/* | |
* Licensed to the Apache Software Foundation (ASF) under one | |
* or more contributor license agreements. See the NOTICE file | |
* distributed with this work for additional information | |
* regarding copyright ownership. The ASF licenses this file | |
* to you 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 org.apache.johnzon.jsonb.reflect; | |
import java.lang.reflect.ParameterizedType; | |
import java.lang.reflect.Type; | |
import java.lang.reflect.TypeVariable; | |
import java.util.Arrays; | |
// forked from johnzon-core to ensure the independency without creating a new module just for that | |
public class Types { | |
public ParameterizedType findParameterizedType(final Class<?> klass, final Class<?> parameterizedClass) { | |
return new ParameterizedTypeImpl(parameterizedClass, resolveArgumentTypes(klass, parameterizedClass)); | |
} | |
public Class<?> findParamType(final ParameterizedType type, final Class<?> expectedWrapper) { | |
if (type.getActualTypeArguments().length != 1) { | |
return null; | |
} | |
final Class<?> asClass = asClass(type.getRawType()); | |
if (asClass == null || !expectedWrapper.isAssignableFrom(asClass)) { | |
return null; | |
} | |
return asClass(type.getActualTypeArguments()[0]); | |
} | |
public Class<?> asClass(final Type type) { | |
return Class.class.isInstance(type) ? Class.class.cast(type) : null; | |
} | |
private Type[] resolveArgumentTypes(final Type type, final Class<?> parameterizedClass) { | |
if (type instanceof Class<?>) { | |
return resolveArgumentTypes((Class<?>) type, parameterizedClass); | |
} | |
if (type instanceof ParameterizedType) { | |
return resolveArgumentTypes((ParameterizedType) type, parameterizedClass); | |
} | |
throw new IllegalArgumentException("Cannot resolve argument types from " + type.getClass().getSimpleName()); | |
} | |
private Type[] resolveArgumentTypes(final Class<?> type, final Class<?> parameterizedClass) { | |
if (parameterizedClass.equals(type)) { | |
// May return Class[] instead of Type[], so copy it as a Type[] to avoid | |
// problems in visit(ParameterizedType) | |
return Arrays.copyOf(type.getTypeParameters(), parameterizedClass.getTypeParameters().length, Type[].class); | |
} | |
if (type.getSuperclass() != null && parameterizedClass.isAssignableFrom(type.getSuperclass())) { | |
return resolveArgumentTypes(type.getGenericSuperclass(), parameterizedClass); | |
} | |
Class<?>[] interfaces = type.getInterfaces(); | |
Type[] genericInterfaces = type.getGenericInterfaces(); | |
for (int i = 0; i < interfaces.length; i++) { | |
if (parameterizedClass.isAssignableFrom(interfaces[i])) { | |
return resolveArgumentTypes(genericInterfaces[i], parameterizedClass); | |
} | |
} | |
throw new IllegalArgumentException(String.format("%s is not assignable from %s", type, parameterizedClass)); | |
} | |
private Type[] resolveArgumentTypes(final ParameterizedType type, final Class<?> parameterizedClass) { | |
final Class<?> rawType = (Class<?>) type.getRawType(); // always a Class | |
final TypeVariable<?>[] typeVariables = rawType.getTypeParameters(); | |
final Type[] types = resolveArgumentTypes(rawType, parameterizedClass); | |
for (int i = 0; i < types.length; i++) { | |
if (types[i] instanceof TypeVariable<?>) { | |
TypeVariable<?> typeVariable = (TypeVariable<?>) types[i]; | |
for (int j = 0; j < typeVariables.length; j++) { | |
if (typeVariables[j].getName().equals(typeVariable.getName())) { | |
types[i] = type.getActualTypeArguments()[j]; | |
} | |
} | |
} | |
} | |
return types; | |
} | |
private static class ParameterizedTypeImpl implements ParameterizedType { | |
private final Type rawType; | |
private final Type[] arguments; | |
private ParameterizedTypeImpl(final Type rawType, final Type... arguments) { | |
this.rawType = rawType; | |
this.arguments = arguments; | |
} | |
@Override | |
public Type getRawType() { | |
return rawType; | |
} | |
@Override | |
public Type getOwnerType() { | |
return null; | |
} | |
@Override | |
public Type[] getActualTypeArguments() { | |
return arguments; | |
} | |
@Override | |
public int hashCode() { | |
return Arrays.hashCode(arguments) ^ (rawType == null ? 0 : rawType.hashCode()); | |
} | |
@Override | |
public boolean equals(final Object obj) { | |
if (this == obj) { | |
return true; | |
} | |
if (obj instanceof ParameterizedType) { | |
final ParameterizedType that = (ParameterizedType) obj; | |
final Type thatRawType = that.getRawType(); | |
return that.getOwnerType() == null | |
&& (rawType == null ? thatRawType == null : rawType.equals(thatRawType)) | |
&& Arrays.equals(arguments, that.getActualTypeArguments()); | |
} | |
return false; | |
} | |
@Override | |
public String toString() { | |
final StringBuilder buffer = new StringBuilder(); | |
buffer.append(((Class<?>) rawType).getSimpleName()); | |
final Type[] actualTypes = getActualTypeArguments(); | |
if (actualTypes.length > 0) { | |
buffer.append("<"); | |
int length = actualTypes.length; | |
for (int i = 0; i < length; i++) { | |
buffer.append(actualTypes[i].toString()); | |
if (i != actualTypes.length - 1) { | |
buffer.append(","); | |
} | |
} | |
buffer.append(">"); | |
} | |
return buffer.toString(); | |
} | |
} | |
} |