Hibernate example source code file (Helper.java)

This example Hibernate source code file (Helper.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

address_bytes, address_bytes, address_hex_string, address_int, helper, jvm_identifier_bytes, jvm_identifier_hex_string, jvm_identifier_int, jvm_identifier_int, net, network, string, string, stringbuffer, stringbuffer, unknownhostexception

The Hibernate Helper.java source code

/*
 * 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
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.id.uuid;

import java.net.InetAddress;
import java.net.UnknownHostException;
import org.hibernate.internal.util.BytesHelper;

/**
 * TODO : javadoc
 *
 * @author Steve Ebersole
 */
public class Helper {

	// IP ADDRESS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	private static final byte[] ADDRESS_BYTES;
	private static final int ADDRESS_INT;
	private static final String ADDRESS_HEX_STRING;

	static {
		byte[] address;
		try {
			address = InetAddress.getLocalHost().getAddress();
		}
		catch ( Exception e ) {
			address = new byte[4];
		}
		ADDRESS_BYTES = address;
		ADDRESS_INT = BytesHelper.toInt( ADDRESS_BYTES );
		ADDRESS_HEX_STRING = format( ADDRESS_INT );
	}

	public static byte[] getAddressBytes() {
		return ADDRESS_BYTES;
	}

	public static int getAddressInt() {
		return ADDRESS_INT;
	}

	public static String getAddressHexString() {
		return ADDRESS_HEX_STRING;
	}


	// JVM identifier ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	private static final byte[] JVM_IDENTIFIER_BYTES;
	private static final int JVM_IDENTIFIER_INT;
	private static final String JVM_IDENTIFIER_HEX_STRING;

	static {
		JVM_IDENTIFIER_INT = (int) ( System.currentTimeMillis() >>> 8 );
		JVM_IDENTIFIER_BYTES = BytesHelper.fromInt( JVM_IDENTIFIER_INT );
		JVM_IDENTIFIER_HEX_STRING = format( JVM_IDENTIFIER_INT );
	}

	public static byte[] getJvmIdentifierBytes() {
		return JVM_IDENTIFIER_BYTES;
	}

	public static int getJvmIdentifierInt() {
		return JVM_IDENTIFIER_INT;
	}

	public static String getJvmIdentifierHexString() {
		return JVM_IDENTIFIER_HEX_STRING;
	}


	// counter ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	private static short counter = (short) 0;

	/**
	 * Unique in a millisecond for this JVM instance (unless there are > Short.MAX_VALUE instances created in a
	 * millisecond)
	 */
	public static short getCountShort() {
		synchronized ( Helper.class ) {
			if ( counter < 0 ) {
				counter = 0;
			}
			return counter++;
		}
	}

	public static byte[] getCountBytes() {
		return BytesHelper.fromShort( getCountShort() );
	}


	// Helper methods ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	public static String format(int value) {
		final String formatted = Integer.toHexString( value );
		StringBuffer buf = new StringBuffer( "00000000".intern() );
		buf.replace( 8 - formatted.length(), 8, formatted );
		return buf.toString();
	}

	public static String format(short value) {
		String formatted = Integer.toHexString( value );
		StringBuffer buf = new StringBuffer( "0000" );
		buf.replace( 4 - formatted.length(), 4, formatted );
		return buf.toString();
	}


	public static void main(String[] args) throws UnknownHostException {
		byte[] addressBytes = InetAddress.getLocalHost().getAddress();
		System.out.println( "Raw ip address bytes : " + addressBytes.toString() );

		int addressInt = BytesHelper.toInt( addressBytes );
		System.out.println( "ip address int : " + addressInt );

		String formatted = Integer.toHexString( addressInt );
		StringBuffer buf = new StringBuffer( "00000000" );
		buf.replace( 8 - formatted.length(), 8, formatted );
		String addressHex = buf.toString();
		System.out.println( "ip address hex : " + addressHex );
	}
}