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Java example source code file (Demo.java)

This example Java source code file (Demo.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytebuffer, check, demo, directorystream, failed, filesystem, filevisitresult, ioexception, net, network, nio, override, path, runtimeexception, set, string, suppresswarnings, text, util

The Demo.java Java example source code

/*
 * Copyright (c) 2010 Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - 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
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * This source code is provided to illustrate the usage of a given feature
 * or technique and has been deliberately simplified. Additional steps
 * required for a production-quality application, such as security checks,
 * input validation and proper error handling, might not be present in
 * this sample code.
 */


import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.file.*;
import java.nio.file.spi.*;
import java.nio.file.attribute.*;
import java.net.*;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.*;

import static java.nio.file.StandardOpenOption.*;
import static java.nio.file.StandardCopyOption.*;
/*
 * ZipFileSystem usage demo
 *
 * java Demo action ZipfileName [...]
 *
 * @author Xueming Shen
 */

public class Demo {

    static enum Action {
        rename,          // <java Demo rename zipfile src dst>
                         // rename entry src to dst inside zipfile

        movein,          // <java Demo movein zipfile src dst>
                         // move an external src file into zipfile
                         // as entry dst

        moveout,         // <java Demo moveout zipfile src dst>
                         // move a zipfile entry src out to dst

        copy,            // <java Demo copy zipfile src dst>
                         // copy entry src to dst inside zipfile

        copyin,          // <java Demo copyin zipfile src dst>
                         // copy an external src file into zipfile
                         // as entry dst

        copyin_attrs,    // <java Demo copyin_attrs zipfile src dst>
                         // copy an external src file into zipfile
                         // as entry dst, with attributes (timestamp)

        copyout,         // <java Demo copyout zipfile src dst>
                         // copy zipfile entry src" out to file dst

        copyout_attrs,   // <java Demo copyout_attrs zipfile src dst>

        zzmove,          // <java Demo zzmove zfsrc zfdst path>
                         // move entry path/dir from zfsrc to zfdst

        zzcopy,          // <java Demo zzcopy zfsrc zfdst path>
                         // copy path from zipfile zfsrc to zipfile
                         // zfdst

        attrs,           // <java Demo attrs zipfile path>
                         // printout the attributes of entry path

        attrsspace,      // <java Demo attrsspace zipfile path>
                         // printout the storespace attrs of entry path

        setmtime,        // <java Demo setmtime zipfile "MM/dd/yy-HH:mm:ss" path...>
                         // set the lastModifiedTime of entry path

        setatime,        // <java Demo setatime zipfile "MM/dd/yy-HH:mm:ss" path...>
        setctime,        // <java Demo setctime zipfile "MM/dd/yy-HH:mm:ss" path...>

        lsdir,           // <java Demo lsdir zipfile dir>
                         // list dir's direct child files/dirs

        mkdir,           // <java Demo mkdir zipfile dir>

        mkdirs,          // <java Demo mkdirs zipfile dir>

        rmdirs,          // <java Demo rmdirs zipfile dir>

        list,            // <java Demo list zipfile [dir]>
                         // recursively list all entries of dir
                         // via DirectoryStream

        tlist,           // <java Demo tlist zipfile [dir]>
                         // list with buildDirTree=true

        vlist,           // <java Demo vlist zipfile [dir]>
                         // recursively verbose list all entries of
                         // dir via DirectoryStream

        walk,            // <java Demo walk zipfile [dir]>
                         // recursively walk all entries of dir
                         // via Files.walkFileTree

        twalk,           // <java Demo twalk zipfile [dir]>
                         // walk with buildDirTree=true

        extract,         // <java Demo extract zipfile file [...]>

        update,          // <java Demo extract zipfile file [...]>

        delete,          // <java Demo delete zipfile file [...]>

        add,             // <java Demo add zipfile file [...]>

        create,          // <java Demo create zipfile file [...]>
                         // create a new zipfile if it doesn't exit
                         // and then add the file(s) into it.

        attrs2,          // <java Demo attrs2 zipfile file [...]>
                         // test different ways to print attrs

        prof,
    }

    public static void main(String[] args) throws Throwable {
        FileSystemProvider provider = getZipFSProvider();
        if (provider == null) {
            System.err.println("ZIP filesystem provider is not installed");
            System.exit(1);
        }

        Action action = Action.valueOf(args[0]);
        Map<String, Object> env = env = new HashMap<>();
        if (action == Action.create)
            env.put("create", "true");
        try (FileSystem fs = provider.newFileSystem(Paths.get(args[1]), env)) {
            Path path, src, dst;
            switch (action) {
            case rename:
                src = fs.getPath(args[2]);
                dst = fs.getPath(args[3]);
                Files.move(src, dst);
                break;
            case moveout:
                src = fs.getPath(args[2]);
                dst = Paths.get(args[3]);
                Files.move(src, dst);
                break;
            case movein:
                src = Paths.get(args[2]);
                dst = fs.getPath(args[3]);
                Files.move(src, dst);
                break;
            case copy:
                src = fs.getPath(args[2]);
                dst = fs.getPath(args[3]);
                Files.copy(src, dst);
                break;
            case copyout:
                src = fs.getPath(args[2]);
                dst = Paths.get(args[3]);
                Files.copy(src, dst);
                break;
            case copyin:
                src = Paths.get(args[2]);
                dst = fs.getPath(args[3]);
                Files.copy(src, dst);
                break;
            case copyin_attrs:
                src = Paths.get(args[2]);
                dst = fs.getPath(args[3]);
                Files.copy(src, dst, COPY_ATTRIBUTES);
                break;
            case copyout_attrs:
                src = fs.getPath(args[2]);
                dst = Paths.get(args[3]);
                Files.copy(src, dst, COPY_ATTRIBUTES);
                break;
            case zzmove:
                try (FileSystem fs2 = provider.newFileSystem(Paths.get(args[2]), env)) {
                    z2zmove(fs, fs2, args[3]);
                }
                break;
            case zzcopy:
                try (FileSystem fs2 = provider.newFileSystem(Paths.get(args[2]), env)) {
                    z2zcopy(fs, fs2, args[3]);
                }
                break;
            case attrs:
                for (int i = 2; i < args.length; i++) {
                    path = fs.getPath(args[i]);
                    System.out.println(path);
                    System.out.println(
                        Files.readAttributes(path, BasicFileAttributes.class).toString());
                }
                break;
            case setmtime:
                DateFormat df = new SimpleDateFormat("MM/dd/yyyy-HH:mm:ss");
                Date newDatetime = df.parse(args[2]);
                for (int i = 3; i < args.length; i++) {
                    path = fs.getPath(args[i]);
                    Files.setAttribute(path, "lastModifiedTime",
                                       FileTime.fromMillis(newDatetime.getTime()));
                    System.out.println(
                        Files.readAttributes(path, BasicFileAttributes.class).toString());
                }
                break;
            case setctime:
                df = new SimpleDateFormat("MM/dd/yyyy-HH:mm:ss");
                newDatetime = df.parse(args[2]);
                for (int i = 3; i < args.length; i++) {
                    path = fs.getPath(args[i]);
                    Files.setAttribute(path, "creationTime",
                                       FileTime.fromMillis(newDatetime.getTime()));
                    System.out.println(
                        Files.readAttributes(path, BasicFileAttributes.class).toString());
                }
                break;
            case setatime:
                df = new SimpleDateFormat("MM/dd/yyyy-HH:mm:ss");
                newDatetime = df.parse(args[2]);
                for (int i = 3; i < args.length; i++) {
                    path = fs.getPath(args[i]);
                    Files.setAttribute(path, "lastAccessTime",
                                       FileTime.fromMillis(newDatetime.getTime()));
                    System.out.println(
                        Files.readAttributes(path, BasicFileAttributes.class).toString());
                }
                break;
            case attrsspace:
                path = fs.getPath("/");
                FileStore fstore = Files.getFileStore(path);
                System.out.printf("filestore[%s]%n", fstore.name());
                System.out.printf("    totalSpace: %d%n",
                                  (Long)fstore.getAttribute("totalSpace"));
                System.out.printf("   usableSpace: %d%n",
                                  (Long)fstore.getAttribute("usableSpace"));
                System.out.printf("  unallocSpace: %d%n",
                                  (Long)fstore.getAttribute("unallocatedSpace"));
                break;
            case list:
            case tlist:
                if (args.length < 3)
                    list(fs.getPath("/"), false);
                else
                    list(fs.getPath(args[2]), false);
                break;
            case vlist:
                if (args.length < 3)
                    list(fs.getPath("/"), true);
                else
                    list(fs.getPath(args[2]), true);
                break;
            case twalk:
            case walk:
                walk(fs.getPath((args.length > 2)? args[2] : "/"));
                break;
            case extract:
                if (args.length == 2) {
                     extract(fs, "/");
                } else {
                    for (int i = 2; i < args.length; i++) {
                        extract(fs, args[i]);
                    }
                }
                break;
            case delete:
                for (int i = 2; i < args.length; i++)
                    Files.delete(fs.getPath(args[i]));
                break;
            case create:
            case add:
            case update:
                for (int i = 2; i < args.length; i++) {
                    update(fs, args[i]);
                }
                break;
            case lsdir:
                path = fs.getPath(args[2]);
                final String fStr = (args.length > 3)?args[3]:"";
                try (DirectoryStream<Path> ds = Files.newDirectoryStream(path,
                    new DirectoryStream.Filter<Path>() {
                        @Override
                        public boolean accept(Path path) {
                            return path.toString().contains(fStr);
                        }
                    }))
                {
                    for (Path p : ds)
                        System.out.println(p);
                }
                break;
            case mkdir:
                Files.createDirectory(fs.getPath(args[2]));
                break;
            case mkdirs:
                mkdirs(fs.getPath(args[2]));
                break;
            case attrs2:
                for (int i = 2; i < args.length; i++) {
                    path = fs.getPath(args[i]);
                    System.out.printf("%n%s%n", path);
                    System.out.println("-------(1)---------");
                    System.out.println(
                        Files.readAttributes(path, BasicFileAttributes.class).toString());
                    System.out.println("-------(2)---------");
                    Map<String, Object> map = Files.readAttributes(path, "zip:*");
                    for (Map.Entry<String, Object> e : map.entrySet()) {
                        System.out.printf("    %s : %s%n", e.getKey(), e.getValue());
                    }
                    System.out.println("-------(3)---------");
                    map = Files.readAttributes(path, "size,lastModifiedTime,isDirectory");
                    for (Map.Entry<String, ?> e : map.entrySet()) {
                        System.out.printf("    %s : %s%n", e.getKey(), e.getValue());
                    }
                }
                break;
            case prof:
                list(fs.getPath("/"), false);
                while (true) {
                    Thread.sleep(10000);
                    //list(fs.getPath("/"), true);
                    System.out.println("sleeping...");
                }
            }
        } catch (Exception x) {
            x.printStackTrace();
        }
    }

    private static FileSystemProvider getZipFSProvider() {
        for (FileSystemProvider provider : FileSystemProvider.installedProviders()) {
            if ("jar".equals(provider.getScheme()))
                return provider;
        }
        return null;
    }

    @SuppressWarnings("unused")
    /**
     * Not used in demo, but included for demonstrational purposes.
     */
    private static byte[] getBytes(String name) {
        return name.getBytes();
    }

    @SuppressWarnings("unused")
    /**
     * Not used in demo, but included for demonstrational purposes.
     */
    private static String getString(byte[] name) {
        return new String(name);
    }

    private static void walk(Path path) throws IOException
    {
        Files.walkFileTree(
            path,
            new SimpleFileVisitor<Path>() {
                private int indent = 0;
                private void indent() {
                    int n = 0;
                    while (n++ < indent)
                        System.out.printf(" ");
                }

                @Override
                public FileVisitResult visitFile(Path file,
                                                 BasicFileAttributes attrs)
                {
                    indent();
                    System.out.printf("%s%n", file.getFileName().toString());
                    return FileVisitResult.CONTINUE;
                }

                @Override
                public FileVisitResult preVisitDirectory(Path dir,
                                                         BasicFileAttributes attrs)
                {
                    indent();
                    System.out.printf("[%s]%n", dir.toString());
                    indent += 2;
                    return FileVisitResult.CONTINUE;
                }

                @Override
                public FileVisitResult postVisitDirectory(Path dir,
                                                          IOException ioe)
                {
                    indent -= 2;
                    return FileVisitResult.CONTINUE;
                }
        });
    }

    private static void update(FileSystem fs, String path) throws Throwable{
        Path src = FileSystems.getDefault().getPath(path);
        if (Files.isDirectory(src)) {
            try (DirectoryStream<Path> ds = Files.newDirectoryStream(src)) {
                for (Path child : ds)
                    update(fs, child.toString());
            }
        } else {
            Path dst = fs.getPath(path);
            Path parent = dst.getParent();
            if (parent != null && Files.notExists(parent))
                mkdirs(parent);
            Files.copy(src, dst, REPLACE_EXISTING);
        }
    }

    private static void extract(FileSystem fs, String path) throws Throwable{
        Path src = fs.getPath(path);
        if (Files.isDirectory(src)) {
            try (DirectoryStream<Path> ds = Files.newDirectoryStream(src)) {
                for (Path child : ds)
                    extract(fs, child.toString());
            }
        } else {
            if (path.startsWith("/"))
                path = path.substring(1);
            Path dst = FileSystems.getDefault().getPath(path);
            Path parent = dst.getParent();
            if (Files.notExists(parent))
                mkdirs(parent);
            Files.copy(src, dst, REPLACE_EXISTING);
        }
    }

    // use DirectoryStream
    private static void z2zcopy(FileSystem src, FileSystem dst, String path)
        throws IOException
    {
        Path srcPath = src.getPath(path);
        Path dstPath = dst.getPath(path);

        if (Files.isDirectory(srcPath)) {
            if (!Files.exists(dstPath)) {
                try {
                    mkdirs(dstPath);
                } catch (FileAlreadyExistsException x) {}
            }
            try (DirectoryStream<Path> ds = Files.newDirectoryStream(srcPath)) {
                for (Path child : ds) {
                    z2zcopy(src, dst,
                            path + (path.endsWith("/")?"":"/") + child.getFileName());
                }
            }
        } else {
            //System.out.println("copying..." + path);
            Files.copy(srcPath, dstPath);
        }
    }

    // use TreeWalk to move
    private static void z2zmove(FileSystem src, FileSystem dst, String path)
        throws IOException
    {
        final Path srcPath = src.getPath(path).toAbsolutePath();
        final Path dstPath = dst.getPath(path).toAbsolutePath();

        Files.walkFileTree(srcPath, new SimpleFileVisitor<Path>() {

            @Override
            public FileVisitResult visitFile(Path file,
                                            BasicFileAttributes attrs)
            {
                Path dst = srcPath.relativize(file);
                dst = dstPath.resolve(dst);
                try {
                    Path parent = dstPath.getParent();
                    if (parent != null && Files.notExists(parent))
                        mkdirs(parent);
                    Files.move(file, dst);
                } catch (IOException x) {
                    x.printStackTrace();
                }
                return FileVisitResult.CONTINUE;
            }

            @Override
            public FileVisitResult preVisitDirectory(Path dir,
                                                     BasicFileAttributes attrs)
            {
                Path dst = srcPath.relativize(dir);
                dst = dstPath.resolve(dst);
                try {

                    if (Files.notExists(dst))
                        mkdirs(dst);
                } catch (IOException x) {
                    x.printStackTrace();
                }
                return FileVisitResult.CONTINUE;
            }

            @Override
            public FileVisitResult postVisitDirectory(Path dir,
                                                      IOException ioe)
                throws IOException
            {
                try {
                    Files.delete(dir);
                } catch (IOException x) {
                    //x.printStackTrace();
                }
                return FileVisitResult.CONTINUE;
            }
        });

    }

    private static void mkdirs(Path path) throws IOException {
        path = path.toAbsolutePath();
        Path parent = path.getParent();
        if (parent != null) {
            if (Files.notExists(parent))
                mkdirs(parent);
        }
        Files.createDirectory(path);
    }

    @SuppressWarnings("unused")
    /**
     * Not used in demo, but included for demonstrational purposes.
     */
    private static void rmdirs(Path path) throws IOException {
        while (path != null && path.getNameCount() != 0) {
            Files.delete(path);
            path = path.getParent();
        }
    }

    private static void list(Path path, boolean verbose ) throws IOException {
        if (!"/".equals(path.toString())) {
           System.out.printf("  %s%n", path.toString());
           if (verbose)
                System.out.println(Files.readAttributes(path, BasicFileAttributes.class).toString());
        }
        if (Files.notExists(path))
            return;
        if (Files.isDirectory(path)) {
            try (DirectoryStream<Path> ds = Files.newDirectoryStream(path)) {
                for (Path child : ds)
                    list(child, verbose);
            }
        }
    }

    @SuppressWarnings("unused")
    /**
     * Checks that the content of two paths are equal.
     * Not used in demo, but included for demonstrational purposes.
     */
    private static void checkEqual(Path src, Path dst) throws IOException
    {
        //System.out.printf("checking <%s> vs <%s>...%n",
        //                  src.toString(), dst.toString());

        //streams
        byte[] bufSrc = new byte[8192];
        byte[] bufDst = new byte[8192];
        try (InputStream isSrc = Files.newInputStream(src);
             InputStream isDst = Files.newInputStream(dst))
        {
            int nSrc = 0;
            while ((nSrc = isSrc.read(bufSrc)) != -1) {
                int nDst = 0;
                while (nDst < nSrc) {
                    int n = isDst.read(bufDst, nDst, nSrc - nDst);
                    if (n == -1) {
                        System.out.printf("checking <%s> vs <%s>...%n",
                                          src.toString(), dst.toString());
                        throw new RuntimeException("CHECK FAILED!");
                    }
                    nDst += n;
                }
                while (--nSrc >= 0) {
                    if (bufSrc[nSrc] != bufDst[nSrc]) {
                        System.out.printf("checking <%s> vs <%s>...%n",
                                          src.toString(), dst.toString());
                        throw new RuntimeException("CHECK FAILED!");
                    }
                    nSrc--;
                }
            }
        }

        // channels

        try (SeekableByteChannel chSrc = Files.newByteChannel(src);
             SeekableByteChannel chDst = Files.newByteChannel(dst))
        {
            if (chSrc.size() != chDst.size()) {
                System.out.printf("src[%s].size=%d, dst[%s].size=%d%n",
                                  chSrc.toString(), chSrc.size(),
                                  chDst.toString(), chDst.size());
                throw new RuntimeException("CHECK FAILED!");
            }
            ByteBuffer bbSrc = ByteBuffer.allocate(8192);
            ByteBuffer bbDst = ByteBuffer.allocate(8192);

            int nSrc = 0;
            while ((nSrc = chSrc.read(bbSrc)) != -1) {
                int nDst = chDst.read(bbDst);
                if (nSrc != nDst) {
                    System.out.printf("checking <%s> vs <%s>...%n",
                                      src.toString(), dst.toString());
                    throw new RuntimeException("CHECK FAILED!");
                }
                while (--nSrc >= 0) {
                    if (bbSrc.get(nSrc) != bbDst.get(nSrc)) {
                        System.out.printf("checking <%s> vs <%s>...%n",
                                          src.toString(), dst.toString());
                        throw new RuntimeException("CHECK FAILED!");
                    }
                    nSrc--;
                }
                bbSrc.flip();
                bbDst.flip();
            }
        } catch (IOException x) {
            x.printStackTrace();
        }
    }

    private static void fchCopy(Path src, Path dst) throws IOException
    {
        Set<OpenOption> read = new HashSet<>();
        read.add(READ);
        Set<OpenOption> openwrite = new HashSet<>();
        openwrite.add(CREATE_NEW);
        openwrite.add(WRITE);

        try (FileChannel srcFc = src.getFileSystem().provider().newFileChannel(src, read);
             FileChannel dstFc = dst.getFileSystem().provider().newFileChannel(dst, openwrite))
        {
            ByteBuffer bb = ByteBuffer.allocate(8192);
            while (srcFc.read(bb) >= 0) {
                bb.flip();
                dstFc.write(bb);
                bb.clear();
            }
        }
    }

    private static void chCopy(Path src, Path dst) throws IOException
    {
        Set<OpenOption> read = new HashSet<>();
        read.add(READ);
        Set<OpenOption> openwrite = new HashSet<>();
        openwrite.add(CREATE_NEW);
        openwrite.add(WRITE);

        try (SeekableByteChannel srcCh = Files.newByteChannel(src, read);
             SeekableByteChannel dstCh = Files.newByteChannel(dst, openwrite))
        {
            ByteBuffer bb = ByteBuffer.allocate(8192);
            while (srcCh.read(bb) >= 0) {
                bb.flip();
                dstCh.write(bb);
                bb.clear();
            }
        }
    }

    private static void streamCopy(Path src, Path dst) throws IOException
    {
        byte[] buf = new byte[8192];
        try (InputStream isSrc = Files.newInputStream(src);
             OutputStream osDst = Files.newOutputStream(dst))
        {
            int n = 0;
            while ((n = isSrc.read(buf)) != -1) {
                osDst.write(buf, 0, n);
            }
        }
    }
}

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