Bug 156338 [Acceptance]Exception thrown when set prefix interval to 2
Description:Exception thrown when set prefix interval to 2 Steps to reproduce: preview the attached reports and set prefix interval of group to 2 Expected result: It works properly. Actula result: When setting the prefix interval to 2 exception thrown but it worked properly while the prefix interval was 1 Error log: org.eclipse.birt.report.service.api.ReportServiceException: Error happened while running the report
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/group/StringGroupCalculator.java
/*******************************************************************************
 * Copyright (c) 2004, 2005 Actuate Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *  Actuate Corporation  - initial API and implementation
 *******************************************************************************/
package org.eclipse.birt.data.engine.impl.group;
import org.eclipse.birt.core.exception.BirtException;
/**
 * This calculator is used to calculate a string group key basing group
 * interval.
 */
class StringGroupCalculator extends GroupCalculator