CollectionType.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;

/**
 * Type that represents Java Collection types (Lists, Sets).
 */
public final class CollectionType extends TypeBase {
    /**
     * Type of elements in collection
     */
    final JavaType _elementType;

    /*
    /**********************************************************
    /* Life-cycle
    /**********************************************************
     */

    private CollectionType(Class<?> collT, JavaType elemT) {
        super(collT, elemT.hashCode());
        _elementType = elemT;
    }

    @Override
    protected JavaType _narrow(Class<?> subclass) {
        return new CollectionType(subclass, _elementType);
    }

    @Override
    public JavaType narrowContentsBy(Class<?> contentClass) {
        // Can do a quick check first:
        if (contentClass == _elementType.getRawClass()) {
            return this;
        }
        JavaType newElementType = _elementType.narrowBy(contentClass);
        return new CollectionType(_class, newElementType).copyHandlers(this);
    }

    public static CollectionType construct(Class<?> rawType, JavaType elemT) {
        // nominally component types will be just Object.class
        return new CollectionType(rawType, elemT);
    }

    // Since 1.7:
    @Override
    public CollectionType withTypeHandler(Object h) {
        CollectionType newInstance = new CollectionType(_class, _elementType);
        newInstance._typeHandler = h;
        return newInstance;
    }

    // Since 1.7:
    @Override
    public CollectionType withContentTypeHandler(Object h) {
        return new CollectionType(_class, _elementType.withTypeHandler(h));
    }

    @Override
    protected String buildCanonicalName() {
        StringBuilder sb = new StringBuilder();
        sb.append(_class.getName());
        if (_elementType != null) {
            sb.append('<');
            sb.append(_elementType.toCanonical());
            sb.append('>');
        }
        return sb.toString();
    }

    /*
    /**********************************************************
    /* Public API
    /**********************************************************
     */

    @Override
    public JavaType getContentType() {
        return _elementType;
    }

    @Override
    public int containedTypeCount() {
        return 1;
    }

    @Override
    public JavaType containedType(int index) {
        return (index == 0) ? _elementType : null;
    }

    /**
     * Not sure if we should count on this, but type names
     * for core interfaces use "E" for element type
     */
    @Override
    public String containedTypeName(int index) {
        if (index == 0)
            return "E";
        return null;
    }

    @Override
    public StringBuilder getErasedSignature(StringBuilder sb) {
        return _classSignature(_class, sb, true);
    }

    @Override
    public StringBuilder getGenericSignature(StringBuilder sb) {
        _classSignature(_class, sb, false);
        sb.append('<');
        _elementType.getGenericSignature(sb);
        sb.append(">;");
        return sb;
    }

    /*
    /**********************************************************
    /* Extended API
    /**********************************************************
     */

    @Override
    public boolean isContainerType() {
        return true;
    }

    /*
    /**********************************************************
    /* Standard methods
    /**********************************************************
     */

    @Override
    public String toString() {
        return "[collection type; class " + _class.getName() + ", contains " + _elementType + "]";
    }

    @Override
    public boolean equals(Object o) {
        if (o == this)
            return true;
        if (o == null)
            return false;
        if (o.getClass() != getClass())
            return false;

        CollectionType other = (CollectionType)o;
        return (_class == other._class) && _elementType.equals(other._elementType);
    }
}