/*

 * Copyright 2007-2009 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.nio.file;

import java.nio.file.spi.FileSystemProvider;

import java.net.URI;

/**

 * This class consists exclusively of static methods that return a {@link Path}

 * by converting a path string or {@link URI}.

 *

 * @since 1.7

 */

public class Paths {

    private Paths() { }

    /**

     * Constructs a {@code Path} by converting the given path string.

     *

     * <p> The {@code Path} is obtained by invoking the {@link FileSystem#getPath

     * getPath} method of the {@link FileSystems#getDefault default} {@link

     * FileSystem}.

     *

     * @param   path

     *          The path string to convert

     *

     * @return  The resulting {@code Path}

     *

     * @throws  InvalidPathException

     *          If the path string cannot be converted to a {@code Path}

     *

     * @see FileSystem#getPath

     */

    public static Path get(String path) {

        return FileSystems.getDefault().getPath(path);

    }

    /**

     * Converts the given URI to a {@link Path} object.

     *

     * <p> This method iterates over the {@link FileSystemProvider#installedProviders()

     * installed} providers to locate the provider that is identified by the

     * URI {@link URI#getScheme scheme} of the given URI. URI schemes are

     * compared without regard to case. If the provider is found then its {@link

     * FileSystemProvider#getPath getPath} method is invoked to convert the

     * URI.

     *

     * <p> In the case of the default provider, identified by the URI scheme

     * "file", the given URI has a non-empty path component, and undefined query

     * and fragment components. Whether the authority component may be present

     * is platform specific. The returned {@code Path} is associated with the

     * {@link FileSystems#getDefault default} file system.

     *

     * <p> The default provider provides a similar <em>round-trip</em> guarantee

     * to the {@link java.io.File} class. For a given {@code Path} <i>p</i> it

     * is guaranteed that

     * <blockquote><tt>

     * Paths.get(</tt><i>p</i><tt>.{@link Path#toUri() toUri}()).equals(</tt>

     * <i>p</i><tt>.{@link Path#toAbsolutePath() toAbsolutePath}())</tt>

     * </blockquote>

     * so long as the original {@code Path}, the {@code URI}, and the new {@code

     * Path} are all created in (possibly different invocations of) the same

     * Java virtual machine. Whether other providers make any guarantees is

     * provider specific and therefore unspecified.

     *

     * @param   uri

     *          The URI to convert

     *

     * @return  The resulting {@code Path}

     *

     * @throws  IllegalArgumentException

     *          If preconditions on the {@code uri} parameter do not hold. The

     *          format of the URI is provider specific.

     * @throws  FileSystemNotFoundException

     *          If the file system identified by the URI does not exist or the

     *          provider identified by the URI's scheme component is not installed

     * @throws  SecurityException

     *          If a security manager is installed and it denies an unspecified

     *          permission to access the file system

     */

    public static Path get(URI uri) {

        String scheme =  uri.getScheme();

        if (scheme == null)

            throw new IllegalArgumentException("Missing scheme");

        // check for default provider to avoid loading of installed providers

        if (scheme.equalsIgnoreCase("file"))

            return FileSystems.getDefault().provider().getPath(uri);

        // try to find provider

        for (FileSystemProvider provider: FileSystemProvider.installedProviders()) {

            if (provider.getScheme().equalsIgnoreCase(scheme)) {

                return provider.getPath(uri);

            }

        }

        throw new FileSystemNotFoundException("Provider \"" + scheme + "\" not installed");

    }

}