AgencyIdSupport.java

/**
 * Copyright (C) 2011 Brian Ferris <bdferris@onebusaway.org>
 *
 * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
 *
 * 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.onebusaway.federations.annotations;

import org.onebusaway.exceptions.InvalidArgumentServiceException;

/**
 * Support parsing out the agencyId from an "agencyId_entityId" string
 * representation.
 * 
 * @author bdferris
 */
public class AgencyIdSupport {
  /**
   * @param entityId
   * @return the agencyId from an "agencyId_entityId" string representation
   * @throws InvalidArgumentServiceException on a parse error
   */
  public static String getAgencyIdFromEntityId(String entityId)
      throws InvalidArgumentServiceException {
    int index = entityId.indexOf('_');
    if (index == -1)
      throw new InvalidArgumentServiceException("entityId", "badEntityId");
    return entityId.substring(0, index);
  }
}