Java FileChannel Copy copyFile(final File srcFile, final File destFile)

Description

copy File

License

Apache License

Declaration

public static void copyFile(final File srcFile, final File destFile) throws IOException 

Method Source Code

//package com.java2s;
/**/*from  www  .j  a v  a 2  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 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. copyFile(final File in, final File out)
2. copyFile(final File input, final File output)
3. copyFile(final File src, final File dest)
4. copyFile(final File src, final File dst)
5. copyFile(final File srcFile, final File destFile)
6. copyFile(final String src, final String dest)
7. copyFile(final String src, final String dst)
8. copyFile(InputStream is, OutputStream os)
9. copyFile(java.io.File fromFile, java.io.File toFile)