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(final ClassLoader cls, final Callable<V> function) throws Exception {
  29         checkNotNull(cls, "Classloader should not be null");
  30         checkNotNull(function, "Function should not be null");
  31
  32         final ClassLoader oldCls = Thread.currentThread().getContextClassLoader();
  33         try {
  34             Thread.currentThread().setContextClassLoader(cls);
  35             return function.call();
  36         } finally {
  37             Thread.currentThread().setContextClassLoader(oldCls);
  38         }
  39     }
  40
  41     public static <V> V withClassLoaderAndLock(final ClassLoader cls, final Lock lock, final Callable<V> function) throws Exception {
  42         checkNotNull(lock, "Lock should not be null");
  43
  44         lock.lock();
  45         try {
  46             return withClassLoader(cls, function);
  47         } finally {
  48             lock.unlock();
  49         }
  50     }
  51
  52     /**
  53      * @deprecated Use one of the other utility methods.
  54      */
  55     @Deprecated
  56     public static <V> V withClassLoaderAndLock(final ClassLoader cls, final Optional<Lock> lock, final Callable<V> function) throws Exception {
  57         if (lock.isPresent()) {
  58             return withClassLoaderAndLock(cls, lock.get(), function);
  59         } else {
  60             return withClassLoader(cls, function);
  61         }
  62     }
  63
  64     public static Object construct(final Constructor<? extends Object> constructor, final List<Object> objects)
  65             throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
  66         Object[] initargs = objects.toArray(new Object[] {});
  67         return constructor.newInstance(initargs);
  68     }
  69
  70
  71     public static Class<?> loadClass(final ClassLoader cls, final String name) throws ClassNotFoundException {
  72         if ("byte[]".equals(name)) {
  73             return byte[].class;
  74         } else if("char[]".equals(name)) {
  75             return char[].class;
  76         }
  77         try {
  78             return cls.loadClass(name);
  79         } catch (ClassNotFoundException e) {
  80             String[] components = name.split("\\.");
  81             String potentialOuter;
  82             int length = components.length;
  83             if (length > 2 && (potentialOuter = components[length - 2]) != null && Character.isUpperCase(potentialOuter.charAt(0))) {
  84
  85                     String outerName = Joiner.on(".").join(Arrays.asList(components).subList(0, length - 1));
  86                     String innerName = outerName + "$" + components[length-1];
  87                     return cls.loadClass(innerName);
  88             } else {
  89                 throw e;
  90             }
  91         }
  92     }
  93
  94     public static Class<?> loadClassWithTCCL(final String name) throws ClassNotFoundException {
  95         return loadClass(Thread.currentThread().getContextClassLoader(), name);
  96     }
  97
  98     public static Class<?> tryToLoadClassWithTCCL(final String fullyQualifiedName) {
  99         try {
 100             return loadClassWithTCCL(fullyQualifiedName);
 101         } catch (ClassNotFoundException e) {
 102             return null;
 103         }
 104     }
 105 }