Java Directory Copy nio copyDirectory(final File srcDir, final File destDir)

Description

copy Directory

License

Apache License

Declaration

public static void copyDirectory(final File srcDir, final File destDir) throws IOException 

Method Source Code

//package com.java2s;
/**/*from w  w  w.  jav a2 s.  c  o m*/
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * <p/>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p/>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.*;
import java.nio.channels.FileChannel;

public class Main {
    private static final long FILE_COPY_BUFFER_SIZE = 1024 * 30;

    public static void copyDirectory(final File srcDir, final File destDir) throws IOException {
        if (srcDir == null || !srcDir.exists())
            return;
        if (destDir == null || !destDir.exists())
            destDir.mkdirs();
        // recurse
        final File[] srcFiles = srcDir.listFiles();
        if (srcFiles == null) { // null if abstract pathname does not denote a directory, or if an I/O error occurs
            throw new IOException("Failed to list contents of " + srcDir);
        }
        if (destDir.exists()) {
            if (destDir.isDirectory() == false) {
                throw new IOException("Destination '" + destDir + "' exists but is not a directory");
            }
        } else {
            if (!destDir.mkdirs() && !destDir.isDirectory()) {
                throw new IOException("Destination '" + destDir + "' directory cannot be created");
            }
        }
        if (destDir.canWrite() == false) {
            throw new IOException("Destination '" + destDir + "' cannot be written to");
        }
        for (final File srcFile : srcFiles) {
            final File dstFile = new File(destDir, srcFile.getName());
            if (srcFile.isDirectory()) {
                copyDirectory(srcFile, dstFile);
            } else {
                copyFile(srcFile, dstFile);
            }
        }
    }

    public static void copyFile(final File srcFile, final File destFile) throws IOException {
        if (destFile.exists() && destFile.isDirectory()) {
            throw new IOException("Destination '" + destFile + "' exists but is a directory");
        }

        FileInputStream fis = null;
        FileOutputStream fos = null;
        FileChannel input = null;
        FileChannel output = null;
        try {
            fis = new FileInputStream(srcFile);
            fos = new FileOutputStream(destFile);
            input = fis.getChannel();
            output = fos.getChannel();
            final long size = input.size(); // TODO See IO-386
            long pos = 0;
            long count = 0;
            while (pos < size) {
                final long remain = size - pos;
                count = remain > FILE_COPY_BUFFER_SIZE ? FILE_COPY_BUFFER_SIZE : remain;
                final long bytesCopied = output.transferFrom(input, pos, count);
                if (bytesCopied == 0) { // IO-385 - can happen if file is truncated after caching the size
                    break; // ensure we don't loop forever
                }
                pos += bytesCopied;
            }
        } finally {
            if (output != null) {
                try {
                    output.close();
                } catch (Exception e) {
                }
            }
            if (fos != null) {
                try {
                    fos.close();
                } catch (Exception e) {
                }
            }
            if (input != null) {
                try {
                    input.close();
                } catch (Exception e) {
                }
            }
            if (fis != null) {
                try {
                    fis.close();
                } catch (Exception e) {
                }
            }
        }

        final long srcLen = srcFile.length(); // TODO See IO-386
        final long dstLen = destFile.length(); // TODO See IO-386
        if (srcLen != dstLen) {
            throw new IOException("Failed to copy full contents from '" + srcFile + "' to '" + destFile
                    + "' Expected length: " + srcLen + " Actual: " + dstLen);
        }
    }
}

Related

1. copyDirectory(File src, File target)
2. copyDirectory(File srcDir, File destDir)
3. copyDirectory(File srcDir, File destDir, boolean preserveFileDate)
4. copyDirectory(final File source, final File destination)
5. copyDirectory(final File sourceFile, final File targetDir)
6. copyDirectory(final Path source, final Path destination)
7. copyDirectory(final Path source, final Path destination, List excludes)
8. copyDirectory(Path source, ArrayList targets)
9. copyDirectory(String fromPath, String toPath)