/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
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 */
package org.hibernate.bytecode.spi;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.ZipInputStream;

A helper for reading byte code from various input sources.
Author:Steve Ebersole
/** * A helper for reading byte code from various input sources. * * @author Steve Ebersole */
public class ByteCodeHelper {
Disallow instantiation (its a helper)
/** * Disallow instantiation (its a helper) */
private ByteCodeHelper() { }
Reads class byte array info from the given input stream. The stream is closed within this method!
Params:
  • inputStream – The stream containing the class binary; null will lead to an IOException
Throws:
  • IOException – Indicates a problem accessing the given stream.
Returns:The read bytes
/** * Reads class byte array info from the given input stream. * * The stream is closed within this method! * * @param inputStream The stream containing the class binary; null will lead to an {@link IOException} * * @return The read bytes * * @throws IOException Indicates a problem accessing the given stream. */
public static byte[] readByteCode(InputStream inputStream) throws IOException { if ( inputStream == null ) { throw new IOException( "null input stream" ); } final byte[] buffer = new byte[409600]; byte[] classBytes = new byte[0]; try { int r = inputStream.read( buffer ); while ( r >= buffer.length ) { final byte[] temp = new byte[ classBytes.length + buffer.length ]; // copy any previously read bytes into the temp array System.arraycopy( classBytes, 0, temp, 0, classBytes.length ); // copy the just read bytes into the temp array (after the previously read) System.arraycopy( buffer, 0, temp, classBytes.length, buffer.length ); classBytes = temp; // read the next set of bytes into buffer r = inputStream.read( buffer ); } if ( r != -1 ) { final byte[] temp = new byte[ classBytes.length + r ]; // copy any previously read bytes into the temp array System.arraycopy( classBytes, 0, temp, 0, classBytes.length ); // copy the just read bytes into the temp array (after the previously read) System.arraycopy( buffer, 0, temp, classBytes.length, r ); classBytes = temp; } } finally { try { inputStream.close(); } catch (IOException ignore) { // intentionally empty } } return classBytes; }
Read class definition from a file.
Params:
  • file – The file to read.
Throws:
  • IOException – Indicates a problem accessing the given stream.
Returns:The class bytes
/** * Read class definition from a file. * * @param file The file to read. * * @return The class bytes * * @throws IOException Indicates a problem accessing the given stream. */
public static byte[] readByteCode(File file) throws IOException { return ByteCodeHelper.readByteCode( new FileInputStream( file ) ); }
Read class definition a zip (jar) file entry.
Params:
  • zip – The zip entry stream.
Throws:
  • IOException – Indicates a problem accessing the given stream.
Returns:The class bytes
/** * Read class definition a zip (jar) file entry. * * @param zip The zip entry stream. * * @return The class bytes * * @throws IOException Indicates a problem accessing the given stream. */
public static byte[] readByteCode(ZipInputStream zip) throws IOException { final ByteArrayOutputStream bout = new ByteArrayOutputStream(); final InputStream in = new BufferedInputStream( zip ); int b; while ( ( b = in.read() ) != -1 ) { bout.write( b ); } return bout.toByteArray(); } }