Java example source code file (ZipFileSystemProvider.java)

This example Java source code file (ZipFileSystemProvider.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

fileattribute, illegalargumentexception, ioexception, linkoption, map, net, network, openoption, override, path, set, string, threading, threads, unsupportedoperationexception, uri, util, zip, zipfilesystem, zippath

The ZipFileSystemProvider.java Java example source code

/*
 * Copyright (c) 2009, 2012, 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.
 */


package com.sun.nio.zipfs;

import java.io.*;
import java.nio.channels.*;
import java.nio.file.*;
import java.nio.file.DirectoryStream.Filter;
import java.nio.file.attribute.*;
import java.nio.file.spi.FileSystemProvider;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.zip.ZipError;
import java.util.concurrent.ExecutorService;

/*
 *
 * @author  Xueming Shen, Rajendra Gutupalli, Jaya Hangal
 */

public class ZipFileSystemProvider extends FileSystemProvider {


    private final Map<Path, ZipFileSystem> filesystems = new HashMap<>();

    public ZipFileSystemProvider() {}

    @Override
    public String getScheme() {
        return "jar";
    }

    protected Path uriToPath(URI uri) {
        String scheme = uri.getScheme();
        if ((scheme == null) || !scheme.equalsIgnoreCase(getScheme())) {
            throw new IllegalArgumentException("URI scheme is not '" + getScheme() + "'");
        }
        try {
            // only support legacy JAR URL syntax  jar:{uri}!/{entry} for now
            String spec = uri.getRawSchemeSpecificPart();
            int sep = spec.indexOf("!/");
            if (sep != -1)
                spec = spec.substring(0, sep);
            return Paths.get(new URI(spec)).toAbsolutePath();
        } catch (URISyntaxException e) {
            throw new IllegalArgumentException(e.getMessage(), e);
        }
    }

    private boolean ensureFile(Path path) {
        try {
            BasicFileAttributes attrs =
                Files.readAttributes(path, BasicFileAttributes.class);
            if (!attrs.isRegularFile())
                throw new UnsupportedOperationException();
            return true;
        } catch (IOException ioe) {
            return false;
        }
    }

    @Override
    public FileSystem newFileSystem(URI uri, Map<String, ?> env)
        throws IOException
    {
        Path path = uriToPath(uri);
        synchronized(filesystems) {
            Path realPath = null;
            if (ensureFile(path)) {
                realPath = path.toRealPath();
                if (filesystems.containsKey(realPath))
                    throw new FileSystemAlreadyExistsException();
            }
            ZipFileSystem zipfs = null;
            try {
                zipfs = new ZipFileSystem(this, path, env);
            } catch (ZipError ze) {
                String pname = path.toString();
                if (pname.endsWith(".zip") || pname.endsWith(".jar"))
                    throw ze;
                // assume NOT a zip/jar file
                throw new UnsupportedOperationException();
            }
            filesystems.put(realPath, zipfs);
            return zipfs;
        }
    }

    @Override
    public FileSystem newFileSystem(Path path, Map<String, ?> env)
        throws IOException
    {
        if (path.getFileSystem() != FileSystems.getDefault()) {
            throw new UnsupportedOperationException();
        }
        ensureFile(path);
        try {
            return new ZipFileSystem(this, path, env);
        } catch (ZipError ze) {
            String pname = path.toString();
            if (pname.endsWith(".zip") || pname.endsWith(".jar"))
                throw ze;
            throw new UnsupportedOperationException();
        }
    }

    @Override
    public Path getPath(URI uri) {

        String spec = uri.getSchemeSpecificPart();
        int sep = spec.indexOf("!/");
        if (sep == -1)
            throw new IllegalArgumentException("URI: "
                + uri
                + " does not contain path info ex. jar:file:/c:/foo.zip!/BAR");
        return getFileSystem(uri).getPath(spec.substring(sep + 1));
    }


    @Override
    public FileSystem getFileSystem(URI uri) {
        synchronized (filesystems) {
            ZipFileSystem zipfs = null;
            try {
                zipfs = filesystems.get(uriToPath(uri).toRealPath());
            } catch (IOException x) {
                // ignore the ioe from toRealPath(), return FSNFE
            }
            if (zipfs == null)
                throw new FileSystemNotFoundException();
            return zipfs;
        }
    }

    // Checks that the given file is a UnixPath
    static final ZipPath toZipPath(Path path) {
        if (path == null)
            throw new NullPointerException();
        if (!(path instanceof ZipPath))
            throw new ProviderMismatchException();
        return (ZipPath)path;
    }

    @Override
    public void checkAccess(Path path, AccessMode... modes) throws IOException {
        toZipPath(path).checkAccess(modes);
    }

    @Override
    public void copy(Path src, Path target, CopyOption... options)
        throws IOException
    {
        toZipPath(src).copy(toZipPath(target), options);
    }

    @Override
    public void createDirectory(Path path, FileAttribute<?>... attrs)
        throws IOException
    {
        toZipPath(path).createDirectory(attrs);
    }

    @Override
    public final void delete(Path path) throws IOException {
        toZipPath(path).delete();
    }

    @Override
    @SuppressWarnings("unchecked")
    public <V extends FileAttributeView> V
        getFileAttributeView(Path path, Class<V> type, LinkOption... options)
    {
        return ZipFileAttributeView.get(toZipPath(path), type);
    }

    @Override
    public FileStore getFileStore(Path path) throws IOException {
        return toZipPath(path).getFileStore();
    }

    @Override
    public boolean isHidden(Path path) {
        return toZipPath(path).isHidden();
    }

    @Override
    public boolean isSameFile(Path path, Path other) throws IOException {
        return toZipPath(path).isSameFile(other);
    }

    @Override
    public void move(Path src, Path target, CopyOption... options)
        throws IOException
    {
        toZipPath(src).move(toZipPath(target), options);
    }

    @Override
    public AsynchronousFileChannel newAsynchronousFileChannel(Path path,
            Set<? extends OpenOption> options,
            ExecutorService exec,
            FileAttribute<?>... attrs)
            throws IOException
    {
        throw new UnsupportedOperationException();
    }

    @Override
    public SeekableByteChannel newByteChannel(Path path,
                                              Set<? extends OpenOption> options,
                                              FileAttribute<?>... attrs)
        throws IOException
    {
        return toZipPath(path).newByteChannel(options, attrs);
    }

    @Override
    public DirectoryStream<Path> newDirectoryStream(
        Path path, Filter<? super Path> filter) throws IOException
    {
        return toZipPath(path).newDirectoryStream(filter);
    }

    @Override
    public FileChannel newFileChannel(Path path,
                                      Set<? extends OpenOption> options,
                                      FileAttribute<?>... attrs)
        throws IOException
    {
        return toZipPath(path).newFileChannel(options, attrs);
    }

    @Override
    public InputStream newInputStream(Path path, OpenOption... options)
        throws IOException
    {
        return toZipPath(path).newInputStream(options);
    }

    @Override
    public OutputStream newOutputStream(Path path, OpenOption... options)
        throws IOException
    {
        return toZipPath(path).newOutputStream(options);
    }

    @Override
    public <A extends BasicFileAttributes> A
        readAttributes(Path path, Class<A> type, LinkOption... options)
        throws IOException
    {
        if (type == BasicFileAttributes.class || type == ZipFileAttributes.class)
            return (A)toZipPath(path).getAttributes();
        return null;
    }

    @Override
    public Map<String, Object>
        readAttributes(Path path, String attribute, LinkOption... options)
        throws IOException
    {
        return toZipPath(path).readAttributes(attribute, options);
    }

    @Override
    public Path readSymbolicLink(Path link) throws IOException {
        throw new UnsupportedOperationException("Not supported.");
    }

    @Override
    public void setAttribute(Path path, String attribute,
                             Object value, LinkOption... options)
        throws IOException
    {
        toZipPath(path).setAttribute(attribute, value, options);
    }

    //////////////////////////////////////////////////////////////
    void removeFileSystem(Path zfpath, ZipFileSystem zfs) throws IOException {
        synchronized (filesystems) {
            zfpath = zfpath.toRealPath();
            if (filesystems.get(zfpath) == zfs)
                filesystems.remove(zfpath);
        }
    }
}