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 * published by the Free Software Foundation.  Oracle designates this

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

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

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 * 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

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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 final class Paths {

    private Paths() { }

    /**

     * Converts a path string, or a sequence of strings that when joined form

     * a path string, to a {@code Path}. If {@code more} does not specify any

     * elements then the value of the {@code first} parameter is the path string

     * to convert. If {@code more} specifies one or more elements then each

     * non-empty string, including {@code first}, is considered to be a sequence

     * of name elements (see {@link Path}) and is joined to form a path string.

     * The details as to how the Strings are joined is provider specific but

     * typically they will be joined using the {@link FileSystem#getSeparator

     * name-separator} as the separator. For example, if the name separator is

     * "{@code /}" and {@code getPath("/foo","bar","gus")} is invoked, then the

     * path string {@code "/foo/bar/gus"} is converted to a {@code Path}.

     * A {@code Path} representing an empty path is returned if {@code first}

     * is the empty string and {@code more} does not contain any non-empty

     * strings.

     *

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

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

     * FileSystem}.

     *

     * <p> Note that while this method is very convenient, using it will imply

     * an assumed reference to the default {@code FileSystem} and limit the

     * utility of the calling code. Hence it should not be used in library code

     * intended for flexible reuse. A more flexible alternative is to use an

     * existing {@code Path} instance as an anchor, such as:

     * <pre>

     *     Path dir = ...

     *     Path path = dir.resolve("file");

     * </pre>

     *

     * @param   first

     *          the path string or initial part of the path string

     * @param   more

     *          additional strings to be joined to form the path string

     *

     * @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 first, String... more) {

        return FileSystems.getDefault().getPath(first, more);

    }

    /**

     * 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

     *          The file system, identified by the URI, does not exist and

     *          cannot be created automatically, 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");

    }

}