/*

 * Copyright (c) 2005, 2016, 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

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 * questions.

 */

package javax.tools;

import java.io.Closeable;

import java.io.Flushable;

import java.io.IOException;

import java.util.Iterator;

import java.util.ServiceLoader;

import java.util.Set;

import static javax.tools.JavaFileObject.Kind;

/**

 * File manager for tools operating on Java™ programming language

 * source and class files.  In this context, <em>file</em> means an

 * abstraction of regular files and other sources of data.

 *

 * <p>When constructing new JavaFileObjects, the file manager must

 * determine where to create them.  For example, if a file manager

 * manages regular files on a file system, it would most likely have a

 * current/working directory to use as default location when creating

 * or finding files.  A number of hints can be provided to a file

 * manager as to where to create files.  Any file manager might choose

 * to ignore these hints.

 *

 * <p>Some methods in this interface use class names.  Such class

 * names must be given in the Java Virtual Machine internal form of

 * fully qualified class and interface names.  For convenience '.'

 * and '/' are interchangeable.  The internal form is defined in

 * chapter four of

 * <cite>The Java&trade; Virtual Machine Specification</cite>.

 * <blockquote><p>

 *   <i>Discussion:</i> this means that the names

 *   "java/lang.package-info", "java/lang/package-info",

 *   "java.lang.package-info", are valid and equivalent.  Compare to

 *   binary name as defined in

 *   <cite>The Java&trade; Language Specification</cite>,

 *   section 13.1 "The Form of a Binary".

 * </p></blockquote>

 *

 * <p>The case of names is significant.  All names should be treated

 * as case-sensitive.  For example, some file systems have

 * case-insensitive, case-aware file names.  File objects representing

 * such files should take care to preserve case by using {@link

 * java.io.File#getCanonicalFile} or similar means.  If the system is

 * not case-aware, file objects must use other means to preserve case.

 *

 * <p><em><a name="relative_name">Relative names</a>:</em> some

 * methods in this interface use relative names.  A relative name is a

 * non-null, non-empty sequence of path segments separated by '/'.

 * '.' or '..'  are invalid path segments.  A valid relative name must

 * match the "path-rootless" rule of <a

 * href="http://www.ietf.org/rfc/rfc3986.txt">RFC&nbsp;3986</a>,

 * section 3.3.  Informally, this should be true:

 *

 * <!-- URI.create(relativeName).normalize().getPath().equals(relativeName) -->

 * <pre>  URI.{@linkplain java.net.URI#create create}(relativeName).{@linkplain java.net.URI#normalize normalize}().{@linkplain java.net.URI#getPath getPath}().equals(relativeName)</pre>

 *

 * <p>All methods in this interface might throw a SecurityException.

 *

 * <p>An object of this interface is not required to support

 * multi-threaded access, that is, be synchronized.  However, it must

 * support concurrent access to different file objects created by this

 * object.

 *

 * <p><em>Implementation note:</em> a consequence of this requirement

 * is that a trivial implementation of output to a {@linkplain

 * java.util.jar.JarOutputStream} is not a sufficient implementation.

 * That is, rather than creating a JavaFileObject that returns the

 * JarOutputStream directly, the contents must be cached until closed

 * and then written to the JarOutputStream.

 *

 * <p>Unless explicitly allowed, all methods in this interface might

 * throw a NullPointerException if given a {@code null} argument.

 *

 * @author Peter von der Ahé

 * @author Jonathan Gibbons

 * @see JavaFileObject

 * @see FileObject

 * @since 1.6

 */

public interface JavaFileManager extends Closeable, Flushable, OptionChecker {

    /**

     * Interface for locations of file objects.  Used by file managers

     * to determine where to place or search for file objects.

     */

    interface Location {

        /**

         * Returns the name of this location.

         *

         * @return a name

         */

        String getName();

        /**

         * Determines if this is an output location.  An output

         * location is a location that is conventionally used for

         * output.

         *

         * @return true if this is an output location, false otherwise

         */

        boolean isOutputLocation();

        /**

         * Indicates if this location is expected to contain modules,

         * as compared to a location which contains packages and classes.

         *

         * @return true if this location is expected to contain modules

         * @since 9

         */

        default boolean isModuleLocation() {

            return false;

        }

    }

    /**

     * Returns a class loader for loading plug-ins from the given

     * location.  For example, to load annotation processors, a

     * compiler will request a class loader for the {@link

     * StandardLocation#ANNOTATION_PROCESSOR_PATH

     * ANNOTATION_PROCESSOR_PATH} location.

     *

     * @param location a location

     * @return a class loader for the given location; or {@code null}

     * if loading plug-ins from the given location is disabled or if

     * the location is not known

     * @throws SecurityException if a class loader can not be created

     * in the current security context

     * @throws IllegalStateException if {@link #close} has been called

     * and this file manager cannot be reopened

     */

    ClassLoader getClassLoader(Location location);

    /**

     * Lists all file objects matching the given criteria in the given

     * location.  List file objects in "subpackages" if recurse is

     * true.

     *

     * <p>Note: even if the given location is unknown to this file

     * manager, it may not return {@code null}.  Also, an unknown

     * location may not cause an exception.

     *

     * @param location     a location

     * @param packageName  a package name

     * @param kinds        return objects only of these kinds

     * @param recurse      if true include "subpackages"

     * @return an Iterable of file objects matching the given criteria

     * @throws IOException if an I/O error occurred, or if {@link

     * #close} has been called and this file manager cannot be

     * reopened

     * @throws IllegalStateException if {@link #close} has been called

     * and this file manager cannot be reopened

     */

    Iterable<JavaFileObject> list(Location location,

                                  String packageName,

                                  Set<Kind> kinds,

                                  boolean recurse)

        throws IOException;

    /**

     * Infers a binary name of a file object based on a location.  The

     * binary name returned might not be a valid binary name according to

     * <cite>The Java&trade; Language Specification</cite>.

     *

     * @param location a location

     * @param file a file object

     * @return a binary name or {@code null} the file object is not

     * found in the given location

     * @throws IllegalStateException if {@link #close} has been called

     * and this file manager cannot be reopened

     */

    String inferBinaryName(Location location, JavaFileObject file);

    /**

     * Compares two file objects and return true if they represent the

     * same underlying object.

     *

     * @param a a file object

     * @param b a file object

     * @return true if the given file objects represent the same

     * underlying object

     *

     * @throws IllegalArgumentException if either of the arguments

     * were created with another file manager and this file manager

     * does not support foreign file objects

     */

    boolean isSameFile(FileObject a, FileObject b);

    /**

     * Handles one option.  If {@code current} is an option to this

     * file manager it will consume any arguments to that option from

     * {@code remaining} and return true, otherwise return false.

     *

     * @param current current option

     * @param remaining remaining options

     * @return true if this option was handled by this file manager,

     * false otherwise

     * @throws IllegalArgumentException if this option to this file

     * manager is used incorrectly

     * @throws IllegalStateException if {@link #close} has been called

     * and this file manager cannot be reopened

     */

    boolean handleOption(String current, Iterator<String> remaining);

    /**

     * Determines if a location is known to this file manager.

     *

     * @param location a location

     * @return true if the location is known

     */

    boolean hasLocation(Location location);

    /**

     * Returns a {@linkplain JavaFileObject file object} for input

     * representing the specified class of the specified kind in the

     * given location.

     *

     * @param location a location

     * @param className the name of a class

     * @param kind the kind of file, must be one of {@link

     * JavaFileObject.Kind#SOURCE SOURCE} or {@link

     * JavaFileObject.Kind#CLASS CLASS}

     * @return a file object, might return {@code null} if the

     * file does not exist

     * @throws IllegalArgumentException if the location is not known

     * to this file manager and the file manager does not support

     * unknown locations, or if the kind is not valid

     * @throws IOException if an I/O error occurred, or if {@link

     * #close} has been called and this file manager cannot be

     * reopened

     * @throws IllegalStateException if {@link #close} has been called

     * and this file manager cannot be reopened

     */

    JavaFileObject getJavaFileForInput(Location location,

                                       String className,

                                       Kind kind)

        throws IOException;

    /**

     * Returns a {@linkplain JavaFileObject file object} for output

     * representing the specified class of the specified kind in the

     * given location.

     *

     * <p>Optionally, this file manager might consider the sibling as

     * a hint for where to place the output.  The exact semantics of

     * this hint is unspecified.  The JDK compiler, javac, for

     * example, will place class files in the same directories as

     * originating source files unless a class file output directory

     * is provided.  To facilitate this behavior, javac might provide

     * the originating source file as sibling when calling this

     * method.

     *

     * @param location a location

     * @param className the name of a class

     * @param kind the kind of file, must be one of {@link

     * JavaFileObject.Kind#SOURCE SOURCE} or {@link

     * JavaFileObject.Kind#CLASS CLASS}

     * @param sibling a file object to be used as hint for placement;

     * might be {@code null}

     * @return a file object for output

     * @throws IllegalArgumentException if sibling is not known to

     * this file manager, or if the location is not known to this file

     * manager and the file manager does not support unknown

     * locations, or if the kind is not valid

     * @throws IOException if an I/O error occurred, or if {@link

     * #close} has been called and this file manager cannot be

     * reopened

     * @throws IllegalStateException {@link #close} has been called

     * and this file manager cannot be reopened

     */

    JavaFileObject getJavaFileForOutput(Location location,

                                        String className,

                                        Kind kind,

                                        FileObject sibling)

        throws IOException;

    /**

     * Returns a {@linkplain FileObject file object} for input

     * representing the specified <a href="JavaFileManager.html#relative_name">relative

     * name</a> in the specified package in the given location.

     *

     * <p>If the returned object represents a {@linkplain

     * JavaFileObject.Kind#SOURCE source} or {@linkplain

     * JavaFileObject.Kind#CLASS class} file, it must be an instance

     * of {@link JavaFileObject}.

     *

     * <p>Informally, the file object returned by this method is

     * located in the concatenation of the location, package name, and

     * relative name.  For example, to locate the properties file

     * "resources/compiler.properties" in the package

     * "com.sun.tools.javac" in the {@linkplain

     * StandardLocation#SOURCE_PATH SOURCE_PATH} location, this method

     * might be called like so:

     *

     * <pre>getFileForInput(SOURCE_PATH, "com.sun.tools.javac", "resources/compiler.properties");</pre>

     *

     * <p>If the call was executed on Windows, with SOURCE_PATH set to

     * <code>"C:\Documents&nbsp;and&nbsp;Settings\UncleBob\src\share\classes"</code>,

     * a valid result would be a file object representing the file

     * <code>"C:\Documents&nbsp;and&nbsp;Settings\UncleBob\src\share\classes\com\sun\tools\javac\resources\compiler.properties"</code>.

     *

     * @param location a location

     * @param packageName a package name

     * @param relativeName a relative name

     * @return a file object, might return {@code null} if the file

     * does not exist

     * @throws IllegalArgumentException if the location is not known

     * to this file manager and the file manager does not support

     * unknown locations, or if {@code relativeName} is not valid

     * @throws IOException if an I/O error occurred, or if {@link

     * #close} has been called and this file manager cannot be

     * reopened

     * @throws IllegalStateException if {@link #close} has been called

     * and this file manager cannot be reopened

     */

    FileObject getFileForInput(Location location,

                               String packageName,

                               String relativeName)

        throws IOException;

    /**

     * Returns a {@linkplain FileObject file object} for output

     * representing the specified <a href="JavaFileManager.html#relative_name">relative

     * name</a> in the specified package in the given location.

     *

     * <p>Optionally, this file manager might consider the sibling as

     * a hint for where to place the output.  The exact semantics of

     * this hint is unspecified.  The JDK compiler, javac, for

     * example, will place class files in the same directories as

     * originating source files unless a class file output directory

     * is provided.  To facilitate this behavior, javac might provide

     * the originating source file as sibling when calling this

     * method.

     *

     * <p>If the returned object represents a {@linkplain

     * JavaFileObject.Kind#SOURCE source} or {@linkplain

     * JavaFileObject.Kind#CLASS class} file, it must be an instance

     * of {@link JavaFileObject}.

     *

     * <p>Informally, the file object returned by this method is

     * located in the concatenation of the location, package name, and

     * relative name or next to the sibling argument.  See {@link

     * #getFileForInput getFileForInput} for an example.

     *

     * @param location a location

     * @param packageName a package name

     * @param relativeName a relative name

     * @param sibling a file object to be used as hint for placement;

     * might be {@code null}

     * @return a file object

     * @throws IllegalArgumentException if sibling is not known to

     * this file manager, or if the location is not known to this file

     * manager and the file manager does not support unknown

     * locations, or if {@code relativeName} is not valid

     * @throws IOException if an I/O error occurred, or if {@link

     * #close} has been called and this file manager cannot be

     * reopened

     * @throws IllegalStateException if {@link #close} has been called

     * and this file manager cannot be reopened

     */

    FileObject getFileForOutput(Location location,

                                String packageName,

                                String relativeName,

                                FileObject sibling)

        throws IOException;

    /**

     * Flushes any resources opened for output by this file manager

     * directly or indirectly.  Flushing a closed file manager has no

     * effect.

     *

     * @throws IOException if an I/O error occurred

     * @see #close

     */

    @Override

    void flush() throws IOException;

    /**

     * Releases any resources opened by this file manager directly or

     * indirectly.  This might render this file manager useless and

     * the effect of subsequent calls to methods on this object or any

     * objects obtained through this object is undefined unless

     * explicitly allowed.  However, closing a file manager which has

     * already been closed has no effect.

     *

     * @throws IOException if an I/O error occurred

     * @see #flush

     */

    @Override

    void close() throws IOException;

    /**

     * Gets a location for a named module within a module-oriented location.

     *

     * @param location the module-oriented location

     * @param moduleName the name of the module to be found

     * @return the location for the named module

     *

     * @throws IOException if an I/O error occurred

     * @throws UnsupportedOperationException if this operation if not supported by this file manager

     * @since 9

     */ // TODO: describe failure modes

    default Location getModuleLocation(Location location, String moduleName) throws IOException {

        throw new UnsupportedOperationException();

    }

    /**

     * Gets a location for the module containing a specific file representing a Java

     * source or class.

     *

     * @param location a module-oriented location

     * @param fo the file

     * @param pkgName the package name for the class(es) defined in this file

     * @return the module containing the file

     *

     * @throws IOException if an I/O error occurred

     * @throws UnsupportedOperationException if this operation if not supported by this file manager

     * @since 9

     */ // TODO: describe failure modes

    default Location getModuleLocation(Location location, JavaFileObject fo, String pkgName) throws IOException {

        throw new UnsupportedOperationException();

    }

    /**

     * Get a service loader for a specific service class from a given location.

     *

     * @param location the location

     * @param service  the {@code Class} object of the service class

     * @param <S> the service class

     * @return a service loader for the given service class

     *

     * @throws IOException if an I/O error occurred

     * @throws UnsupportedOperationException if this operation if not supported by this file manager

     * @since 9

     */ // TODO: describe failure modes

    default <S> ServiceLoader<S> getServiceLoader(Location location, Class<S> service) throws  IOException {

        throw new UnsupportedOperationException();

    }

    /**

     * Infer the name of the module from its location, as returned by

     * getModuleLocation or listModuleLocations.

     *

     * @param location a location representing a module

     * @return the name of the module

     *

     * @throws IOException if an I/O error occurred

     * @throws UnsupportedOperationException if this operation if not supported by this file manager

     * @since 9

     */ // TODO: describe failure modes

    default String inferModuleName(Location location) throws IOException {

        throw new UnsupportedOperationException();

    }

    /**

     * Lists the modules in a module-oriented location.

     *

     * @param location  the location for which to list the modules

     * @return  a series of sets of locations containing modules

     *

     * @throws IOException if an I/O error occurred

     * @throws UnsupportedOperationException if this operation if not supported by this file manager

     * @since 9

     */ // TODO: describe failure modes

    default Iterable<Set<Location>> listModuleLocations(Location location) throws IOException {

        throw new UnsupportedOperationException();

    }

}