by FC specification */
    private static final char SEP = '/';
    private String currDirName;
    private Command view = new Command("View", Command.ITEM, 1);
    private Command creat = new Command("New", Command.ITEM, 2);

    //add delete file functionality
    private Command delete = new Command("Delete", Command.ITEM, 3);
    private Command creatOK = new Command("OK", Command.OK, 1);
    private Command prop = new Command("Properties", Command.ITEM, 2);
    private Command back = new Command("Back", Command.BACK, 2);
    private Command exit = new Command("Exit", Command.EXIT, 3);
    private TextField nameInput; // Input field for new file name
    private ChoiceGroup typeInput; // Input field for file type (regular/dir)
    private Image dirIcon;
    private Image fileIcon;
    private Image[] iconList;

    public FileBrowser() {
        currDirName = MEGA_ROOT;

        try {
            dirIcon = Image.createImage("/icons/dir.png");
        } catch (IOException e) {
            dirIcon = null;
        }

        try {
            fileIcon = Image.createImage("/icons/file.png");
        } catch (IOException e) {
            fileIcon = null;
        }

        iconList = new Image[] { fileIcon, dirIcon };
    }

    public void startApp() {
        try {
            showCurrDir();
        } catch (SecurityException e) {
            Alert alert =
                new Alert("Error", "You are not authorized to access the restricted API", null,
                    AlertType.ERROR);
            alert.setTimeout(Alert.FOREVER);

            Form form = new Form("Cannot access FileConnection");
            form.append(new StringItem(null,
                    "You cannot run this MIDlet with the current permissions. " +
                    "Sign the MIDlet suite, or run it in a different security domain"));
            form.addCommand(exit);
            form.setCommandListener(this);
            Display.getDisplay(this).setCurrent(alert, form);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void pauseApp() {
    }

    public void destroyApp(boolean cond) {
        notifyDestroyed();
    }

    public void commandAction(Command c, Displayable d) {
        if (c == view) {
            List curr = (List)d;
            final String currFile = curr.getString(curr.getSelectedIndex());
            new Thread(new Runnable() {
                    public void run() {
                        if (currFile.endsWith(SEP_STR) || currFile.equals(UP_DIRECTORY)) {
                            traverseDirectory(currFile);
                        } else {
                            // Show file contents
                            showFile(currFile);
                        }
                    }
                }).start();
        } else if (c == prop) {
            List curr = (List)d;
            String currFile = curr.getString(curr.getSelectedIndex());

            showProperties(currFile);
        } else if (c == creat) {
            createFile();
        } else if (c == creatOK) {
            String newName = nameInput.getString();

            if ((newName == null) || newName.equals("")) {
                Alert alert =
                    new Alert("Error!", "File Name is empty. Please provide file name", null,
                        AlertType.ERROR);
                alert.setTimeout(Alert.FOREVER);
                Display.getDisplay(this).setCurrent(alert);
            } else {
                // Create file in a separate thread and disable all commands
                // except for "exit"
                executeCreateFile(newName, typeInput.getSelectedIndex() != 0);
                Display.getDisplay(this).getCurrent().removeCommand(creatOK);
                Display.getDisplay(this).getCurrent().removeCommand(back);
            }
        } else if (c == back) {
            showCurrDir();
        } else if (c == exit) {
            destroyApp(false);
        } else if (c == delete) {
            List curr = (List)d;
            String currFile = curr.getString(curr.getSelectedIndex());
            executeDelete(currFile);
        }
    }

    void delete(String currFile) {
        if (!currFile.equals(UP_DIRECTORY)) {
            if (currFile.endsWith(SEP_STR)) {
                checkDeleteFolder(currFile);
            } else {
                deleteFile(currFile);
                showCurrDir();
            }
        } else {
            Alert cantDeleteFolder =
                new Alert("Error!",
                    "Can not delete The up-directory (..) " + "symbol! not a real folder", null,
                    AlertType.ERROR);
            cantDeleteFolder.setTimeout(Alert.FOREVER);
            Display.getDisplay(this).setCurrent(cantDeleteFolder);
        }
    }

    private void executeDelete(String currFile) {
        final String file = currFile;
        new Thread(new Runnable() {
                public void run() {
                    delete(file);
                }
            }).start();
    }

    private void checkDeleteFolder(String folderName) {
        try {
            FileConnection fcdir =
                (FileConnection)Connector.open("file://localhost/" + currDirName + folderName);
            Enumeration content = fcdir.list("*", true);

            //only empty directory can be deleted
            if (!content.hasMoreElements()) {
                fcdir.delete();
                showCurrDir();
            } else {
                Alert cantDeleteFolder =
                    new Alert("Error!", "Can not delete The non-empty folder: " + folderName, null,
                        AlertType.ERROR);
                cantDeleteFolder.setTimeout(Alert.FOREVER);
                Display.getDisplay(this).setCurrent(cantDeleteFolder);
            }
        } catch (IOException ioe) {
            System.out.println(currDirName + folderName);

            ioe.printStackTrace();
        }
    }

    //Starts creatFile with another Thread
    private void executeCreateFile(final String name, final boolean val) {
        new Thread(new Runnable() {
                public void run() {
                    createFile(name, val);
                }
            }).start();
    }

    /**
     * Show file list in the current directory .