src/main/java/org/osgi/util/converter/ConverterBuilderImpl.java

/*
 * Copyright (c) OSGi Alliance (2017). All Rights Reserved.
 *
 * 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 org.osgi.util.converter;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author $Id$
 */
class ConverterBuilderImpl implements ConverterBuilder {
	private final InternalConverter					converter;
	private final Map<Type,List<ConverterFunction>>	rules			= new HashMap<>();
	private final List<ConverterFunction>			catchAllRules	= new ArrayList<>();
	private final List<ConverterFunction>			errorHandlers	= new ArrayList<>();

	public ConverterBuilderImpl(InternalConverter c) {
		this.converter = c;
	}

	@Override
	public InternalConverter build() {
		return new CustomConverterImpl(converter, rules, catchAllRules,
				errorHandlers);
	}

	@Override
	public ConverterBuilder errorHandler(ConverterFunction func) {
		errorHandlers.add(func);
		return this;
	}

	@Override
	public ConverterBuilder rule(ConverterFunction func) {
		catchAllRules.add(func);
		return this;
	}

	@Override
	public ConverterBuilder rule(Type t, ConverterFunction func) {
		getRulesList(t).add(func);
		return this;
	}

	@Override
	public ConverterBuilder rule(TargetRule rule) {
		Type type = rule.getTargetType();
		getRulesList(type).add(rule.getFunction());

		if (type instanceof ParameterizedType) {
			ParameterizedType pt = (ParameterizedType) type;

			boolean containsWildCard = false;
			for (Type t : pt.getActualTypeArguments()) {
				if (t instanceof WildcardType) {
					containsWildCard = true;
					break;
				}
			}

			// If the parameterized type is a wildcard (e.g. '?') then register
			// also the raw
			// type for the rule. I.e Class<?> will also be registered under
			// bare Class.
			if (containsWildCard)
				getRulesList(pt.getRawType()).add(rule.getFunction());
		}

		return this;
	}

	private List<ConverterFunction> getRulesList(Type type) {
		List<ConverterFunction> l = rules.get(type);
		if (l == null) {
			l = new ArrayList<>();
			rules.put(type, l);
		}
		return l;
	}
}