1 /* 2 * Copyright (c) 2013, 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.BufferedInputStream; 25 import java.io.IOException; 26 import java.io.InputStream; 27 import java.util.Map; 28 import java.util.Set; 29 import java.util.Vector; 30 import jdk.internal.org.objectweb.asm.*; 31 // Compile with -XDignore.symbol.file=true 32 33 public class BogoLoader extends ClassLoader { 34 35 static interface VisitorMaker { make(ClassVisitor visitor)36 ClassVisitor make(ClassVisitor visitor); 37 } 38 39 40 /** 41 * Use this property to verify that the desired classloading is happening. 42 */ 43 private final boolean verbose = Boolean.getBoolean("bogoloader.verbose"); 44 /** 45 * Use this property to disable replacement for testing purposes. 46 */ 47 private final boolean noReplace = Boolean.getBoolean("bogoloader.noreplace"); 48 49 /** 50 * Set of class names that should be loaded with this loader. 51 * Others are loaded with the system class loader, except for those 52 * that are transformed. 53 */ 54 private Set<String> nonSystem; 55 56 /** 57 * Map from class names to a bytecode transformer factory. 58 */ 59 private Map<String, VisitorMaker> replaced; 60 61 /** 62 * Keep track (not terribly efficiently) of which classes have already 63 * been loaded by this class loader. 64 */ 65 private final Vector<String> history = new Vector<String>(); 66 useSystemLoader(String name)67 private boolean useSystemLoader(String name) { 68 return ! nonSystem.contains(name) && ! replaced.containsKey(name); 69 } 70 BogoLoader(Set<String> non_system, Map<String, VisitorMaker> replaced)71 public BogoLoader(Set<String> non_system, Map<String, VisitorMaker> replaced) { 72 super(Thread.currentThread().getContextClassLoader()); 73 this.nonSystem = non_system; 74 this.replaced = replaced; 75 } 76 readResource(String className)77 private byte[] readResource(String className) throws IOException { 78 return readResource(className, "class"); 79 } 80 readResource(String className, String suffix)81 private byte[] readResource(String className, String suffix) throws IOException { 82 // Note to the unwary -- "/" works on Windows, leave it alone. 83 String fileName = className.replace('.', '/') + "." + suffix; 84 InputStream origStream = getResourceAsStream(fileName); 85 if (origStream == null) { 86 throw new IOException("Resource not found : " + fileName); 87 } 88 BufferedInputStream stream = new java.io.BufferedInputStream(origStream); 89 byte[] data = new byte[stream.available()]; 90 int how_many = stream.read(data); 91 // Really ought to deal with the corner cases of stream.available() 92 return data; 93 } 94 getClass(String name)95 protected byte[] getClass(String name) throws ClassNotFoundException, 96 IOException { 97 return readResource(name, "class"); 98 } 99 100 /** 101 * Loads the named class from the system class loader unless 102 * the name appears in either replaced or nonSystem. 103 * nonSystem classes are loaded into this classloader, 104 * and replaced classes get their content from the specified array 105 * of bytes (and are also loaded into this classloader). 106 */ loadClass(String name, boolean resolve)107 protected Class<?> loadClass(String name, boolean resolve) 108 throws ClassNotFoundException { 109 Class<?> clazz; 110 111 if (history.contains(name)) { 112 Class<?> c = this.findLoadedClass(name); 113 return c; 114 } 115 if (useSystemLoader(name)) { 116 clazz = findSystemClass(name); 117 if (verbose) System.err.println("Loading system class " + name); 118 } else { 119 history.add(name); 120 try { 121 if (verbose) { 122 System.err.println("Loading classloader class " + name); 123 } 124 byte[] classData = getClass(name);; 125 boolean expanded = false; 126 if (!noReplace && replaced.containsKey(name)) { 127 if (verbose) { 128 System.err.println("Replacing class " + name); 129 } 130 ClassReader cr = new ClassReader(classData); 131 ClassWriter cw = new ClassWriter(0); 132 VisitorMaker vm = replaced.get(name); 133 cr.accept(vm.make(cw), 0); 134 classData = cw.toByteArray(); 135 } 136 clazz = defineClass(name, classData, 0, classData.length); 137 } catch (java.io.EOFException ioe) { 138 throw new ClassNotFoundException( 139 "IO Exception in reading class : " + name + " ", ioe); 140 } catch (ClassFormatError ioe) { 141 throw new ClassNotFoundException( 142 "ClassFormatError in reading class file: ", ioe); 143 } catch (IOException ioe) { 144 throw new ClassNotFoundException( 145 "IO Exception in reading class file: ", ioe); 146 } 147 } 148 if (clazz == null) { 149 throw new ClassNotFoundException(name); 150 } 151 if (resolve) { 152 resolveClass(clazz); 153 } 154 return clazz; 155 } 156 } 157