net.sourceforge.javadpkg.impl.Md5SumsBuilderImpl 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.impl;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.List;

import net.sourceforge.javadpkg.BuildException;
import net.sourceforge.javadpkg.GlobalConstants;
import net.sourceforge.javadpkg.Md5SumsBuilder;
import net.sourceforge.javadpkg.io.DataTarget;
import net.sourceforge.javadpkg.store.DataStore;
import net.sourceforge.javadpkg.store.FileHash;


/**
 * 
 * A {@link Md5SumsBuilder} implementation.
 * 
 *
 * @author Gerrit Hohl ([email protected])
 * @version 1.0, 26.04.2016 by Gerrit Hohl
 */
public class Md5SumsBuilderImpl implements Md5SumsBuilder, GlobalConstants {
	
	
	/**
	 * 
	 * Creates a builder.
	 * 
	 */
	public Md5SumsBuilderImpl() {
		super();
	}
	
	
	@Override
	public void buildMD5Sums(DataStore store, DataTarget target) throws IOException, BuildException {
		MessageDigest digest;
		List fileHashes;
		String path;


		if (store == null)
			throw new IllegalArgumentException("Argument store is null.");
		if (target == null)
			throw new IllegalArgumentException("Argument target is null.");

		// --- Create the digest ---
		try {
			digest = MessageDigest.getInstance("MD5");
		} catch (NoSuchAlgorithmException e) {
			throw new BuildException("Couldn't build MD5 sums: MD5 is not supported: " + e.getMessage(), e);
		}

		// --- Create hashes ---
		try {
			fileHashes = store.createFileHashes(digest);
		} catch (IOException e) {
			throw new IOException("Couldn't build MD5 sums: Couldn't create hashes: " + e.getMessage(), e);
		}

		// --- Write hashes ---
		try {
			try (BufferedWriter out = new BufferedWriter(new OutputStreamWriter(target.getOutputStream(), UTF_8_CHARSET))) {
				for (FileHash fileHash : fileHashes) {
					out.write(fileHash.getHashAsHex());
					out.write(" ");

					path = fileHash.getPath();
					if (path.startsWith("/")) {
						path = path.substring(1);
					}
					out.write(path);
					out.write("\n");
				}
			}
		} catch (IOException e) {
			throw new IOException("Couldn't build MD5 sums: Couldn't write MD5 sums: " + e.getMessage(), e);
		}
	}


}