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.Arrays;
  11 import java.util.List;
  12
  13 import com.google.common.base.Joiner;
  14 import com.google.common.base.Optional;
  15
  16 public final class ClassLoaderUtils {
  17
  18     private ClassLoaderUtils() {
  19         throw new UnsupportedOperationException("Utility class");
  20     }
  21
  22     public static <V> V withClassLoader(ClassLoader cls, Callable<V> function) throws Exception {
  23         return withClassLoaderAndLock(cls, Optional.<Lock> absent(), function);
  24     }
  25
  26     public static <V> V withClassLoaderAndLock(ClassLoader cls, Lock lock, Callable<V> function) throws Exception {
  27         checkNotNull(lock, "Lock should not be null");
  28         return withClassLoaderAndLock(cls, Optional.of(lock), function);
  29     }
  30
  31     public static <V> V withClassLoaderAndLock(ClassLoader cls, Optional<Lock> lock, Callable<V> function)
  32             throws Exception {
  33         checkNotNull(cls, "Classloader should not be null");
  34         checkNotNull(function, "Function should not be null");
  35         if (lock.isPresent()) {
  36             lock.get().lock();
  37         }
  38         ClassLoader oldCls = Thread.currentThread().getContextClassLoader();
  39         try {
  40             Thread.currentThread().setContextClassLoader(cls);
  41             return function.call();
  42         } finally {
  43             Thread.currentThread().setContextClassLoader(oldCls);
  44             if (lock.isPresent()) {
  45                 lock.get().unlock();
  46             }
  47         }
  48     }
  49
  50     public static Object construct(Constructor<? extends Object> constructor, List<Object> objects)
  51             throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
  52         Object[] initargs = objects.toArray(new Object[] {});
  53         return constructor.newInstance(initargs);
  54     }
  55
  56     public static Class<?> loadClassWithTCCL(String name) throws ClassNotFoundException {
  57         if ("byte[]".equals(name)) {
  58             return byte[].class;
  59         } else if("char[]".equals(name)) {
  60             return char[].class;
  61         }
  62         try {
  63             return Thread.currentThread().getContextClassLoader().loadClass(name);
  64         } catch (ClassNotFoundException e) {
  65             String[] components = name.split("\\.");
  66             String potentialOuter;
  67             int length = components.length;
  68             if (length > 2 && (potentialOuter = components[length - 2]) != null && Character.isUpperCase(potentialOuter.charAt(0))) {
  69
  70                     String outerName = Joiner.on(".").join(Arrays.asList(components).subList(0, length - 1));
  71                     String innerName = outerName + "$" + components[length-1];
  72                     return Thread.currentThread().getContextClassLoader().loadClass(innerName);
  73             } else {
  74                 throw e;
  75             }
  76         }
  77     }
  78
  79     public static Class<?> tryToLoadClassWithTCCL(String fullyQualifiedName) {
  80         try {
  81             return loadClassWithTCCL(fullyQualifiedName);
  82         } catch (ClassNotFoundException e) {
  83             return null;
  84         }
  85     }
  86 }