将文件复制到保留文件日期的目录。
/* N o w J a v a . c o m - 时代Java 提供 */ /* * 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 * * http://www.apache.org/licenses/LICENSE-2.0 * * 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.Closeable; import java.io.File; import java.io.FileFilter; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.nio.channels.FileChannel; import java.util.ArrayList; import java.util.List; public class Main{ public static void main(String[] argv) throws Exception{ File srcFile = new File("Main.java"); File destDir = new File("Main.java"); copyFileToDirectory(srcFile,destDir); } /** * The file copy buffer size (30 MB) */ /** 来 自 n o w j a v a . c o m - 时 代 Java **/ private static final long FILE_COPY_BUFFER_SIZE = ONE_MB * 30; /** * Copies a file to a directory preserving the file date. * <p> * This method copies the contents of the specified source file * to a file of the same name in the specified destination directory. * The destination directory is created if it does not exist. * If the destination file exists, then this method will overwrite it. * <p> * <strong>Note:</strong> This method tries to preserve the file's last * modified date/times using {@link File#setLastModified(long)}, however * it is not guaranteed that the operation will succeed. * If the modification operation fails, no indication is provided. * * @param srcFile an existing file to copy, must not be <code>null</code> * @param destDir the directory to place the copy in, must not be <code>null</code> * * @throws NullPointerException if source or destination is null * @throws IOException if source or destination is invalid * @throws IOException if an IO error occurs during copying * @see #copyFile(File, File, boolean) */ public static void copyFileToDirectory(File srcFile, File destDir) throws IOException { copyFileToDirectory(srcFile, destDir, true); } /** * Copies a file to a directory optionally preserving the file date. * <p> * This method copies the contents of the specified source file * to a file of the same name in the specified destination directory. * The destination directory is created if it does not exist. * If the destination file exists, then this method will overwrite it. * <p> * <strong>Note:</strong> Setting <code>preserveFileDate</code> to * <code>true</code> tries to preserve the file's last modified * date/times using {@link File#setLastModified(long)}, however it is * not guaranteed that the operation will succeed. * If the modification operation fails, no indication is provided. * * @param srcFile an existing file to copy, must not be <code>null</code> * @param destDir the directory to place the copy in, must not be <code>null</code> * @param preserveFileDate true if the file date of the copy * should be the same as the original * * @throws NullPointerException if source or destination is <code>null</code> * @throws IOException if source or destination is invalid * @throws IOException if an IO error occurs during copying * @see #copyFile(File, File, boolean) * @since Commons IO 1.3 */ private static void copyFileToDirectory(File srcFile, File destDir, boolean preserveFileDate) throws IOException { if (destDir == null) { throw new NullPointerException("Destination must not be null"); } if (destDir.exists() && destDir.isDirectory() == false) { throw new IllegalArgumentException("Destination '" + destDir + "' is not a directory"); } File destFile = new File(destDir, srcFile.getName()); copyFile(srcFile, destFile, preserveFileDate); } /** * Copies a file to a new location preserving the file date. * <p> * This method copies the contents of the specified source file to the * specified destination file. The directory holding the destination file is * created if it does not exist. If the destination file exists, then this * method will overwrite it. * <p> * <strong>Note:</strong> This method tries to preserve the file's last * modified date/times using {@link File#setLastModified(long)}, however * it is not guaranteed that the operation will succeed. * If the modification operation fails, no indication is provided. * * @param srcFile an existing file to copy, must not be <code>null</code> * @param destFile the new file, must not be <code>null</code> * * @throws NullPointerException if source or destination is <code>null</code> * @throws IOException if source or destination is invalid * @throws IOException if an IO error occurs during copying * @see #copyFileToDirectory(File, File) */ public static void copyFile(File srcFile, File destFile) throws IOException { copyFile(srcFile, destFile, true); } /** * Copies a file to a new location. * <p> * This method copies the contents of the specified source file * to the specified destination file. * The directory holding the destination file is created if it does not exist. * If the destination file exists, then this method will overwrite it. * <p> * <strong>Note:</strong> Setting <code>preserveFileDate</code> to * <code>true</code> tries to preserve the file's last modified * date/times using {@link File#setLastModified(long)}, however it is * not guaranteed that the operation will succeed. * If the modification operation fails, no indication is provided. * * @param srcFile an existing file to copy, must not be <code>null</code> * @param destFile the new file, must not be <code>null</code> * @param preserveFileDate true if the file date of the copy * should be the same as the original * * @throws NullPointerException if source or destination is <code>null</code> * @throws IOException if source or destination is invalid * @throws IOException if an IO error occurs during copying * @see #copyFileToDirectory(File, File, boolean) */ private static void copyFile(File srcFile, File destFile, boolean preserveFileDate) throws IOException { if (srcFile == null) { throw new NullPointerException("Source must not be null"); } if (destFile == null) { throw new NullPointerException("Destination must not be null"); } if (srcFile.exists() == false) { throw new FileNotFoundException("Source '" + srcFile + "' does not exist"); } if (srcFile.isDirectory()) { throw new IOException("Source '" + srcFile + "' exists but is a directory"); } if (srcFile.getCanonicalPath().equals(destFile.getCanonicalPath())) { throw new IOException("Source '" + srcFile + "' and destination '" + destFile + "' are the same"); } File parentFile = destFile.getParentFile(); if (parentFile != null) { if (!parentFile.mkdirs() && !parentFile.isDirectory()) { throw new IOException("Destination '" + parentFile + "' directory cannot be created"); } } if (destFile.exists() && destFile.canWrite() == false) { throw new IOException("Destination '" + destFile + "' exists but is read-only"); } doCopyFile(srcFile, destFile, preserveFileDate); } /** * Internal copy file method. * * @param srcFile the validated source file, must not be <code>null</code> * @param destFile the validated destination file, must not be <code>null</code> * @param preserveFileDate whether to preserve the file date * @throws IOException if an error occurs */ private static void doCopyFile(File srcFile, File destFile, boolean preserveFileDate) 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(); long size = input.size(); long pos = 0; long count = 0; while (pos < size) { count = (size - pos) > FILE_COPY_BUFFER_SIZE ? FILE_COPY_BUFFER_SIZE : (size - pos); pos += output.transferFrom(input, pos, count); } } finally { closeQuietly(output); closeQuietly(fos); closeQuietly(input); closeQuietly(fis); } if (srcFile.length() != destFile.length()) { throw new IOException("Failed to copy full contents from '" + srcFile + "' to '" + destFile + "'"); } if (preserveFileDate) { destFile.setLastModified(srcFile.lastModified()); } }