--- /dev/null 2015-06-23 14:29:17.000000000 +0200 +++ new/src/java.base/share/classes/jdk/internal/jimage/ImageReaderFactory.java 2015-06-23 14:29:16.000000000 +0200 @@ -0,0 +1,79 @@ +/* + * Copyright (c) 2015, 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 jdk.internal.jimage; + +import java.io.IOException; +import java.io.UncheckedIOException; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.concurrent.ConcurrentHashMap; +import java.util.Map; + +/** + * Factory to get ImageReader + */ +public class ImageReaderFactory { + private ImageReaderFactory() {} + + private static final String JAVA_HOME = System.getProperty("java.home"); + private static final Path BOOT_MODULES_JIMAGE = + Paths.get(JAVA_HOME, "lib", "modules", "bootmodules.jimage"); + + private static final Map readers = new ConcurrentHashMap<>(); + + /** + * Returns an {@code ImageReader} to read from the given image file + */ + public static ImageReader get(Path jimage) throws IOException { + ImageReader reader = readers.get(jimage); + if (reader != null) { + return reader; + } + reader = ImageReader.open(jimage.toString()); + // potential race with other threads opening the same URL + ImageReader r = readers.putIfAbsent(jimage, reader); + if (r == null) { + return reader; + } else { + reader.close(); + return r; + } + } + + /** + * Returns the {@code ImageReader} to read the image file in this + * run-time image. + * + * @throws UncheckedIOException if an I/O error occurs + */ + public static ImageReader getImageReader() { + try { + return get(BOOT_MODULES_JIMAGE); + } catch (IOException ioe) { + throw new UncheckedIOException(ioe); + } + } +}