--- /dev/null
+/**
+ * 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 com.google.gson.internal;
+
+import static com.google.gson.internal.$Gson$Preconditions.checkArgument;
+import static com.google.gson.internal.$Gson$Preconditions.checkNotNull;
+
+import java.io.Serializable;
+import java.lang.reflect.Array;
+import java.lang.reflect.GenericArrayType;
+import java.lang.reflect.GenericDeclaration;
+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 java.util.Collection;
+import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Properties;
+
+/**
+ * Static methods for working with types.
+ *
+ * @author Bob Lee
+ * @author Jesse Wilson
+ */
+public final class $Gson$Types {
+ static final Type[] EMPTY_TYPE_ARRAY = new Type[] {};
+
+ private $Gson$Types() {}
+
+ /**
+ * Returns a new parameterized type, applying {@code typeArguments} to
+ * {@code rawType} and enclosed by {@code ownerType}.
+ *
+ * @return a {@link java.io.Serializable serializable} parameterized type.
+ */
+ public static ParameterizedType newParameterizedTypeWithOwner(
+ Type ownerType, Type rawType, Type... typeArguments) {
+ return new ParameterizedTypeImpl(ownerType, rawType, typeArguments);
+ }
+
+ /**
+ * Returns an array type whose elements are all instances of
+ * {@code componentType}.
+ *
+ * @return a {@link java.io.Serializable serializable} generic array type.
+ */
+ public static GenericArrayType arrayOf(Type componentType) {
+ return new GenericArrayTypeImpl(componentType);
+ }
+
+ /**
+ * Returns a type that represents an unknown type that extends {@code bound}.
+ * For example, if {@code bound} is {@code CharSequence.class}, this returns
+ * {@code ? extends CharSequence}. If {@code bound} is {@code Object.class},
+ * this returns {@code ?}, which is shorthand for {@code ? extends Object}.
+ */
+ public static WildcardType subtypeOf(Type bound) {
+ return new WildcardTypeImpl(new Type[] { bound }, EMPTY_TYPE_ARRAY);
+ }
+
+ /**
+ * Returns a type that represents an unknown supertype of {@code bound}. For
+ * example, if {@code bound} is {@code String.class}, this returns {@code ?
+ * super String}.
+ */
+ public static WildcardType supertypeOf(Type bound) {
+ return new WildcardTypeImpl(new Type[] { Object.class }, new Type[] { bound });
+ }
+
+ /**
+ * Returns a type that is functionally equal but not necessarily equal
+ * according to {@link Object#equals(Object) Object.equals()}. The returned
+ * type is {@link java.io.Serializable}.
+ */
+ public static Type canonicalize(Type type) {
+ if (type instanceof Class) {
+ Class<?> c = (Class<?>) type;
+ return c.isArray() ? new GenericArrayTypeImpl(canonicalize(c.getComponentType())) : c;
+
+ } else if (type instanceof ParameterizedType) {
+ ParameterizedType p = (ParameterizedType) type;
+ return new ParameterizedTypeImpl(p.getOwnerType(),
+ p.getRawType(), p.getActualTypeArguments());
+
+ } else if (type instanceof GenericArrayType) {
+ GenericArrayType g = (GenericArrayType) type;
+ return new GenericArrayTypeImpl(g.getGenericComponentType());
+
+ } else if (type instanceof WildcardType) {
+ WildcardType w = (WildcardType) type;
+ return new WildcardTypeImpl(w.getUpperBounds(), w.getLowerBounds());
+
+ } else {
+ // type is either serializable as-is or unsupported
+ return type;
+ }
+ }
+
+ public 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();
+ checkArgument(rawType instanceof Class);
+ 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);
+ }
+ }
+
+ static boolean equal(Object a, Object b) {
+ return a == b || (a != null && a.equals(b));
+ }
+
+ /**
+ * Returns true if {@code a} and {@code b} are equal.
+ */
+ public static boolean equals(Type a, Type b) {
+ if (a == b) {
+ // also handles (a == null && b == null)
+ return true;
+
+ } else if (a instanceof Class) {
+ // Class already specifies equals().
+ return a.equals(b);
+
+ } else if (a instanceof ParameterizedType) {
+ if (!(b instanceof ParameterizedType)) {
+ return false;
+ }
+
+ // TODO: save a .clone() call
+ ParameterizedType pa = (ParameterizedType) a;
+ ParameterizedType pb = (ParameterizedType) b;
+ return equal(pa.getOwnerType(), pb.getOwnerType())
+ && pa.getRawType().equals(pb.getRawType())
+ && Arrays.equals(pa.getActualTypeArguments(), pb.getActualTypeArguments());
+
+ } else if (a instanceof GenericArrayType) {
+ 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 type we support. Could be a generic array type, wildcard type, etc.
+ return false;
+ }
+ }
+
+ private static int hashCodeOrZero(Object o) {
+ return o != null ? o.hashCode() : 0;
+ }
+
+ public static String typeToString(Type type) {
+ return type instanceof Class ? ((Class<?>) type).getName() : type.toString();
+ }
+
+ /**
+ * Returns the generic supertype for {@code supertype}. For example, given a class {@code
+ * IntegerSet}, the result for when supertype is {@code Set.class} is {@code Set<Integer>} and the
+ * result when the supertype is {@code Collection.class} is {@code Collection<Integer>}.
+ */
+ static Type getGenericSupertype(Type context, Class<?> rawType, Class<?> toResolve) {
+ if (toResolve == rawType) {
+ return context;
+ }
+
+ // we skip searching through interfaces if unknown is an interface
+ if (toResolve.isInterface()) {
+ Class<?>[] interfaces = rawType.getInterfaces();
+ for (int i = 0, length = interfaces.length; i < length; i++) {
+ if (interfaces[i] == toResolve) {
+ return rawType.getGenericInterfaces()[i];
+ } else if (toResolve.isAssignableFrom(interfaces[i])) {
+ return getGenericSupertype(rawType.getGenericInterfaces()[i], interfaces[i], toResolve);
+ }
+ }
+ }
+
+ // check our supertypes
+ if (!rawType.isInterface()) {
+ while (rawType != Object.class) {
+ Class<?> rawSupertype = rawType.getSuperclass();
+ if (rawSupertype == toResolve) {
+ return rawType.getGenericSuperclass();
+ } else if (toResolve.isAssignableFrom(rawSupertype)) {
+ return getGenericSupertype(rawType.getGenericSuperclass(), rawSupertype, toResolve);
+ }
+ rawType = rawSupertype;
+ }
+ }
+
+ // we can't resolve this further
+ return toResolve;
+ }
+
+ /**
+ * Returns the generic form of {@code supertype}. For example, if this is {@code
+ * ArrayList<String>}, this returns {@code Iterable<String>} given the input {@code
+ * Iterable.class}.
+ *
+ * @param supertype a superclass of, or interface implemented by, this.
+ */
+ static Type getSupertype(Type context, Class<?> contextRawType, Class<?> supertype) {
+ checkArgument(supertype.isAssignableFrom(contextRawType));
+ return resolve(context, contextRawType,
+ $Gson$Types.getGenericSupertype(context, contextRawType, supertype));
+ }
+
+ /**
+ * Returns the component type of this array type.
+ * @throws ClassCastException if this type is not an array.
+ */
+ public static Type getArrayComponentType(Type array) {
+ return array instanceof GenericArrayType
+ ? ((GenericArrayType) array).getGenericComponentType()
+ : ((Class<?>) array).getComponentType();
+ }
+
+ /**
+ * Returns the element type of this collection type.
+ * @throws IllegalArgumentException if this type is not a collection.
+ */
+ public static Type getCollectionElementType(Type context, Class<?> contextRawType) {
+ Type collectionType = getSupertype(context, contextRawType, Collection.class);
+
+ if (collectionType instanceof WildcardType) {
+ collectionType = ((WildcardType)collectionType).getUpperBounds()[0];
+ }
+ if (collectionType instanceof ParameterizedType) {
+ return ((ParameterizedType) collectionType).getActualTypeArguments()[0];
+ }
+ return Object.class;
+ }
+
+ /**
+ * Returns a two element array containing this map's key and value types in
+ * positions 0 and 1 respectively.
+ */
+ public static Type[] getMapKeyAndValueTypes(Type context, Class<?> contextRawType) {
+ /*
+ * Work around a problem with the declaration of java.util.Properties. That
+ * class should extend Hashtable<String, String>, but it's declared to
+ * extend Hashtable<Object, Object>.
+ */
+ if (context == Properties.class) {
+ return new Type[] { String.class, String.class }; // TODO: test subclasses of Properties!
+ }
+
+ Type mapType = getSupertype(context, contextRawType, Map.class);
+ // TODO: strip wildcards?
+ if (mapType instanceof ParameterizedType) {
+ ParameterizedType mapParameterizedType = (ParameterizedType) mapType;
+ return mapParameterizedType.getActualTypeArguments();
+ }
+ return new Type[] { Object.class, Object.class };
+ }
+
+ public static Type resolve(Type context, Class<?> contextRawType, Type toResolve) {
+ // this implementation is made a little more complicated in an attempt to avoid object-creation
+ while (true) {
+ if (toResolve instanceof TypeVariable) {
+ TypeVariable<?> typeVariable = (TypeVariable<?>) toResolve;
+ toResolve = resolveTypeVariable(context, contextRawType, typeVariable);
+ if (toResolve == typeVariable) {
+ return toResolve;
+ }
+
+ } else if (toResolve instanceof Class && ((Class<?>) toResolve).isArray()) {
+ Class<?> original = (Class<?>) toResolve;
+ Type componentType = original.getComponentType();
+ Type newComponentType = resolve(context, contextRawType, componentType);
+ return componentType == newComponentType
+ ? original
+ : arrayOf(newComponentType);
+
+ } else if (toResolve instanceof GenericArrayType) {
+ GenericArrayType original = (GenericArrayType) toResolve;
+ Type componentType = original.getGenericComponentType();
+ Type newComponentType = resolve(context, contextRawType, componentType);
+ return componentType == newComponentType
+ ? original
+ : arrayOf(newComponentType);
+
+ } else if (toResolve instanceof ParameterizedType) {
+ ParameterizedType original = (ParameterizedType) toResolve;
+ Type ownerType = original.getOwnerType();
+ Type newOwnerType = resolve(context, contextRawType, ownerType);
+ boolean changed = newOwnerType != ownerType;
+
+ Type[] args = original.getActualTypeArguments();
+ for (int t = 0, length = args.length; t < length; t++) {
+ Type resolvedTypeArgument = resolve(context, contextRawType, args[t]);
+ if (resolvedTypeArgument != args[t]) {
+ if (!changed) {
+ args = args.clone();
+ changed = true;
+ }
+ args[t] = resolvedTypeArgument;
+ }
+ }
+
+ return changed
+ ? newParameterizedTypeWithOwner(newOwnerType, original.getRawType(), args)
+ : original;
+
+ } else if (toResolve instanceof WildcardType) {
+ WildcardType original = (WildcardType) toResolve;
+ Type[] originalLowerBound = original.getLowerBounds();
+ Type[] originalUpperBound = original.getUpperBounds();
+
+ if (originalLowerBound.length == 1) {
+ Type lowerBound = resolve(context, contextRawType, originalLowerBound[0]);
+ if (lowerBound != originalLowerBound[0]) {
+ return supertypeOf(lowerBound);
+ }
+ } else if (originalUpperBound.length == 1) {
+ Type upperBound = resolve(context, contextRawType, originalUpperBound[0]);
+ if (upperBound != originalUpperBound[0]) {
+ return subtypeOf(upperBound);
+ }
+ }
+ return original;
+
+ } else {
+ return toResolve;
+ }
+ }
+ }
+
+ static Type resolveTypeVariable(Type context, Class<?> contextRawType, TypeVariable<?> unknown) {
+ Class<?> declaredByRaw = declaringClassOf(unknown);
+
+ // we can't reduce this further
+ if (declaredByRaw == null) {
+ return unknown;
+ }
+
+ Type declaredBy = getGenericSupertype(context, contextRawType, declaredByRaw);
+ if (declaredBy instanceof ParameterizedType) {
+ int index = indexOf(declaredByRaw.getTypeParameters(), unknown);
+ return ((ParameterizedType) declaredBy).getActualTypeArguments()[index];
+ }
+
+ return unknown;
+ }
+
+ private static int indexOf(Object[] array, Object toFind) {
+ for (int i = 0; i < array.length; i++) {
+ if (toFind.equals(array[i])) {
+ return i;
+ }
+ }
+ throw new NoSuchElementException();
+ }
+
+ /**
+ * Returns the declaring class of {@code typeVariable}, or {@code null} if it was not declared by
+ * a class.
+ */
+ private static Class<?> declaringClassOf(TypeVariable<?> typeVariable) {
+ GenericDeclaration genericDeclaration = typeVariable.getGenericDeclaration();
+ return genericDeclaration instanceof Class
+ ? (Class<?>) genericDeclaration
+ : null;
+ }
+
+ private static void checkNotPrimitive(Type type) {
+ checkArgument(!(type instanceof Class<?>) || !((Class<?>) type).isPrimitive());
+ }
+
+ private static final class ParameterizedTypeImpl implements ParameterizedType, Serializable {
+ private final Type ownerType;
+ private final Type rawType;
+ private final Type[] typeArguments;
+
+ public ParameterizedTypeImpl(Type ownerType, Type rawType, Type... typeArguments) {
+ // require an owner type if the raw type needs it
+ if (rawType instanceof Class<?>) {
+ Class<?> rawTypeAsClass = (Class<?>) rawType;
+ checkArgument(ownerType != null || rawTypeAsClass.getEnclosingClass() == null);
+ checkArgument(ownerType == null || rawTypeAsClass.getEnclosingClass() != null);
+ }
+
+ this.ownerType = ownerType == null ? null : canonicalize(ownerType);
+ this.rawType = canonicalize(rawType);
+ this.typeArguments = typeArguments.clone();
+ for (int t = 0; t < this.typeArguments.length; t++) {
+ checkNotNull(this.typeArguments[t]);
+ checkNotPrimitive(this.typeArguments[t]);
+ this.typeArguments[t] = canonicalize(this.typeArguments[t]);
+ }
+ }
+
+ public Type[] getActualTypeArguments() {
+ return typeArguments.clone();
+ }
+
+ public Type getRawType() {
+ return rawType;
+ }
+
+ public Type getOwnerType() {
+ return ownerType;
+ }
+
+ @Override public boolean equals(Object other) {
+ return other instanceof ParameterizedType
+ && $Gson$Types.equals(this, (ParameterizedType) other);
+ }
+
+ @Override public int hashCode() {
+ return Arrays.hashCode(typeArguments)
+ ^ rawType.hashCode()
+ ^ hashCodeOrZero(ownerType);
+ }
+
+ @Override public String toString() {
+ StringBuilder stringBuilder = new StringBuilder(30 * (typeArguments.length + 1));
+ stringBuilder.append(typeToString(rawType));
+
+ if (typeArguments.length == 0) {
+ return stringBuilder.toString();
+ }
+
+ stringBuilder.append("<").append(typeToString(typeArguments[0]));
+ for (int i = 1; i < typeArguments.length; i++) {
+ stringBuilder.append(", ").append(typeToString(typeArguments[i]));
+ }
+ return stringBuilder.append(">").toString();
+ }
+
+ private static final long serialVersionUID = 0;
+ }
+
+ private static final class GenericArrayTypeImpl implements GenericArrayType, Serializable {
+ private final Type componentType;
+
+ public GenericArrayTypeImpl(Type componentType) {
+ this.componentType = canonicalize(componentType);
+ }
+
+ public Type getGenericComponentType() {
+ return componentType;
+ }
+
+ @Override public boolean equals(Object o) {
+ return o instanceof GenericArrayType
+ && $Gson$Types.equals(this, (GenericArrayType) o);
+ }
+
+ @Override public int hashCode() {
+ return componentType.hashCode();
+ }
+
+ @Override public String toString() {
+ return typeToString(componentType) + "[]";
+ }
+
+ private static final long serialVersionUID = 0;
+ }
+
+ /**
+ * The WildcardType interface supports multiple upper bounds and multiple
+ * lower bounds. We only support what the Java 6 language needs - at most one
+ * bound. If a lower bound is set, the upper bound must be Object.class.
+ */
+ private static final class WildcardTypeImpl implements WildcardType, Serializable {
+ private final Type upperBound;
+ private final Type lowerBound;
+
+ public WildcardTypeImpl(Type[] upperBounds, Type[] lowerBounds) {
+ checkArgument(lowerBounds.length <= 1);
+ checkArgument(upperBounds.length == 1);
+
+ if (lowerBounds.length == 1) {
+ checkNotNull(lowerBounds[0]);
+ checkNotPrimitive(lowerBounds[0]);
+ checkArgument(upperBounds[0] == Object.class);
+ this.lowerBound = canonicalize(lowerBounds[0]);
+ this.upperBound = Object.class;
+
+ } else {
+ checkNotNull(upperBounds[0]);
+ checkNotPrimitive(upperBounds[0]);
+ this.lowerBound = null;
+ this.upperBound = canonicalize(upperBounds[0]);
+ }
+ }
+
+ public Type[] getUpperBounds() {
+ return new Type[] { upperBound };
+ }
+
+ public Type[] getLowerBounds() {
+ return lowerBound != null ? new Type[] { lowerBound } : EMPTY_TYPE_ARRAY;
+ }
+
+ @Override public boolean equals(Object other) {
+ return other instanceof WildcardType
+ && $Gson$Types.equals(this, (WildcardType) other);
+ }
+
+ @Override public int hashCode() {
+ // this equals Arrays.hashCode(getLowerBounds()) ^ Arrays.hashCode(getUpperBounds());
+ return (lowerBound != null ? 31 + lowerBound.hashCode() : 1)
+ ^ (31 + upperBound.hashCode());
+ }
+
+ @Override public String toString() {
+ if (lowerBound != null) {
+ return "? super " + typeToString(lowerBound);
+ } else if (upperBound == Object.class) {
+ return "?";
+ } else {
+ return "? extends " + typeToString(upperBound);
+ }
+ }
+
+ private static final long serialVersionUID = 0;
+ }
+}
projects / unical.git / blobdiff