opendaylight/md-sal/sal-binding-broker/src/main/java/org/opendaylight/controller/sal/binding/impl/util/ClassLoaderUtils.java

   1 package org.opendaylight.controller.sal.binding.impl.util;
   2
   3 import java.util.concurrent.Callable;
   4 import java.util.concurrent.locks.Lock;
   5
   6 import static com.google.common.base.Preconditions.*;
   7
   8 import java.lang.reflect.Constructor;
   9 import java.lang.reflect.InvocationTargetException;
  10 import java.util.ArrayList;
  11 import java.util.List;
  12
  13 import com.google.common.base.Optional;
  14
  15 public final class ClassLoaderUtils {
  16
  17     private ClassLoaderUtils() {
  18         throw new UnsupportedOperationException("Utility class");
  19     }
  20
  21     public static <V> V withClassLoader(ClassLoader cls, Callable<V> function) throws Exception {
  22         return withClassLoaderAndLock(cls, Optional.<Lock> absent(), function);
  23     }
  24
  25     public static <V> V withClassLoaderAndLock(ClassLoader cls, Lock lock, Callable<V> function) throws Exception {
  26         checkNotNull(lock, "Lock should not be null");
  27         return withClassLoaderAndLock(cls, Optional.of(lock), function);
  28     }
  29
  30     public static <V> V withClassLoaderAndLock(ClassLoader cls, Optional<Lock> lock, Callable<V> function)
  31             throws Exception {
  32         checkNotNull(cls, "Classloader should not be null");
  33         checkNotNull(function, "Function should not be null");
  34         if (lock.isPresent()) {
  35             lock.get().lock();
  36         }
  37         ClassLoader oldCls = Thread.currentThread().getContextClassLoader();
  38         try {
  39             Thread.currentThread().setContextClassLoader(cls);
  40             return function.call();
  41         } finally {
  42             Thread.currentThread().setContextClassLoader(oldCls);
  43             if (lock.isPresent()) {
  44                 lock.get().unlock();
  45             }
  46         }
  47     }
  48
  49     public static Object construct(Constructor<? extends Object> constructor, List<Object> objects)
  50             throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
  51         Object[] initargs = objects.toArray(new Object[] {});
  52         return constructor.newInstance(initargs);
  53     }
  54
  55     public static Class<?> loadClassWithTCCL(String name) throws ClassNotFoundException {
  56         if ("byte[]".equals(name)) {
  57             return byte[].class;
  58         }
  59
  60         return Thread.currentThread().getContextClassLoader().loadClass(name);
  61     }
  62 }