HierarchicType.java

/*
 * 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.wink.common.internal.type;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

/**
 * Simple replacement for {@link java.lang.Class} (and/or various Type subtypes)
 * that is used as part of single-path extends/implements chain to express
 * specific relationship between one subtype and one supertype. This is needed
 * for resolving type parameters. Instances are doubly-linked so that chain
 * can be traversed in both directions
 * 
 * @since 1.6
 */
public class HierarchicType {
    /**
     * Type which will be either plain {@link java.lang.Class} or
     * {@link java.lang.reflect.ParameterizedType}.
     */
    protected final Type _actualType;

    protected final Class<?> _rawClass;

    protected final ParameterizedType _genericType;

    protected HierarchicType _superType;

    protected HierarchicType _subType;

    public HierarchicType(Type type) {
        this._actualType = type;
        if (type instanceof Class<?>) {
            _rawClass = (Class<?>)type;
            _genericType = null;
        } else if (type instanceof ParameterizedType) {
            _genericType = (ParameterizedType)type;
            _rawClass = (Class<?>)_genericType.getRawType();
        } else { // should never happen... can't extend GenericArrayType?
            throw new IllegalArgumentException("Type " + type.getClass().getName()
                + " can not be used to construct HierarchicType");
        }
    }

    public void setSuperType(HierarchicType sup) {
        _superType = sup;
    }

    public HierarchicType getSuperType() {
        return _superType;
    }

    public void setSubType(HierarchicType sub) {
        _subType = sub;
    }

    public HierarchicType getSubType() {
        return _subType;
    }

    public boolean isGeneric() {
        return _genericType != null;
    }

    public ParameterizedType asGeneric() {
        return _genericType;
    }

    public Class<?> getRawClass() {
        return _rawClass;
    }

    @Override
    public String toString() {
        if (_genericType != null) {
            return _genericType.toString();
        }
        return _rawClass.getName();
    }

}