Java example source code file (JavaFileManager.java)

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Java - Java tags/keywords

classloader, closeable, fileobject, flushable, ioexception, iterable, iterator, javafilemanager, javafileobject, kind, location, optionchecker, set, string, util

The JavaFileManager.java Java example source code

/*
 * Copyright (c) 2005, 2006, 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 javax.tools;

import java.io.Closeable;
import java.io.Flushable;
import java.io.IOException;
import java.util.Iterator;
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 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™ Virtual Machine Specification.

 * <blockquote>

 *   <i>Discussion: 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™ Language Specification,
 *   section 13.1 "The Form of a Binary".
 * </p>
 *
 * <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>Relative names: 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 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)

* * <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>Implementation note: 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 { /** * Gets 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(); } /** * Gets 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™ Language Specification. * * @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); /** * Gets 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; /** * Gets 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; /** * Gets 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"); * * <p>If the call was executed on Windows, with SOURCE_PATH set to * <code>"C:\Documents and Settings\UncleBob\src\share\classes", * a valid result would be a file object representing the file * <code>"C:\Documents and Settings\UncleBob\src\share\classes\com\sun\tools\javac\resources\compiler.properties". * * @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; /** * Gets 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 */ 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 */ void close() throws IOException; }