001    /*
002     * Copyright 2004 Sun Microsystems, Inc.  All Rights Reserved.
003     * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004     *
005     * This code is free software; you can redistribute it and/or modify it
006     * under the terms of the GNU General Public License version 2 only, as
007     * published by the Free Software Foundation.  Sun designates this
008     * particular file as subject to the "Classpath" exception as provided
009     * by Sun in the LICENSE file that accompanied this code.
010     *
011     * This code is distributed in the hope that it will be useful, but WITHOUT
012     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013     * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
014     * version 2 for more details (a copy is included in the LICENSE file that
015     * accompanied this code).
016     *
017     * You should have received a copy of the GNU General Public License version
018     * 2 along with this work; if not, write to the Free Software Foundation,
019     * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020     *
021     * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022     * CA 95054 USA or visit www.sun.com if you need additional information or
023     * have any questions.
024     */
025    
026    package com.sun.mirror.apt;
027    
028    
029    import java.io.*;
030    
031    
032    /**
033     * This interface supports the creation of new files by an
034     * annotation processor.
035     * Files created in this way will be known to the annotation processing
036     * tool implementing this interface, better enabling the tool to manage them.
037     * Four kinds of files are distinguished:
038     * source files, class files, other text files, and other binary files.
039     * The latter two are collectively referred to as <i>auxiliary</i> files.
040     *
041     * <p> There are two distinguished locations (subtrees within the
042     * file system) where newly created files are placed:
043     * one for new source files, and one for new class files.
044     * (These might be specified on a tool's command line, for example,
045     * using flags such as <tt>-s</tt> and <tt>-d</tt>.)
046     * Auxiliary files may be created in either location.
047     *
048     * <p> During each run of an annotation processing tool, a file
049     * with a given pathname may be created only once.  If that file already
050     * exists before the first attempt to create it, the old contents will
051     * be deleted.  Any subsequent attempt to create the same file during
052     * a run will fail.
053     *
054     * @author Joseph D. Darcy
055     * @author Scott Seligman
056     * @since 1.5
057     */
058    
059    public interface Filer {
060    
061        /**
062         * Creates a new source file and returns a writer for it.
063         * The file's name and path (relative to the root of all newly created
064         * source files) is based on the type to be declared in that file.
065         * If more than one type is being declared, the name of the principal
066         * top-level type (the public one, for example) should be used.
067         *
068         * <p> The {@linkplain java.nio.charset.Charset charset} used to
069         * encode the file is determined by the implementation.
070         * An annotation processing tool may have an <tt>-encoding</tt>
071         * flag or the like for specifying this.  It will typically use
072         * the platform's default encoding if none is specified.
073         *
074         * @param name  canonical (fully qualified) name of the principal type
075         *          being declared in this file
076         * @return a writer for the new file
077         * @throws IOException if the file cannot be created
078         */
079        PrintWriter createSourceFile(String name) throws IOException;
080    
081        /**
082         * Creates a new class file, and returns a stream for writing to it.
083         * The file's name and path (relative to the root of all newly created
084         * class files) is based on the name of the type being written.
085         *
086         * @param name canonical (fully qualified) name of the type being written
087         * @return a stream for writing to the new file
088         * @throws IOException if the file cannot be created
089         */
090        OutputStream createClassFile(String name) throws IOException;
091    
092        /**
093         * Creates a new text file, and returns a writer for it.
094         * The file is located along with either the
095         * newly created source or newly created binary files.  It may be
096         * named relative to some package (as are source and binary files),
097         * and from there by an arbitrary pathname.  In a loose sense, the
098         * pathname of the new file will be the concatenation of
099         * <tt>loc</tt>, <tt>pkg</tt>, and <tt>relPath</tt>.
100         *
101         * <p> A {@linkplain java.nio.charset.Charset charset} for
102         * encoding the file may be provided.  If none is given, the
103         * charset used to encode source files
104         * (see {@link #createSourceFile(String)}) will be used.
105         *
106         * @param loc location of the new file
107         * @param pkg package relative to which the file should be named,
108         *          or the empty string if none
109         * @param relPath final pathname components of the file
110         * @param charsetName the name of the charset to use, or null if none
111         *          is being explicitly specified
112         * @return a writer for the new file
113         * @throws IOException if the file cannot be created
114         */
115        PrintWriter createTextFile(Location loc,
116                                   String pkg,
117                                   File relPath,
118                                   String charsetName) throws IOException;
119    
120        /**
121         * Creates a new binary file, and returns a stream for writing to it.
122         * The file is located along with either the
123         * newly created source or newly created binary files.  It may be
124         * named relative to some package (as are source and binary files),
125         * and from there by an arbitrary pathname.  In a loose sense, the
126         * pathname of the new file will be the concatenation of
127         * <tt>loc</tt>, <tt>pkg</tt>, and <tt>relPath</tt>.
128         *
129         * @param loc location of the new file
130         * @param pkg package relative to which the file should be named,
131         *          or the empty string if none
132         * @param relPath final pathname components of the file
133         * @return a stream for writing to the new file
134         * @throws IOException if the file cannot be created
135         */
136        OutputStream createBinaryFile(Location loc,
137                                      String pkg,
138                                      File relPath) throws IOException;
139    
140    
141        /**
142         * Locations (subtrees within the file system) where new files are created.
143         */
144        enum Location {
145            /** The location of new source files. */
146            SOURCE_TREE,
147            /** The location of new class files. */
148            CLASS_TREE
149        }
150    }