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.ByteArrayInputStream; 26 import java.io.FileInputStream; 27 public class Loader2 extends ClassLoader { 28 int _recur; 29 public void print( String msg ) { 30 for( int i=0; i<_recur; i++ ) 31 System.out.print(" "); 32 System.out.println(">>Loader2>> "+msg); 33 } 34 35 protected Class findClass2(String name) throws ClassNotFoundException { 36 print("Fetching the implementation of "+name); 37 int old = _recur; 38 try { 39 FileInputStream fi = new FileInputStream(name+".class"); 40 byte result[] = new byte[fi.available()]; 41 fi.read(result); 42 43 print("DefineClass1 on "+name); 44 _recur++; 45 Class clazz = defineClass(name, result, 0, result.length); 46 _recur = old; 47 print("Returning newly loaded class."); 48 return clazz; 49 } catch (Exception e) { 50 _recur = old; 51 print("Not found on disk."); 52 // If we caught an exception, either the class was not found or 53 // it was unreadable by our process. 54 return null; 55 //throw new ClassNotFoundException(e.toString()); 56 } 57 } 58 59 protected synchronized Class loadClass(String name, boolean resolve) throws ClassNotFoundException { 60 // Attempt a disk load first 61 Class c = findClass2(name); 62 if( c == null ) { 63 // check if the class has already been loaded 64 print("Checking for prior loaded class "+name); 65 c = findLoadedClass(name); 66 print("Letting super-loader load "+name); 67 int old = _recur; 68 _recur++; 69 c = super.loadClass(name, false); 70 _recur=old; 71 } 72 if (resolve) { print("Resolving class "+name); resolveClass(c); } 73 print("Returning clazz "+c.getClassLoader()+":"+name); 74 return c; 75 } 76 }