/**
    * Copyright 2010-2013 The Kuali Foundation
    *
    * Licensed under the Educational Community License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.opensource.org/licenses/ecl2.php
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.kuali.common.util;
  
  public class Counter {
  
  	int count;
  
  	public Counter() {
  		this(0);
  	}
  
  	public Counter(int startValue) {
  		this.count = startValue;
  	}
  
  	public synchronized int increment() {
  		return increment(1);
  	}
  
  	public synchronized int increment(int amount) {
  		Assert.isTrue(amount > 0, "amount must be > 0");
  		Assert.isTrue(count <= Integer.MAX_VALUE - amount, "max value exceeded");
  		return count += amount;
  	}
  
  	public synchronized int decrement() {
  		return decrement(1);
  	}
  
  	public synchronized int decrement(int amount) {
  		Assert.isTrue(amount > 0, "amount must be > 0");
  		Assert.isTrue(count >= Integer.MIN_VALUE + amount, "min value exceeded");
  		return count -= amount;
  	}
  
  	public synchronized int getValue() {
  		return count;
  	}
  }