net.zcarioca.zcommons.config.source.spi.DefaultConfigSourceServiceProvider.java Source code

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Here is the source code for net.zcarioca.zcommons.config.source.spi.DefaultConfigSourceServiceProvider.java

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/*
 * Project: zlib-config
 * 
 * Copyright (C) 2010 zcarioca.net
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package net.zcarioca.zcommons.config.source.spi;

import static net.zcarioca.zcommons.config.ConfigurationConstants.DEFAULT_CONFIGURATION_SOURCE_SERVICE_PROVIDER;

import java.io.InputStream;
import java.util.Properties;

import net.zcarioca.zcommons.config.exceptions.ConfigurationException;
import net.zcarioca.zcommons.config.source.ConfigurationSourceIdentifier;
import net.zcarioca.zcommons.config.source.ConfigurationSourceProvider;
import net.zcarioca.zcommons.config.util.PropertiesBuilder;

import org.apache.commons.io.IOUtils;

/**
 * A classpath based implementation of the {@link ConfigurationSourceProvider}
 * interface.
 * 
 * @author zcarioca
 */
public class DefaultConfigSourceServiceProvider extends AbstractConfigurationSourceServiceProvider
        implements ConfigurationSourceProvider {
    public String getProviderID() {
        return DEFAULT_CONFIGURATION_SOURCE_SERVICE_PROVIDER;
    }

    /**
     * This provider is marked as a BACKUP provider.
     * 
     * {@inheritDoc}
     */
    @Override
    public Priority getPriorityLevel() {
        return Priority.BACKUP;
    }

    @Override
    protected String getResourceName(ConfigurationSourceIdentifier configurationSourceIdentifier) {
        String resourceName = super.getResourceName(configurationSourceIdentifier);
        if (!resourceName.endsWith(".properties") && !resourceName.endsWith(".xml")) {
            resourceName = resourceName + ".properties";
        }
        return resourceName;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean supportsIdentifier(ConfigurationSourceIdentifier configurationSourceIdentifier) {
        return true;
    }

    @Override
    protected Properties buildPropertiesFromValidInputs(Class<?> referenceClass, String resourceName,
            PropertiesBuilder propertiesBuilder) throws ConfigurationException {
        InputStream in = null;
        try {
            in = getResourceAsStream(referenceClass, resourceName);
            return propertiesBuilder.readAll(in).build();
        } catch (Throwable t) {
            throw new ConfigurationException(
                    String.format("Could not read configuration for %s using the reference class %s", resourceName,
                            referenceClass),
                    t);
        } finally {
            IOUtils.closeQuietly(in);
        }
    }

    private InputStream getResourceAsStream(Class<?> referenceClass, String resourceName) {
        InputStream in = referenceClass.getResourceAsStream(resourceName);
        if (in == null) {
            in = Thread.currentThread().getContextClassLoader().getResourceAsStream(resourceName);
        }
        return in;
    }
}