1 /* 2 * Copyright (c) 2017, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 import java.io.InputStream; 25 import java.io.IOException; 26 import java.lang.module.ModuleReader; 27 import java.lang.module.ModuleReference; 28 import java.net.URI; 29 import java.nio.file.Files; 30 import java.nio.file.Path; 31 import java.nio.file.Paths; 32 import jdk.internal.module.ClassFileConstants; 33 import jdk.internal.module.ClassFileAttributes; 34 import jdk.internal.module.ClassFileAttributes.ModuleTargetAttribute; 35 import jdk.internal.org.objectweb.asm.Attribute; 36 import jdk.internal.org.objectweb.asm.ClassReader; 37 import jdk.internal.org.objectweb.asm.ClassVisitor; 38 import jdk.internal.org.objectweb.asm.Opcodes; 39 40 public class ModuleTargetHelper { 41 private ModuleTargetHelper() {} 42 43 public static final class ModuleTarget { 44 private String osName, osArch; 45 46 public ModuleTarget(String osName, String osArch) { 47 this.osName = osName; 48 this.osArch = osArch; 49 } 50 51 public String osName() { 52 return osName; 53 } 54 55 public String osArch() { 56 return osArch; 57 } 58 } 59 60 public static ModuleTarget getJavaBaseTarget() throws IOException { 61 Path p = Paths.get(URI.create("jrt:/modules/java.base/module-info.class")); 62 try (InputStream in = Files.newInputStream(p)) { 63 return read(in); 64 } 65 } 66 67 public static ModuleTarget read(InputStream in) throws IOException { 68 ModuleTargetAttribute[] modTargets = new ModuleTargetAttribute[1]; 69 ClassVisitor cv = new ClassVisitor(Opcodes.ASM5) { 70 @Override 71 public void visitAttribute(Attribute attr) { 72 if (attr instanceof ModuleTargetAttribute) { 73 modTargets[0] = (ModuleTargetAttribute)attr; 74 } 75 } 76 }; 77 78 // prototype of attributes that should be parsed 79 Attribute[] attrs = new Attribute[] { 80 new ModuleTargetAttribute() 81 }; 82 83 // parse module-info.class 84 ClassReader cr = new ClassReader(in); 85 cr.accept(cv, attrs, 0); 86 if (modTargets[0] != null) { 87 return new ModuleTarget(modTargets[0].osName(), modTargets[0].osArch()); 88 } 89 90 return null; 91 } 92 93 public static ModuleTarget read(ModuleReference modRef) throws IOException { 94 ModuleReader reader = modRef.open(); 95 try (InputStream in = reader.open("module-info.class").get()) { 96 return read(in); 97 } finally { 98 reader.close(); 99 } 100 } 101 }