1 /*
   2  * Copyright (c) 2014, 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.util.ArrayList;
  26 import java.util.Arrays;
  27 import java.util.HashMap;
  28 
  29 
  30 public class ByteCodeClassLoader extends ClassLoader {
  31     ArrayList<ClassConstruct> classes = new ArrayList<>();
  32     HashMap<String, Class> loadedClasses = new HashMap<>();
  33 
  34     public void addClasses(ClassConstruct... classes) {
  35         this.classes.addAll(Arrays.asList(classes));
  36     }
  37 
  38     public void loadAll() throws ClassNotFoundException {
  39         for (ClassConstruct clazz : classes) {
  40             findClass(clazz.getDottedName());
  41         }
  42     }
  43 
  44 
  45     @Override
  46     public Class findClass(String name) throws ClassNotFoundException {
  47 
  48         Class cls = loadedClasses.get(name);
  49 
  50         if (cls != null) {
  51             return cls;
  52         }
  53 
  54         for (ClassConstruct clazz : classes) {
  55             if (clazz.getDottedName().equals(name)) {
  56                 return load(clazz);
  57             }
  58         }
  59 
  60         throw new ClassNotFoundException(name);
  61     }
  62 
  63     @Override
  64     public Class loadClass(String name) throws ClassNotFoundException {
  65         try {
  66             return findClass(name);
  67         } catch (ClassNotFoundException e) {
  68             return super.loadClass(name);
  69         }
  70     }
  71 
  72     private Class load(ClassConstruct clazz) {
  73         byte[] bytecode = clazz.generateBytes();
  74         Class loadedClass = defineClass(clazz.getDottedName(), bytecode, 0, bytecode.length);
  75         loadedClasses.put(clazz.getDottedName(), loadedClass);
  76         return loadedClass;
  77     }
  78 }