1 /* 2 * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package jdk.internal.jimage; 27 28 import java.io.IOException; 29 import java.io.UncheckedIOException; 30 import java.nio.file.Path; 31 import java.nio.file.Paths; 32 import java.util.concurrent.ConcurrentHashMap; 33 import java.util.Map; 34 import java.util.Objects; 35 import java.util.function.Function; 36 37 /** 38 * Factory to get ImageReader 39 * 40 * @implNote This class needs to maintain JDK 8 source compatibility. 41 * 42 * It is used internally in the JDK to implement jimage/jrtfs access, 43 * but also compiled and delivered as part of the jrtfs.jar to support access 44 * to the jimage file provided by the shipped JDK by tools running on JDK 8. 45 */ 46 public class ImageReaderFactory { 47 private ImageReaderFactory() {} 48 49 private static final String JAVA_HOME = System.getProperty("java.home"); 50 private static final Path BOOT_MODULES_JIMAGE = 51 Paths.get(JAVA_HOME, "lib", "modules"); 52 53 private static final Map<Path, ImageReader> readers = new ConcurrentHashMap<>(); 54 55 /** 56 * Returns an {@code ImageReader} to read from the given image file 57 */ 58 public static ImageReader get(Path jimage) throws IOException { 59 Objects.requireNonNull(jimage); 60 try { 61 return readers.computeIfAbsent(jimage, OPENER); 62 } catch (UncheckedIOException io) { 63 throw io.getCause(); 64 } 65 } 66 67 private static Function<Path, ImageReader> OPENER = new Function<Path, ImageReader>() { 68 public ImageReader apply(Path path) { 69 try { 70 return ImageReader.open(path); 71 } catch (IOException io) { 72 throw new UncheckedIOException(io); 73 } 74 } 75 }; 76 77 /** 78 * Returns the {@code ImageReader} to read the image file in this 79 * run-time image. 80 * 81 * @throws UncheckedIOException if an I/O error occurs 82 */ 83 public static ImageReader getImageReader() { 84 try { 85 return get(BOOT_MODULES_JIMAGE); 86 } catch (IOException ioe) { 87 throw new UncheckedIOException(ioe); 88 } 89 } 90 }