blueprint-core/src/main/java/org/apache/aries/blueprint/di/ValueRecipe.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.aries.blueprint.di;

import java.lang.reflect.Type;
import java.util.Collections;
import java.util.List;

import org.osgi.service.blueprint.container.ComponentDefinitionException;
import org.osgi.service.blueprint.reflect.ValueMetadata;

/**
 * This recipe will be used to create an object from a ValueMetadata.
 * We need to keep the reference to the ValueMetadata so that we can lazily retrieve
 * the value, allowing for placeholders or such to be used at the last moment.
 *
 * @version $Rev: 820286 $, $Date: 2009-09-30 15:45:55 +0100 (Wed, 30 Sep 2009) $
 */
public class ValueRecipe extends AbstractRecipe {

    private final ValueMetadata value;
    private final Object type;

    public ValueRecipe(String name, ValueMetadata value, Object type) {
        super(name);
        this.value = value;
        this.type = type;
    }

    public List<Recipe> getDependencies() {
        return Collections.emptyList();
    }

    @Override
    protected Object internalCreate() throws ComponentDefinitionException {
        try {
            Type type = Object.class;
            if (this.type instanceof Type) {
                type = (Type) this.type;
            } else if (this.type instanceof String) {
                type = loadClass((String) this.type);
            }
            return convert(value.getStringValue(), type);
        } catch (Exception e) {            
            throw new ComponentDefinitionException(e);
        }
    }

    @Override
    public String toString() {
        return "ValueRecipe[" +
                "name='" + name + '\'' +
                ", value=" + value +
                ", type=" + type +
                ']';
    }

}