| /* |
| * 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.annotation.processing; |
| |
| import javax.tools.JavaFileManager; |
| import javax.tools.*; |
| import javax.lang.model.element.Element; |
| import java.io.IOException; |
| |
| /** |
| * This interface supports the creation of new files by an annotation |
| * processor. Files created in this way will be known to the |
| * annotation processing tool implementing this interface, better |
| * enabling the tool to manage them. Source and class files so |
| * created will be {@linkplain RoundEnvironment#getRootElements |
| * considered for processing} by the tool in a subsequent {@linkplain |
| * RoundEnvironment round of processing} after the {@code close} |
| * method has been called on the {@code Writer} or {@code |
| * OutputStream} used to write the contents of the file. |
| * |
| * Three kinds of files are distinguished: source files, class files, |
| * and auxiliary resource files. |
| * |
| * <p> There are two distinguished supported locations (subtrees |
| * within the logical file system) where newly created files are |
| * placed: one for {@linkplain |
| * javax.tools.StandardLocation#SOURCE_OUTPUT new source files}, and |
| * one for {@linkplain javax.tools.StandardLocation#CLASS_OUTPUT new |
| * class files}. (These might be specified on a tool's command line, |
| * for example, using flags such as {@code -s} and {@code -d}.) The |
| * actual locations for new source files and new class files may or |
| * may not be distinct on a particular run of the tool. Resource |
| * files may be created in either location. The methods for reading |
| * and writing resources take a relative name argument. A relative |
| * name is a non-null, non-empty sequence of path segments separated |
| * by {@code '/'}; {@code '.'} and {@code '..'} 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. |
| * |
| * <p>The file creation methods take a variable number of arguments to |
| * allow the <em>originating elements</em> to be provided as hints to |
| * the tool infrastructure to better manage dependencies. The |
| * originating elements are the types or packages (representing {@code |
| * package-info} files) which caused an annotation processor to |
| * attempt to create a new file. For example, if an annotation |
| * processor tries to create a source file, {@code |
| * GeneratedFromUserSource}, in response to processing |
| * |
| * <blockquote><pre> |
| * @Generate |
| * public class UserSource {} |
| * </pre></blockquote> |
| * |
| * the type element for {@code UserSource} should be passed as part of |
| * the creation method call as in: |
| * |
| * <blockquote><pre> |
| * filer.createSourceFile("GeneratedFromUserSource", |
| * eltUtils.getTypeElement("UserSource")); |
| * </pre></blockquote> |
| * |
| * If there are no originating elements, none need to be passed. This |
| * information may be used in an incremental environment to determine |
| * the need to rerun processors or remove generated files. |
| * Non-incremental environments may ignore the originating element |
| * information. |
| * |
| * <p> During each run of an annotation processing tool, a file with a |
| * given pathname may be created only once. If that file already |
| * exists before the first attempt to create it, the old contents will |
| * be deleted. Any subsequent attempt to create the same file during |
| * a run will throw a {@link FilerException}, as will attempting to |
| * create both a class file and source file for the same type name or |
| * same package name. The {@linkplain Processor initial inputs} to |
| * the tool are considered to be created by the zeroth round; |
| * therefore, attempting to create a source or class file |
| * corresponding to one of those inputs will result in a {@link |
| * FilerException}. |
| * |
| * <p> In general, processors must not knowingly attempt to overwrite |
| * existing files that were not generated by some processor. A {@code |
| * Filer} may reject attempts to open a file corresponding to an |
| * existing type, like {@code java.lang.Object}. Likewise, the |
| * invoker of the annotation processing tool must not knowingly |
| * configure the tool such that the discovered processors will attempt |
| * to overwrite existing files that were not generated. |
| * |
| * <p> Processors can indicate a source or class file is generated by |
| * including an {@link javax.annotation.Generated @Generated} |
| * annotation. |
| * |
| * <p> Note that some of the effect of overwriting a file can be |
| * achieved by using a <i>decorator</i>-style pattern. Instead of |
| * modifying a class directly, the class is designed so that either |
| * its superclass is generated by annotation processing or subclasses |
| * of the class are generated by annotation processing. If the |
| * subclasses are generated, the parent class may be designed to use |
| * factories instead of public constructors so that only subclass |
| * instances would be presented to clients of the parent class. |
| * |
| * @author Joseph D. Darcy |
| * @author Scott Seligman |
| * @author Peter von der Ahé |
| * @since 1.6 |
| */ |
| public interface Filer { |
| /** |
| * Creates a new source file and returns an object to allow |
| * writing to it. The file's name and path (relative to the |
| * {@linkplain StandardLocation#SOURCE_OUTPUT root output location |
| * for source files}) are based on the type to be declared in that |
| * file. If more than one type is being declared, the name of the |
| * principal top-level type (the public one, for example) should |
| * be used. A source file can also be created to hold information |
| * about a package, including package annotations. To create a |
| * source file for a named package, have {@code name} be the |
| * package's name followed by {@code ".package-info"}; to create a |
| * source file for an unnamed package, use {@code "package-info"}. |
| * |
| * <p> Note that to use a particular {@linkplain |
| * java.nio.charset.Charset charset} to encode the contents of the |
| * file, an {@code OutputStreamWriter} with the chosen charset can |
| * be created from the {@code OutputStream} from the returned |
| * object. If the {@code Writer} from the returned object is |
| * directly used for writing, its charset is determined by the |
| * implementation. An annotation processing tool may have an |
| * {@code -encoding} flag or analogous option for specifying this; |
| * otherwise, it will typically be the platform's default |
| * encoding. |
| * |
| * <p>To avoid subsequent errors, the contents of the source file |
| * should be compatible with the {@linkplain |
| * ProcessingEnvironment#getSourceVersion source version} being used |
| * for this run. |
| * |
| * @param name canonical (fully qualified) name of the principal type |
| * being declared in this file or a package name followed by |
| * {@code ".package-info"} for a package information file |
| * @param originatingElements type or package elements causally |
| * associated with the creation of this file, may be elided or |
| * {@code null} |
| * @return a {@code JavaFileObject} to write the new source file |
| * @throws FilerException if the same pathname has already been |
| * created, the same type has already been created, or the name is |
| * not valid for a type |
| * @throws IOException if the file cannot be created |
| */ |
| JavaFileObject createSourceFile(CharSequence name, |
| Element... originatingElements) throws IOException; |
| |
| /** |
| * Creates a new class file, and returns an object to allow |
| * writing to it. The file's name and path (relative to the |
| * {@linkplain StandardLocation#CLASS_OUTPUT root output location |
| * for class files}) are based on the name of the type being |
| * written. A class file can also be created to hold information |
| * about a package, including package annotations. To create a |
| * class file for a named package, have {@code name} be the |
| * package's name followed by {@code ".package-info"}; creating a |
| * class file for an unnamed package is not supported. |
| * |
| * <p>To avoid subsequent errors, the contents of the class file |
| * should be compatible with the {@linkplain |
| * ProcessingEnvironment#getSourceVersion source version} being used |
| * for this run. |
| * |
| * @param name binary name of the type being written or a package name followed by |
| * {@code ".package-info"} for a package information file |
| * @param originatingElements type or package elements causally |
| * associated with the creation of this file, may be elided or |
| * {@code null} |
| * @return a {@code JavaFileObject} to write the new class file |
| * @throws FilerException if the same pathname has already been |
| * created, the same type has already been created, or the name is |
| * not valid for a type |
| * @throws IOException if the file cannot be created |
| */ |
| JavaFileObject createClassFile(CharSequence name, |
| Element... originatingElements) throws IOException; |
| |
| /** |
| * Creates a new auxiliary resource file for writing and returns a |
| * file object for it. The file may be located along with the |
| * newly created source files, newly created binary files, or |
| * other supported location. The locations {@link |
| * StandardLocation#CLASS_OUTPUT CLASS_OUTPUT} and {@link |
| * StandardLocation#SOURCE_OUTPUT SOURCE_OUTPUT} must be |
| * supported. The resource may be named relative to some package |
| * (as are source and class files), and from there by a relative |
| * pathname. In a loose sense, the full pathname of the new file |
| * will be the concatenation of {@code location}, {@code pkg}, and |
| * {@code relativeName}. |
| * |
| * <p>Files created via this method are not registered for |
| * annotation processing, even if the full pathname of the file |
| * would correspond to the full pathname of a new source file |
| * or new class file. |
| * |
| * @param location location of the new file |
| * @param pkg package relative to which the file should be named, |
| * or the empty string if none |
| * @param relativeName final pathname components of the file |
| * @param originatingElements type or package elements causally |
| * associated with the creation of this file, may be elided or |
| * {@code null} |
| * @return a {@code FileObject} to write the new resource |
| * @throws IOException if the file cannot be created |
| * @throws FilerException if the same pathname has already been |
| * created |
| * @throws IllegalArgumentException for an unsupported location |
| * @throws IllegalArgumentException if {@code relativeName} is not relative |
| */ |
| FileObject createResource(JavaFileManager.Location location, |
| CharSequence pkg, |
| CharSequence relativeName, |
| Element... originatingElements) throws IOException; |
| |
| /** |
| * Returns an object for reading an existing resource. The |
| * locations {@link StandardLocation#CLASS_OUTPUT CLASS_OUTPUT} |
| * and {@link StandardLocation#SOURCE_OUTPUT SOURCE_OUTPUT} must |
| * be supported. |
| * |
| * @param location location of the file |
| * @param pkg package relative to which the file should be searched, |
| * or the empty string if none |
| * @param relativeName final pathname components of the file |
| * @return an object to read the file |
| * @throws FilerException if the same pathname has already been |
| * opened for writing |
| * @throws IOException if the file cannot be opened |
| * @throws IllegalArgumentException for an unsupported location |
| * @throws IllegalArgumentException if {@code relativeName} is not relative |
| */ |
| FileObject getResource(JavaFileManager.Location location, |
| CharSequence pkg, |
| CharSequence relativeName) throws IOException; |
| } |
