org.brekka.stillingar.spring.converter.ApplicationContextConverter.java Source code

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Here is the source code for org.brekka.stillingar.spring.converter.ApplicationContextConverter.java

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/*
 * Copyright 2012 the original author or authors.
 *
 * 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.brekka.stillingar.spring.converter;

import org.brekka.stillingar.core.conversion.AbstractTypeConverter;
import org.brekka.stillingar.core.conversion.xml.DocumentConverter;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.support.GenericApplicationContext;
import org.w3c.dom.Document;

/**
 * Type converter that will parse an section of XML to produce a Spring Application Context. This will allow an
 * application to dynamically reload an application context and have it injected into a bean.
 * 
 * @author Andrew Taylor (andrew@brekka.org)
 */
public class ApplicationContextConverter extends AbstractTypeConverter<ApplicationContext>
        implements ApplicationContextAware {

    private final DocumentConverter documentConverter;

    private ApplicationContext applicationContext;

    public ApplicationContextConverter(DocumentConverter documentConverter) {
        this.documentConverter = documentConverter;
    }

    @Override
    public final Class<ApplicationContext> targetType() {
        return ApplicationContext.class;
    }

    @Override
    public ApplicationContext convert(Object obj) {
        Document document = documentConverter.convert(obj);
        GenericApplicationContext context;
        if (applicationContext == null) {
            context = new GenericApplicationContext();
        } else {
            context = new GenericApplicationContext(applicationContext);
        }
        XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(context);
        reader.registerBeanDefinitions(document, null);
        context.refresh();
        return context;
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
}