+++ /dev/null
-/*
- * Copyright (C) 2011 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 com.google.gson.InstanceCreator;
-import com.google.gson.JsonIOException;
-import com.google.gson.reflect.TypeToken;
-
-import java.lang.reflect.Constructor;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.ParameterizedType;
-import java.lang.reflect.Type;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.EnumSet;
-import java.util.LinkedHashMap;
-import java.util.LinkedHashSet;
-import java.util.LinkedList;
-import java.util.Map;
-import java.util.Queue;
-import java.util.Set;
-import java.util.SortedMap;
-import java.util.SortedSet;
-import java.util.TreeMap;
-import java.util.TreeSet;
-
-/**
- * Returns a function that can construct an instance of a requested type.
- */
-public final class ConstructorConstructor {
- private final Map<Type, InstanceCreator<?>> instanceCreators;
-
- public ConstructorConstructor(Map<Type, InstanceCreator<?>> instanceCreators) {
- this.instanceCreators = instanceCreators;
- }
-
- public <T> ObjectConstructor<T> get(TypeToken<T> typeToken) {
- final Type type = typeToken.getType();
- final Class<? super T> rawType = typeToken.getRawType();
-
- // first try an instance creator
-
- @SuppressWarnings("unchecked") // types must agree
- final InstanceCreator<T> typeCreator = (InstanceCreator<T>) instanceCreators.get(type);
- if (typeCreator != null) {
- return new ObjectConstructor<T>() {
- public T construct() {
- return typeCreator.createInstance(type);
- }
- };
- }
-
- // Next try raw type match for instance creators
- @SuppressWarnings("unchecked") // types must agree
- final InstanceCreator<T> rawTypeCreator =
- (InstanceCreator<T>) instanceCreators.get(rawType);
- if (rawTypeCreator != null) {
- return new ObjectConstructor<T>() {
- public T construct() {
- return rawTypeCreator.createInstance(type);
- }
- };
- }
-
- ObjectConstructor<T> defaultConstructor = newDefaultConstructor(rawType);
- if (defaultConstructor != null) {
- return defaultConstructor;
- }
-
- ObjectConstructor<T> defaultImplementation = newDefaultImplementationConstructor(type, rawType);
- if (defaultImplementation != null) {
- return defaultImplementation;
- }
-
- // finally try unsafe
- return newUnsafeAllocator(type, rawType);
- }
-
- private <T> ObjectConstructor<T> newDefaultConstructor(Class<? super T> rawType) {
- try {
- final Constructor<? super T> constructor = rawType.getDeclaredConstructor();
- if (!constructor.isAccessible()) {
- constructor.setAccessible(true);
- }
- return new ObjectConstructor<T>() {
- @SuppressWarnings("unchecked") // T is the same raw type as is requested
- public T construct() {
- try {
- Object[] args = null;
- return (T) constructor.newInstance(args);
- } catch (InstantiationException e) {
- // TODO: JsonParseException ?
- throw new RuntimeException("Failed to invoke " + constructor + " with no args", e);
- } catch (InvocationTargetException e) {
- // TODO: don't wrap if cause is unchecked!
- // TODO: JsonParseException ?
- throw new RuntimeException("Failed to invoke " + constructor + " with no args",
- e.getTargetException());
- } catch (IllegalAccessException e) {
- throw new AssertionError(e);
- }
- }
- };
- } catch (NoSuchMethodException e) {
- return null;
- }
- }
-
- /**
- * Constructors for common interface types like Map and List and their
- * subytpes.
- */
- @SuppressWarnings("unchecked") // use runtime checks to guarantee that 'T' is what it is
- private <T> ObjectConstructor<T> newDefaultImplementationConstructor(
- final Type type, Class<? super T> rawType) {
- if (Collection.class.isAssignableFrom(rawType)) {
- if (SortedSet.class.isAssignableFrom(rawType)) {
- return new ObjectConstructor<T>() {
- public T construct() {
- return (T) new TreeSet<Object>();
- }
- };
- } else if (EnumSet.class.isAssignableFrom(rawType)) {
- return new ObjectConstructor<T>() {
- @SuppressWarnings("rawtypes")
- public T construct() {
- if (type instanceof ParameterizedType) {
- Type elementType = ((ParameterizedType) type).getActualTypeArguments()[0];
- if (elementType instanceof Class) {
- return (T) EnumSet.noneOf((Class)elementType);
- } else {
- throw new JsonIOException("Invalid EnumSet type: " + type.toString());
- }
- } else {
- throw new JsonIOException("Invalid EnumSet type: " + type.toString());
- }
- }
- };
- } else if (Set.class.isAssignableFrom(rawType)) {
- return new ObjectConstructor<T>() {
- public T construct() {
- return (T) new LinkedHashSet<Object>();
- }
- };
- } else if (Queue.class.isAssignableFrom(rawType)) {
- return new ObjectConstructor<T>() {
- public T construct() {
- return (T) new LinkedList<Object>();
- }
- };
- } else {
- return new ObjectConstructor<T>() {
- public T construct() {
- return (T) new ArrayList<Object>();
- }
- };
- }
- }
-
- if (Map.class.isAssignableFrom(rawType)) {
- if (SortedMap.class.isAssignableFrom(rawType)) {
- return new ObjectConstructor<T>() {
- public T construct() {
- return (T) new TreeMap<Object, Object>();
- }
- };
- } else if (type instanceof ParameterizedType && !(String.class.isAssignableFrom(
- TypeToken.get(((ParameterizedType) type).getActualTypeArguments()[0]).getRawType()))) {
- return new ObjectConstructor<T>() {
- public T construct() {
- return (T) new LinkedHashMap<Object, Object>();
- }
- };
- } else {
- return new ObjectConstructor<T>() {
- public T construct() {
- return (T) new LinkedTreeMap<String, Object>();
- }
- };
- }
- }
-
- return null;
- }
-
- private <T> ObjectConstructor<T> newUnsafeAllocator(
- final Type type, final Class<? super T> rawType) {
- return new ObjectConstructor<T>() {
- private final UnsafeAllocator unsafeAllocator = UnsafeAllocator.create();
- @SuppressWarnings("unchecked")
- public T construct() {
- try {
- Object newInstance = unsafeAllocator.newInstance(rawType);
- return (T) newInstance;
- } catch (Exception e) {
- throw new RuntimeException(("Unable to invoke no-args constructor for " + type + ". "
- + "Register an InstanceCreator with Gson for this type may fix this problem."), e);
- }
- }
- };
- }
-
- @Override public String toString() {
- return instanceCreators.toString();
- }
-}
projects / unical.git / blobdiff