com.solab.iso8583.impl.SimpleTraceGenerator Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of j8583 Show documentation

Java implementation of the ISO 8583 protocol, focused on making the creation, edition and reading of ISO8583 messages as simple and flexible as possible.

There is a newer version: 2.0.0

Show newest version

/*
j8583 A Java implementation of the ISO8583 protocol
Copyright (C) 2007 Enrique Zamudio Lopez

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.

This library 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 library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
*/
package com.solab.iso8583.impl;

import com.solab.iso8583.TraceNumberGenerator;

/** Simple implementation of a TraceNumberGenerator with an internal
 * number that is increased in memory but is not stored anywhere.
 * 
 * @author Enrique Zamudio
 */
public class SimpleTraceGenerator implements TraceNumberGenerator {

	private volatile int value = 0;

	/** Creates a new instance that will use the specified initial value. This means
	 * the first nextTrace() call will return this number.
	 * @param initialValue a number between 1 and 999999.
	 * @throws IllegalArgumentException if the number is less than 1 or greater than 999999. */
	public SimpleTraceGenerator(int initialValue) {
		if (initialValue < 1 || initialValue > 999999) {
			throw new IllegalArgumentException("Initial value must be between 1 and 999999");
		}
		value = initialValue - 1;
	}

	public int getLastTrace() {
		return value;
	}

	/** Returns the next number in the sequence. This method is synchronized, because the counter
	 * is incremented in memory only. */
	public synchronized int nextTrace() {
		value++;
		if (value > 999999) {
			value = 1;
		}
		return value;
	}

}