1 /* 2 * Copyright (c) 2010, 2018, 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 25 import java.io.File; 26 import java.io.ByteArrayInputStream; 27 import java.io.FileInputStream; 28 29 public class LE2_Loader extends ClassLoader { 30 31 private static String classPath; 32 static { 33 classPath = System.getProperty("test.classes"); 34 if (classPath == null) { 35 classPath = ""; 36 } else { 37 classPath = classPath + File.separator; 38 } 39 } 40 41 // Print routine to generate indented output that 42 // reflects recursive actions of the classloader. 43 int _recur = 0; 44 public void print(String msg) { 45 for (int i = 0; i < _recur; i++) { 46 System.out.print(" "); 47 } 48 System.out.println(">>LE2_Loader>> " + msg); 49 } 50 51 protected Class findClass2(String name) throws ClassNotFoundException { 52 print("Fetching the implementation of " + name); 53 int old = _recur; 54 String filename = classPath + name.replace(".", "/") + ".impl2"; 55 try { 56 57 FileInputStream fi = new FileInputStream(filename); 58 byte result[] = new byte[fi.available()]; 59 fi.read(result); 60 61 print("call defineClass() on " + name); 62 _recur++; 63 // This will throw the expected LinkageError when loading the 64 // second version of class B. 65 Class clazz = defineClass(name, result, 0, result.length); 66 _recur = old; 67 print("Returning newly loaded class."); 68 return clazz; 69 } catch (Exception e) { 70 _recur = old; 71 print("Not found on disk: " + filename); 72 // If we caught an exception, either the class was not found or 73 // it was unreadable by our process. 74 return null; 75 } 76 } 77 78 protected synchronized Class loadClass(String name, boolean resolve) throws ClassNotFoundException { 79 // Attempt a disk load first. 80 Class c = findClass2(name); 81 if (c == null) { 82 // Check if the class has already been loaded. 83 print("Checking for prior loaded class " + name); 84 c = findLoadedClass(name); 85 print("Letting super-loader load " + name); 86 int old = _recur; 87 _recur++; 88 c = super.loadClass(name, false); 89 _recur = old; 90 } 91 if (resolve) { print("Resolving class " + name); resolveClass(c); } 92 print("Returning class " + c.getClassLoader() + ":" + name); 93 return c; 94 } 95 }