import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.collect.Iterables;
-import java.lang.reflect.Constructor;
-import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;
+import java.util.Optional;
import java.util.concurrent.Callable;
import java.util.function.Function;
import java.util.function.Supplier;
private static final Splitter DOT_SPLITTER = Splitter.on('.');
private ClassLoaderUtils() {
- throw new UnsupportedOperationException("Utility class");
+ // Hidden on purpose
}
/**
}
}
- /**
- * Runs {@link Supplier} with provided {@link ClassLoader}.
- *
- * <p>
- * Invokes supplies function and makes sure that original {@link ClassLoader}
- * is context {@link ClassLoader} after execution.
- *
- * @param cls {@link ClassLoader} to be used.
- * @param function Function to be executed.
- * @return Result of supplier invocation.
- *
- * @deprecated Use {@link #getWithClassLoader(ClassLoader, Supplier)} instead.
- */
- @Deprecated
- public static <V> V withClassLoader(final ClassLoader cls, final Supplier<V> function) {
- return getWithClassLoader(cls, function);
- }
-
- /**
- * Runs {@link Callable} with provided {@link ClassLoader}.
- *
- * <p>
- * Invokes supplies function and makes sure that original {@link ClassLoader}
- * is context {@link ClassLoader} after execution.
- *
- * @param cls {@link ClassLoader} to be used.
- * @param function Function to be executed.
- * @return Result of callable invocation.
- *
- * @deprecated Use {@link #callWithClassLoader(ClassLoader, Callable)} instead.
- */
- @Deprecated
- public static <V> V withClassLoader(final ClassLoader cls, final Callable<V> function) throws Exception {
- return callWithClassLoader(cls, function);
- }
-
- // FIXME: 3.0.0: Remove or improve this to be an explicit cast to a receiver <T>?
- public static Object construct(final Constructor<?> constructor, final List<Object> objects)
- throws InstantiationException, IllegalAccessException, InvocationTargetException {
- final Object[] initargs = objects.toArray();
- return constructor.newInstance(initargs);
- }
-
/**
* Loads class using this supplied classloader.
*
return loadClass(tccl, name);
}
- // FIXME: 3.0.0: Document and return Optional
- public static Class<?> tryToLoadClassWithTCCL(final String fullyQualifiedClassName) {
+ public static Optional<Class<?>> tryToLoadClassWithTCCL(final String fullyQualifiedClassName) {
final Thread thread = Thread.currentThread();
final ClassLoader tccl = thread.getContextClassLoader();
if (tccl == null) {
LOG.debug("Thread {} does not have a Context Class Loader, not loading class {}", thread,
fullyQualifiedClassName);
- return null;
+ return Optional.empty();
}
try {
- return loadClass(tccl, fullyQualifiedClassName);
+ return Optional.of(loadClass(tccl, fullyQualifiedClassName));
} catch (final ClassNotFoundException e) {
LOG.debug("Failed to load class {}", fullyQualifiedClassName, e);
- return null;
+ return Optional.empty();
}
}
@SuppressWarnings("unchecked")
- public static <S, G, P> Class<P> findFirstGenericArgument(final Class<S> scannedClass, final Class<G> genericType) {
+ public static <S, G, P> Optional<Class<P>> findFirstGenericArgument(final Class<S> scannedClass,
+ final Class<G> genericType) {
return getWithClassLoader(scannedClass.getClassLoader(), () -> {
- final ParameterizedType augmentationGeneric = findParameterizedType(scannedClass, genericType);
- return augmentationGeneric != null ? (Class<P>) augmentationGeneric.getActualTypeArguments()[0] : null;
+ return findParameterizedType(scannedClass, genericType)
+ .map(ptype -> (Class<P>) ptype.getActualTypeArguments()[0]);
});
}
- // FIXME: 3.0.0: Document and return Optional
- public static ParameterizedType findParameterizedType(final Class<?> subclass, final Class<?> genericType) {
- requireNonNull(subclass);
+ /**
+ * Find the parameterized instantiation of a particular interface implemented by a class.
+ *
+ * @param subclass Implementing class
+ * @param genericType Interface to search for
+ * @return Parameterized interface as implemented by the class, if present
+ */
+ public static Optional<ParameterizedType> findParameterizedType(final Class<?> subclass,
+ final Class<?> genericType) {
requireNonNull(genericType);
for (final Type type : subclass.getGenericInterfaces()) {
- if (type instanceof ParameterizedType && genericType.equals(((ParameterizedType) type).getRawType())) {
- return (ParameterizedType) type;
+ if (type instanceof ParameterizedType) {
+ final ParameterizedType ptype = (ParameterizedType) type;
+ if (genericType.equals(ptype.getRawType())) {
+ return Optional.of(ptype);
+ }
}
}
LOG.debug("Class {} does not declare interface {}", subclass, genericType);
- return null;
+ return Optional.empty();
}
- // FIXME: 3.0.0: Document and return Optional
- public static Type getFirstGenericParameter(final Type type) {
- if (type instanceof ParameterizedType) {
- return ((ParameterizedType) type).getActualTypeArguments()[0];
- }
- return null;
+ /**
+ * Extract the first generic type argument for a Type. If the type is not parameterized, this method returns empty.
+ *
+ * @param type Type to examine
+ * @return First generic type argument, if present
+ * @throws NullPointerException if {@code type} is null
+ */
+ public static Optional<Type> getFirstGenericParameter(final Type type) {
+ requireNonNull(type);
+ return type instanceof ParameterizedType ? Optional.of(((ParameterizedType) type).getActualTypeArguments()[0])
+ : Optional.empty();
}
}
Code Review / yangtools.git / blobdiff