/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.id.uuid;

import java.net.InetAddress;
import java.net.UnknownHostException;

import org.hibernate.internal.build.AllowSysOut;
import org.hibernate.internal.util.BytesHelper;

TODO : javadoc
Author:Steve Ebersole
/** * TODO : javadoc * * @author Steve Ebersole */
public final class Helper { private 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)
/** * 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 ); StringBuilder buf = new StringBuilder( "00000000" ); buf.replace( 8 - formatted.length(), 8, formatted ); return buf.toString(); } public static String format(short value) { String formatted = Integer.toHexString( value ); StringBuilder buf = new StringBuilder( "0000" ); buf.replace( 4 - formatted.length(), 4, formatted ); return buf.toString(); } @AllowSysOut 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 ); StringBuilder buf = new StringBuilder( "00000000" ); buf.replace( 8 - formatted.length(), 8, formatted ); String addressHex = buf.toString(); System.out.println( "ip address hex : " + addressHex ); } }