code-generator/binding-generator-impl/src/main/java/org/opendaylight/yangtools/sal/binding/generator/util/ClassLoaderUtils.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.yangtools.sal.binding.generator.util;
   9
  10 import static com.google.common.base.Preconditions.checkNotNull;
  11
  12 import java.lang.reflect.Constructor;
  13 import java.lang.reflect.InvocationTargetException;
  14 import java.util.Arrays;
  15 import java.util.List;
  16 import java.util.concurrent.Callable;
  17 import java.util.concurrent.locks.Lock;
  18
  19 import com.google.common.base.Joiner;
  20 import com.google.common.base.Optional;
  21
  22 public final class ClassLoaderUtils {
  23
  24     private ClassLoaderUtils() {
  25         throw new UnsupportedOperationException("Utility class");
  26     }
  27
  28     public static <V> V withClassLoader(ClassLoader cls, Callable<V> function) throws Exception {
  29         return withClassLoaderAndLock(cls, Optional.<Lock> absent(), function);
  30     }
  31
  32     public static <V> V withClassLoaderAndLock(ClassLoader cls, Lock lock, Callable<V> function) throws Exception {
  33         checkNotNull(lock, "Lock should not be null");
  34         return withClassLoaderAndLock(cls, Optional.of(lock), function);
  35     }
  36
  37     public static <V> V withClassLoaderAndLock(ClassLoader cls, Optional<Lock> lock, Callable<V> function)
  38             throws Exception {
  39         checkNotNull(cls, "Classloader should not be null");
  40         checkNotNull(function, "Function should not be null");
  41         if (lock.isPresent()) {
  42             lock.get().lock();
  43         }
  44         ClassLoader oldCls = Thread.currentThread().getContextClassLoader();
  45         try {
  46             Thread.currentThread().setContextClassLoader(cls);
  47             return function.call();
  48         } finally {
  49             Thread.currentThread().setContextClassLoader(oldCls);
  50             if (lock.isPresent()) {
  51                 lock.get().unlock();
  52             }
  53         }
  54     }
  55
  56     public static Object construct(Constructor<? extends Object> constructor, List<Object> objects)
  57             throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
  58         Object[] initargs = objects.toArray(new Object[] {});
  59         return constructor.newInstance(initargs);
  60     }
  61
  62     public static Class<?> loadClassWithTCCL(String name) throws ClassNotFoundException {
  63         if ("byte[]".equals(name)) {
  64             return byte[].class;
  65         } else if("char[]".equals(name)) {
  66             return char[].class;
  67         }
  68         try {
  69             return Thread.currentThread().getContextClassLoader().loadClass(name);
  70         } catch (ClassNotFoundException e) {
  71             String[] components = name.split("\\.");
  72             String potentialOuter;
  73             int length = components.length;
  74             if (length > 2 && (potentialOuter = components[length - 2]) != null && Character.isUpperCase(potentialOuter.charAt(0))) {
  75
  76                     String outerName = Joiner.on(".").join(Arrays.asList(components).subList(0, length - 1));
  77                     String innerName = outerName + "$" + components[length-1];
  78                     return Thread.currentThread().getContextClassLoader().loadClass(innerName);
  79             } else {
  80                 throw e;
  81             }
  82         }
  83     }
  84
  85     public static Class<?> tryToLoadClassWithTCCL(String fullyQualifiedName) {
  86         try {
  87             return loadClassWithTCCL(fullyQualifiedName);
  88         } catch (ClassNotFoundException e) {
  89             return null;
  90         }
  91     }
  92 }