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	/*
	* Copyright (c) 2007, 2011, Oracle and/or its affiliates. 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. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.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 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");
	}
	}

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