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 *

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 * modification, are permitted provided that the following conditions

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 *

 *   - 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 Oracle 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

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 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

import java.nio.file.*;

import static java.nio.file.StandardCopyOption.*;

import java.nio.file.attribute.*;

import static java.nio.file.FileVisitResult.*;

import java.io.IOException;

import java.util.*;

/**

 * Sample code that copies files in a similar manner to the cp(1) program.

 */

public class Copy {

    /**

     * Returns {@code true} if okay to overwrite a  file ("cp -i")

     */

    static boolean okayToOverwrite(Path file) {

        String answer = System.console().readLine("overwrite %s (yes/no)? ", file);

        return (answer.equalsIgnoreCase("y") || answer.equalsIgnoreCase("yes"));

    }

    /**

     * Copy source file to target location. If {@code prompt} is true then

     * prompt user to overwrite target if it exists. The {@code preserve}

     * parameter determines if file attributes should be copied/preserved.

     */

    static void copyFile(Path source, Path target, boolean prompt, boolean preserve) {

        CopyOption[] options = (preserve) ?

            new CopyOption[] { COPY_ATTRIBUTES, REPLACE_EXISTING } :

            new CopyOption[] { REPLACE_EXISTING };

        if (!prompt || Files.notExists(target) || okayToOverwrite(target)) {

            try {

                Files.copy(source, target, options);

            } catch (IOException x) {

                System.err.format("Unable to copy: %s: %s%n", source, x);

            }

        }

    }

    /**

     * A {@code FileVisitor} that copies a file-tree ("cp -r")

     */

    static class TreeCopier implements FileVisitor<Path> {

        private final Path source;

        private final Path target;

        private final boolean prompt;

        private final boolean preserve;

        TreeCopier(Path source, Path target, boolean prompt, boolean preserve) {

            this.source = source;

            this.target = target;

            this.prompt = prompt;

            this.preserve = preserve;

        }

        @Override

        public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {

            // before visiting entries in a directory we copy the directory

            // (okay if directory already exists).

            CopyOption[] options = (preserve) ?

                new CopyOption[] { COPY_ATTRIBUTES } : new CopyOption[0];

            Path newdir = target.resolve(source.relativize(dir));

            try {

                Files.copy(dir, newdir, options);

            } catch (FileAlreadyExistsException x) {

                // ignore

            } catch (IOException x) {

                System.err.format("Unable to create: %s: %s%n", newdir, x);

                return SKIP_SUBTREE;

            }

            return CONTINUE;

        }

        @Override

        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {

            copyFile(file, target.resolve(source.relativize(file)),

                     prompt, preserve);

            return CONTINUE;

        }

        @Override

        public FileVisitResult postVisitDirectory(Path dir, IOException exc) {

            // fix up modification time of directory when done

            if (exc == null && preserve) {

                Path newdir = target.resolve(source.relativize(dir));

                try {

                    FileTime time = Files.getLastModifiedTime(dir);

                    Files.setLastModifiedTime(newdir, time);

                } catch (IOException x) {

                    System.err.format("Unable to copy all attributes to: %s: %s%n", newdir, x);

                }

            }

            return CONTINUE;

        }

        @Override

        public FileVisitResult visitFileFailed(Path file, IOException exc) {

            if (exc instanceof FileSystemLoopException) {

                System.err.println("cycle detected: " + file);

            } else {

                System.err.format("Unable to copy: %s: %s%n", file, exc);

            }

            return CONTINUE;

        }

    }

    static void usage() {

        System.err.println("java Copy [-ip] source... target");

        System.err.println("java Copy -r [-ip] source-dir... target");

        System.exit(-1);

    }

    public static void main(String[] args) throws IOException {

        boolean recursive = false;

        boolean prompt = false;

        boolean preserve = false;

        // process options

        int argi = 0;

        while (argi < args.length) {

            String arg = args[argi];

            if (!arg.startsWith("-"))

                break;

            if (arg.length() < 2)

                usage();

            for (int i=1; i<arg.length(); i++) {

                char c = arg.charAt(i);

                switch (c) {

                    case 'r' : recursive = true; break;

                    case 'i' : prompt = true; break;

                    case 'p' : preserve = true; break;

                    default : usage();

                }

            }

            argi++;

        }

        // remaining arguments are the source files(s) and the target location

        int remaining = args.length - argi;

        if (remaining < 2)

            usage();

        Path[] source = new Path[remaining-1];

        int i=0;

        while (remaining > 1) {

            source[i++] = Paths.get(args[argi++]);

            remaining--;

        }

        Path target = Paths.get(args[argi]);

        // check if target is a directory

        boolean isDir = Files.isDirectory(target);

        // copy each source file/directory to target

        for (i=0; i<source.length; i++) {

            Path dest = (isDir) ? target.resolve(source[i].getFileName()) : target;

            if (recursive) {

                // follow links when copying files

                EnumSet<FileVisitOption> opts = EnumSet.of(FileVisitOption.FOLLOW_LINKS);

                TreeCopier tc = new TreeCopier(source[i], dest, prompt, preserve);

                Files.walkFileTree(source[i], opts, Integer.MAX_VALUE, tc);

            } else {

                // not recursive so source must not be a directory

                if (Files.isDirectory(source[i])) {

                    System.err.format("%s: is a directory%n", source[i]);

                    continue;

                }

                copyFile(source[i], dest, prompt, preserve);

            }

        }

    }

}