com.anrisoftware.resources.binary.resources.BinaryResourceImpl Maven / Gradle / Ivy

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Contains the modules of the project.
There is a newer version: 4.7.0
/*
 * Copyright 2012-2014 Erwin Müller 
 *
 * This file is part of resources-binary.
 *
 * resources-binary is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * resources-binary 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 Lesser General Public License
 * along with resources-binary. If not, see .
 */
package com.anrisoftware.resources.binary.resources;

import static org.apache.commons.io.IOUtils.readFully;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Serializable;
import java.net.URL;
import java.util.Locale;

import javax.inject.Inject;

import org.apache.commons.lang3.builder.ToStringBuilder;

import com.anrisoftware.resources.api.ResourcesException;
import com.anrisoftware.resources.binary.api.BinaryResource;
import com.google.inject.assistedinject.Assisted;

/**
 * Binary resource with lazy loading.
 * 
 * @author Erwin Mueller, [email protected]
 * @since 1.0
 */
class BinaryResourceImpl implements BinaryResource, Serializable {

	/**
	 * @since 1.0
	 */
	private static final long serialVersionUID = -1207420120451049084L;

	private final BinaryResourceImplLogger log;

	private final String name;

	private final Locale locale;

	private final URL url;

	private byte[] buffer;

	/**
	 * Sets the name, locale and URL of the binary resource.
	 * 
	 * @param logger
	 *            the {@link BinaryResourceImplLogger} for logging messages.
	 * 
	 * @param name
	 *            the name of the resource.
	 * 
	 * @param locale
	 *            the {@link Locale} of the resource.
	 * 
	 * @param url
	 *            the {@link URL} of the resource.
	 */
	@Inject
	BinaryResourceImpl(BinaryResourceImplLogger logger, @Assisted String name,
			@Assisted Locale locale, @Assisted URL url) {
		this.log = logger;
		this.name = name;
		this.locale = locale;
		this.url = url;
	}

	@Override
	public String getName() {
		return name;
	}

	@Override
	public Locale getLocale() {
		return locale;
	}

	@Override
	public URL getURL() {
		return url;
	}

	@Override
	public byte[] getBinary() throws ResourcesException {
		lazyLoadBuffer();
		return buffer;
	}

	private byte[] lazyLoadBuffer() {
		if (buffer != null) {
			return buffer;
		}
		InputStream stream = getStream();
		buffer = createBufferWithStreamSize(stream);
		readStreamToBuffer(stream, buffer);
		log.loadedBuffer(this);
		return buffer;
	}

	private byte[] createBufferWithStreamSize(InputStream stream) {
		try {
			return new byte[stream.available()];
		} catch (IOException e) {
			throw log.errorReadStreamToBuffer(e, this);
		}
	}

	private void readStreamToBuffer(InputStream stream, byte[] buffer) {
		try {
			readFully(stream, buffer);
		} catch (IOException e) {
			throw log.errorReadStreamToBuffer(e, this);
		}
	}

	@Override
	public InputStream getStream() throws ResourcesException {
		if (buffer == null) {
			return openStream();
		} else {
			return new ByteArrayInputStream(buffer);
		}
	}

	private InputStream openStream() {
		try {
			return url.openStream();
		} catch (IOException e) {
			throw log.errorOpenStream(e, this);
		}
	}

	@Override
	public void discardBinary() throws ResourcesException {
		buffer = null;
	}

	@Override
	public String toString() {
		return new ToStringBuilder(this).append(name).append("locale", locale)
				.append("url", url).toString();
	}
}