001/*
002 * #%L
003 * Netarchivesuite - common
004 * %%
005 * Copyright (C) 2005 - 2014 The Royal Danish Library, the Danish State and University Library,
006 *             the National Library of France and the Austrian National Library.
007 * %%
008 * This program is free software: you can redistribute it and/or modify
009 * it under the terms of the GNU Lesser General Public License as
010 * published by the Free Software Foundation, either version 2.1 of the
011 * License, or (at your option) any later version.
012 * 
013 * This program is distributed in the hope that it will be useful,
014 * but WITHOUT ANY WARRANTY; without even the implied warranty of
015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
016 * GNU General Lesser Public License for more details.
017 * 
018 * You should have received a copy of the GNU General Lesser Public
019 * License along with this program.  If not, see
020 * <http://www.gnu.org/licenses/lgpl-2.1.html>.
021 * #L%
022 */
023package dk.netarkivet.common.utils.batch;
024
025import java.io.File;
026
027import dk.netarkivet.common.exceptions.ArgumentNotValid;
028import dk.netarkivet.common.utils.FileUtils;
029
030/**
031 * A subclass of ClassLoader that can take a byte[] containing a class file.
032 */
033public class ByteClassLoader extends ClassLoader {
034
035    /** Binary class data loaded from file. */
036    private final byte[] binaryData;
037
038    /**
039     * Constructor that reads data from a file.
040     *
041     * @param binaryFile A file containing a Java class.
042     */
043    public ByteClassLoader(File binaryFile) {
044        ArgumentNotValid.checkNotNull(binaryFile, "File binaryFile");
045        this.binaryData = FileUtils.readBinaryFile(binaryFile);
046    }
047
048    /**
049     * Constructor taking a class as an array of bytes.
050     *
051     * @param bytes Array of bytes containing a class definition.
052     */
053    public ByteClassLoader(byte[] bytes) {
054        ArgumentNotValid.checkNotNull(bytes, "byte[] bytes");
055        this.binaryData = bytes;
056    }
057
058    /**
059     * Define the class that this class loader knows about. The name of the class is taken from the data given in the
060     * constructor.
061     * <p>
062     * Note that this does *not* override any of the java.lang.ClassLoader#defineClass methods. Calling this method
063     * directly is the only way to get the class defined by this classloader.
064     *
065     * @return A new Class object for this class.
066     */
067    @SuppressWarnings("rawtypes")
068    public Class defineClass() {
069        return super.defineClass(null, binaryData, 0, binaryData.length);
070    }
071
072}