| /* |
| * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| import java.util.*; |
| import java.io.*; |
| |
| public class PreemptingClassLoader extends ClassLoader { |
| |
| private final Set<String> names = new HashSet<>(); |
| boolean checkLoaded = true; |
| |
| public PreemptingClassLoader(String... names) { |
| for (String n : names) this.names.add(n); |
| } |
| |
| public PreemptingClassLoader(String name, String[] names) { |
| super(name, ClassLoader.getSystemClassLoader()); |
| for (String n : names) this.names.add(n); |
| } |
| |
| public PreemptingClassLoader(String name, String[] names, boolean cL) { |
| super(name, ClassLoader.getSystemClassLoader()); |
| for (String n : names) this.names.add(n); |
| checkLoaded = cL; |
| } |
| |
| protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException { |
| if (!names.contains(name)) return super.loadClass(name, resolve); |
| Class<?> result = checkLoaded ? findLoadedClass(name) : null; |
| if (result == null) { |
| String filename = name.replace('.', '/') + ".class"; |
| try (InputStream data = getResourceAsStream(filename)) { |
| if (data == null) throw new ClassNotFoundException(); |
| try (ByteArrayOutputStream buffer = new ByteArrayOutputStream()) { |
| int b; |
| do { |
| b = data.read(); |
| if (b >= 0) buffer.write(b); |
| } while (b >= 0); |
| byte[] bytes = buffer.toByteArray(); |
| result = defineClass(name, bytes, 0, bytes.length); |
| } |
| } catch (IOException e) { |
| throw new ClassNotFoundException("Error reading class file", e); |
| } |
| } |
| if (resolve) resolveClass(result); |
| return result; |
| } |
| |
| } |