1 /* 2 * Copyright (c) 2014, 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 package jdk.internal.jrtfs; 26 27 import java.io.IOException; 28 import java.net.URISyntaxException; 29 import java.net.URL; 30 import java.nio.file.Files; 31 import java.nio.file.FileSystem; 32 import java.nio.file.FileSystems; 33 import java.nio.file.FileSystemNotFoundException; 34 import java.nio.file.Path; 35 import java.nio.file.Paths; 36 import java.security.AccessController; 37 import java.security.CodeSource; 38 import java.security.PrivilegedAction; 39 40 import jdk.internal.jimage.ImageReader; 41 import jdk.internal.jimage.ImageReader.Node; 42 43 /** 44 * @implNote This class needs to maintain JDK 8 source compatibility. 45 * 46 * It is used internally in the JDK to implement jimage/jrtfs access, 47 * but also compiled and delivered as part of the jrtfs.jar to support access 48 * to the jimage file provided by the shipped JDK by tools running on JDK 8. 49 */ 50 abstract class SystemImage { 51 findNode(String path)52 abstract Node findNode(String path) throws IOException; getResource(Node node)53 abstract byte[] getResource(Node node) throws IOException; close()54 abstract void close() throws IOException; 55 open()56 static SystemImage open() throws IOException { 57 if (modulesImageExists) { 58 // open a .jimage and build directory structure 59 final ImageReader image = ImageReader.open(moduleImageFile); 60 image.getRootDirectory(); 61 return new SystemImage() { 62 @Override 63 Node findNode(String path) throws IOException { 64 return image.findNode(path); 65 } 66 @Override 67 byte[] getResource(Node node) throws IOException { 68 return image.getResource(node); 69 } 70 @Override 71 void close() throws IOException { 72 image.close(); 73 } 74 }; 75 } 76 if (Files.notExists(explodedModulesDir)) 77 throw new FileSystemNotFoundException(explodedModulesDir.toString()); 78 return new ExplodedImage(explodedModulesDir); 79 } 80 81 static final String RUNTIME_HOME; 82 // "modules" jimage file Path 83 final static Path moduleImageFile; 84 // "modules" jimage exists or not? 85 final static boolean modulesImageExists; 86 // <JAVA_HOME>/modules directory Path 87 static final Path explodedModulesDir; 88 89 static { 90 PrivilegedAction<String> pa = SystemImage::findHome; 91 RUNTIME_HOME = AccessController.doPrivileged(pa); 92 93 FileSystem fs = FileSystems.getDefault(); 94 moduleImageFile = fs.getPath(RUNTIME_HOME, "lib", "modules"); 95 explodedModulesDir = fs.getPath(RUNTIME_HOME, "modules"); 96 97 modulesImageExists = AccessController.doPrivileged( 98 new PrivilegedAction<Boolean>() { 99 @Override 100 public Boolean run() { 101 return Files.isRegularFile(moduleImageFile); 102 } 103 }); 104 } 105 106 /** 107 * Returns the appropriate JDK home for this usage of the FileSystemProvider. 108 * When the CodeSource is null (null loader) then jrt:/ is the current runtime, 109 * otherwise the JDK home is located relative to jrt-fs.jar. 110 */ 111 private static String findHome() { 112 CodeSource cs = SystemImage.class.getProtectionDomain().getCodeSource(); 113 if (cs == null) 114 return System.getProperty("java.home"); 115 116 // assume loaded from $TARGETJDK/lib/jrt-fs.jar 117 URL url = cs.getLocation(); 118 if (!url.getProtocol().equalsIgnoreCase("file")) 119 throw new InternalError(url + " loaded in unexpected way"); 120 try { 121 Path lib = Paths.get(url.toURI()).getParent(); 122 if (!lib.getFileName().toString().equals("lib")) 123 throw new InternalError(url + " unexpected path"); 124 125 return lib.getParent().toString(); 126 } catch (URISyntaxException e) { 127 throw new InternalError(e); 128 } 129 } 130 } 131