Java tutorial
/* * 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.*; import java.net.URI; import java.nio.CharBuffer; import java.util.Objects; import javax.lang.model.element.Modifier; import javax.lang.model.element.NestingKind; import javax.tools.JavaFileObject.Kind; /** * Provides simple implementations for most methods in JavaFileObject. * This class is designed to be subclassed and used as a basis for * JavaFileObject implementations. Subclasses can override the * implementation and specification of any method of this class as * long as the general contract of JavaFileObject is obeyed. * * @author Peter von der Ahé * @since 1.6 */ public class SimpleJavaFileObject implements JavaFileObject { /** * A URI for this file object. */ protected final URI uri; /** * The kind of this file object. */ protected final Kind kind; /** * Construct a SimpleJavaFileObject of the given kind and with the * given URI. * * @param uri the URI for this file object * @param kind the kind of this file object */ protected SimpleJavaFileObject(URI uri, Kind kind) { Objects.requireNonNull(uri); Objects.requireNonNull(kind); if (uri.getPath() == null) throw new IllegalArgumentException("URI must have a path: " + uri); this.uri = uri; this.kind = kind; } public URI toUri() { return uri; } public String getName() { return toUri().getPath(); } /** * This implementation always throws {@linkplain * UnsupportedOperationException}. Subclasses can change this * behavior as long as the contract of {@link FileObject} is * obeyed. */ public InputStream openInputStream() throws IOException { throw new UnsupportedOperationException(); } /** * This implementation always throws {@linkplain * UnsupportedOperationException}. Subclasses can change this * behavior as long as the contract of {@link FileObject} is * obeyed. */ public OutputStream openOutputStream() throws IOException { throw new UnsupportedOperationException(); } /** * Wraps the result of {@linkplain #getCharContent} in a Reader. * Subclasses can change this behavior as long as the contract of * {@link FileObject} is obeyed. * * @param ignoreEncodingErrors {@inheritDoc} * @return a Reader wrapping the result of getCharContent * @throws IllegalStateException {@inheritDoc} * @throws UnsupportedOperationException {@inheritDoc} * @throws IOException {@inheritDoc} */ public Reader openReader(boolean ignoreEncodingErrors) throws IOException { CharSequence charContent = getCharContent(ignoreEncodingErrors); if (charContent == null) throw new UnsupportedOperationException(); if (charContent instanceof CharBuffer) { CharBuffer buffer = (CharBuffer) charContent; if (buffer.hasArray()) return new CharArrayReader(buffer.array()); } return new StringReader(charContent.toString()); } /** * This implementation always throws {@linkplain * UnsupportedOperationException}. Subclasses can change this * behavior as long as the contract of {@link FileObject} is * obeyed. */ public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException { throw new UnsupportedOperationException(); } /** * Wraps the result of openOutputStream in a Writer. Subclasses * can change this behavior as long as the contract of {@link * FileObject} is obeyed. * * @return a Writer wrapping the result of openOutputStream * @throws IllegalStateException {@inheritDoc} * @throws UnsupportedOperationException {@inheritDoc} * @throws IOException {@inheritDoc} */ public Writer openWriter() throws IOException { return new OutputStreamWriter(openOutputStream()); } /** * This implementation returns {@code 0L}. Subclasses can change * this behavior as long as the contract of {@link FileObject} is * obeyed. * * @return {@code 0L} */ public long getLastModified() { return 0L; } /** * This implementation does nothing. Subclasses can change this * behavior as long as the contract of {@link FileObject} is * obeyed. * * @return {@code false} */ public boolean delete() { return false; } /** * @return {@code this.kind} */ public Kind getKind() { return kind; } /** * This implementation compares the path of its URI to the given * simple name. This method returns true if the given kind is * equal to the kind of this object, and if the path is equal to * {@code simpleName + kind.extension} or if it ends with {@code * "/" + simpleName + kind.extension}. * * <p>This method calls {@link #getKind} and {@link #toUri} and * does not access the fields {@link #uri} and {@link #kind} * directly. * * <p>Subclasses can change this behavior as long as the contract * of {@link JavaFileObject} is obeyed. */ public boolean isNameCompatible(String simpleName, Kind kind) { String baseName = simpleName + kind.extension; return kind.equals(getKind()) && (baseName.equals(toUri().getPath()) || toUri().getPath().endsWith("/" + baseName)); } /** * This implementation returns {@code null}. Subclasses can * change this behavior as long as the contract of * {@link JavaFileObject} is obeyed. */ public NestingKind getNestingKind() { return null; } /** * This implementation returns {@code null}. Subclasses can * change this behavior as long as the contract of * {@link JavaFileObject} is obeyed. */ public Modifier getAccessLevel() { return null; } @Override public String toString() { return getClass().getName() + "[" + toUri() + "]"; } }