fileutils.java.svn-base

来自「cqME :java framework for TCK test.」· SVN-BASE 代码 · 共 230 行

/*
 * $Id$
 *
 * Copyright 1996-2007 Sun Microsystems, Inc. All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 only, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License version 2 for more details (a copy is
 * included at /legal/license.txt).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this work; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
 * Clara, CA 95054 or visit www.sun.com if you need additional
 * information or have any questions.
 *
 */
package com.sun.tck.j2me.utils;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.channels.FileChannel;

/**
 * Utilities for operating with files and directories.
 */
public final class FileUtils {
    
    /**
     * Creation of instances is not allowed.
     */
    private FileUtils() {
    }
    
    /**
     * Copies source file to destination file. If destination file
     * doesn't exists, it's created.
     *
     * @param   srcFile     source file.
     * @param   destFile    destination file.
     * @param   overwrite   whether the destination file should be overwritten
     *
     * @return  <code>true</code> if the file was successfully copied to
     *          destination file, or <code>false</code> if destination file
     *          already exists and <code>overwrite</code> is <code>false</code>.
     *
     * @exception   IOException if I/O error occurs, or destination file cannot
     *      be created.
     */
    public static boolean copyFile(File srcFile, File destFile,
            boolean overwrite) throws IOException {
        return copyStreamToFile(new FileInputStream(srcFile), destFile,
                overwrite);
    }
    
    /**
     * Copies source file to destination directory. New file is created in the
     * destination directory with the same name as the source file. If the 
     * destination file already exists, it can be overwritten depending on
     * value of <code>overwrite</code> parameter.
     *
     * @param   srcFile     source file.
     * @param   destDir     destination directory.
     * @param   overwrite   whether the destination file should be overwritten
     *
     * @return  <code>true</code> if the file was successfully copied to
     *          destination directory, or <code>false</code> if file with same
     *          name already exists in the destination directory and 
     *          <code>overwrite</code> is <code>false</code>.
     *
     * @exception   IOException if I/O error occurs, or destination file cannot
     *      be created.
     */
    public static boolean copyFileToDir(File srcFile, File destDir,
            boolean overwrite) throws IOException {
        return copyFile(srcFile, new File(destDir, srcFile.getName()),
                overwrite);
    }
    
    /**
     * Copies source file to destination directory. New file is created in the
     * destination directory with the same name as the source file. If the 
     * destination file already exists, it can be overwritten depending on
     * value of <code>overwrite</code> parameter. If the destination directory
     * doesn't exist, it can be created depending on value of <code>createDir
     * </code> parameter.
     *
     * @param   srcFile     source file.
     * @param   destDir     destination directory.
     * @param   overwrite   whether the destination file should be overwritten
     * @param   createDir   whether the destination directory should be created
     *
     * @return  <code>true</code> if the file was successfully copied to
     *          destination directory, or <code>false</code> if file with same
     *          name already exists in the destination directory and 
     *          <code>overwrite</code> is <code>false</code>. Returns <code>
     *          false</code> if destination directory doesn't exist and cannot
     *          be created and if <code>createdDir</code> is <code>true</code>.
     *
     * @exception   IOException if I/O error occurs, or destination file cannot
     *      be created.
     */
    public static boolean copyFileToDir(File srcFile, File destDir,
            boolean overwrite, boolean createDir) throws IOException {
        if (!destDir.exists()) {
            if (!createDir) {
                return false;
            }
            if (!destDir.mkdirs()) {
                return false;
            }
        }
        return copyFileToDir(srcFile, destDir, overwrite);
    }
    
    /**
     * Reads the input stream and copies all read bytes to destination file. 
     * Stops when the end of the input stream is reached. If destination file
     * doesn't exists, it's created.
     *
     * @param   in  <code>InputStream</code> to copy bytes from.
     * @param   destFile    destination file.
     * @param   overwrite   whether the destination file should be overwritten
     *
     * @return  <code>true</code> if the input was successfully copied to
     *          destination file, or <code>false</code> if destination file
     *          already exists and <code>overwrite</code> is <code>false</code>.
     *
     * @exception   IOException if I/O error occurs, or destination file cannot
     *      be created.
     */
    public static boolean copyStreamToFile(InputStream in, File destFile,
            boolean overwrite) throws IOException {
        int bytesRead;
        byte [] buffer = new byte[4096];
        FileOutputStream out = null;
        
        try {
            if (destFile.exists()) {
                if (!overwrite) {
                    return false;
                }
            } else {
                if (!destFile.createNewFile()) {
                    throw new IOException("Cannot create destination file: "
                            + destFile.getPath());
                }   
            }

            out = new FileOutputStream(destFile, false);
            while ((bytesRead = in.read(buffer)) != -1) {
                out.write(buffer, 0, bytesRead);
            }
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
            } catch (IOException e) {}
            try {
                in.close();
            } catch (IOException e) {}
        }
        
        return true;
    }
    /**
     * Clears the content of the specified directory including subdirectories.
     * Leaves the specified directory empty.
     *
     * @param   dir     directory to be cleaned.   
     *
     * @exception   IOException if failed to delete a file or subdirectory.
     */
    public static void clearDir(File dir) throws IOException {
        if (!dir.exists()) {
            return;
        }
        File[] files = dir.listFiles();
        for (File f : files) {
            if (f.isDirectory()) {
                clearDir(f);
            }
            if (!f.delete()) {
                throw new IOException("Cannot delete: " + f.getPath());
            }
        }
    }
    
    /**
     * Copies the whole content of the source directory to the destination
     * directory. If destination directory doesn't exist, it's created.
     *
     * @param   srcDir  Source directory.
     * @param   destDir Destination directory.
     *
     * @exception   IOException if an I/O error occurs, or destination directory
     *              cannot be created, or some content cannot be copied.
     */
    public static void copyDir(File srcDir, File destDir) throws IOException {
        if (!destDir.exists() && !destDir.mkdirs()) {
            throw new IOException("Cannot create directory: " 
                    + destDir.getPath());
        }
        File[] content = srcDir.listFiles();
        for (File file : content) {
            if (file.isDirectory()) {
                copyDir(file, new File(destDir, file.getName()));
            }
            if (file.isFile()) {
                copyFileToDir(file, destDir, true);
            }
        }
    }
    
}