/*
* Copyright (C) 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package dagger.reflect;
import dagger.reflect.TypeUtil.ParameterizedTypeImpl;
import java.lang.reflect.Array;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.lang.reflect.WildcardType;
import java.util.Arrays;
import org.jetbrains.annotations.Nullable;
final class Types {
private Types() {}
static Class<?> getRawType(Type type) {
if (type instanceof Class<?>) {
// type is a normal class.
return (Class<?>) type;
} else if (type instanceof ParameterizedType) {
ParameterizedType parameterizedType = (ParameterizedType) type;
// I'm not exactly sure why getRawType() returns Type instead of Class. Neal isn't either but
// suspects some pathological case related to nested classes exists.
Type rawType = parameterizedType.getRawType();
return (Class<?>) rawType;
} else if (type instanceof GenericArrayType) {
Type componentType = ((GenericArrayType) type).getGenericComponentType();
return Array.newInstance(getRawType(componentType), 0).getClass();
} else if (type instanceof TypeVariable) {
// We could use the variable's bounds, but that won't work if there are multiple. having a raw
// type that's more general than necessary is okay.
return Object.class;
} else if (type instanceof WildcardType) {
return getRawType(((WildcardType) type).getUpperBounds()[0]);
} else {
String className = type == null ? "null" : type.getClass().getName();
throw new IllegalArgumentException(
"Expected a Class, ParameterizedType, or "
+ "GenericArrayType, but <"
+ type
+ "> is of type "
+ className);
}
}
/** Returns true if {@code a} and {@code b} are equal. */
static boolean equals(@Nullable Type a, @Nullable Type b) {
if (a == b) {
return true; // Also handles (a == null && b == null).
} else if (a instanceof Class) {
if (b instanceof GenericArrayType) {
return equals(
((Class<?>) a).getComponentType(), ((GenericArrayType) b).getGenericComponentType());
}
return a.equals(b); // Class already specifies equals().
} else if (a instanceof ParameterizedType) {
if (!(b instanceof ParameterizedType)) return false;
ParameterizedType pa = (ParameterizedType) a;
ParameterizedType pb = (ParameterizedType) b;
Type[] aTypeArguments =
pa instanceof ParameterizedTypeImpl
? ((ParameterizedTypeImpl) pa).typeArguments
: pa.getActualTypeArguments();
Type[] bTypeArguments =
pb instanceof ParameterizedTypeImpl
? ((ParameterizedTypeImpl) pb).typeArguments
: pb.getActualTypeArguments();
return equals(pa.getOwnerType(), pb.getOwnerType())
&& pa.getRawType().equals(pb.getRawType())
&& Arrays.equals(aTypeArguments, bTypeArguments);
} else if (a instanceof GenericArrayType) {
if (b instanceof Class) {
return equals(
((Class<?>) b).getComponentType(), ((GenericArrayType) a).getGenericComponentType());
}
if (!(b instanceof GenericArrayType)) return false;
GenericArrayType ga = (GenericArrayType) a;
GenericArrayType gb = (GenericArrayType) b;
return equals(ga.getGenericComponentType(), gb.getGenericComponentType());
} else if (a instanceof WildcardType) {
if (!(b instanceof WildcardType)) return false;
WildcardType wa = (WildcardType) a;
WildcardType wb = (WildcardType) b;
return Arrays.equals(wa.getUpperBounds(), wb.getUpperBounds())
&& Arrays.equals(wa.getLowerBounds(), wb.getLowerBounds());
} else if (a instanceof TypeVariable) {
if (!(b instanceof TypeVariable)) return false;
TypeVariable<?> va = (TypeVariable<?>) a;
TypeVariable<?> vb = (TypeVariable<?>) b;
return va.getGenericDeclaration() == vb.getGenericDeclaration()
&& va.getName().equals(vb.getName());
} else {
// This isn't a supported type.
return false;
}
}
}
