net.sourceforge.javadpkg.io.impl.DataFileTarget Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of dpkg Show documentation
The library for reading and writing Debian Packages.
There is a newer version: 1.0.5
/*
 * dpkg - Debian Package library and the Debian Package Maven plugin
 * (c) Copyright 2016 Gerrit Hohl
 *
 * 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package net.sourceforge.javadpkg.io.impl;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.OutputStream;

import net.sourceforge.javadpkg.io.DataTarget;
import net.sourceforge.javadpkg.io.Streams;

/**
 * 
 * A {@link DataTarget} implementation based on a file.
 * 
 *
 * @author Gerrit Hohl ([email protected])
 * @version 1.0, 28.04.2016 by Gerrit Hohl
 */
public class DataFileTarget implements DataTarget {


	/** The file. */
	private File					file;
	/** The stream. */
	private OutputStream			out;
	/**
	 * 
	 * The public stream which is returned by the {@link #getOutputStream()}
	 * method.
	 * 
	 */
	private UncloseableOutputStream	publicOut;
	/** The name of the source. */
	private String					name;
	/** The flag if the stream is already open. */
	private boolean					opened;
									
									
	/**
	 * 
	 * Creates a source.
	 * 
	 * 
	 * The stream on the file will be opened the first time the
	 * {@link #getOutputStream()} method is called.
	 * 
	 *
	 * @param file
	 *            The file.
	 * @throws IllegalArgumentException
	 *             If the file is null.
	 */
	public DataFileTarget(File file) {
		super();
		
		if (file == null)
			throw new IllegalArgumentException("Argument file is null.");
			
		this.file = file;
		this.out = null;
		this.publicOut = null;
		this.name = file.getAbsolutePath();
		this.opened = false;
	}
	
	
	@Override
	public String getName() {
		return this.name;
	}


	/**
	 * 
	 * Creates the {@link OutputStream} which is returned by the
	 * {@link #getOutputStream()} method.
	 * 
	 */
	private void createPublicOutputStream() {
		this.publicOut = new UncloseableOutputStream(this.out, new DelegateCloseHandler(this));
	}


	/**
	 * 
	 * Ensures that the stream is opened.
	 * 
	 *
	 * @throws IOException
	 *             If an error occurs while opening the stream or if the source
	 *             is already closed.
	 */
	private void ensureOutputStream() throws IOException {
		if (this.out == null) {
			if (!this.opened) {
				try {
					this.out = Streams.createBufferedFileOutputStream(this.file);
				} catch (FileNotFoundException e) {
					throw new IOException("Couldn't open stream on target |" + this.name + "|: " + e.getMessage());
				}
				this.createPublicOutputStream();
			} else
				throw new IOException("The stream of target |" + this.name + "| is already closed.");
		}
	}


	@Override
	public OutputStream getOutputStream() throws IOException {
		this.ensureOutputStream();
		return this.publicOut;
	}
	
	
	@Override
	public void close() throws IOException {
		try {
			if (this.out != null) {
				this.out.close();
			}
		} finally {
			this.publicOut = null;
			this.out = null;
		}
	}
	
}