content: /*
   * Copyright (c) OSGi Alliance (2008, 2009). All Rights Reserved.
   *
   * 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.osgi.service.blueprint.container;
  
  import org.osgi.framework.ServiceException;
  
  /**
   * A Blueprint exception indicating that a service is unavailable.
   * 
   * This exception is thrown when an invocation is made on a service reference
   * and a backing service is not available.
   * 
   * @version $Revision$
   */
  public class ServiceUnavailableException extends ServiceException {
  	private static final long	serialVersionUID	= 1L;
  	/**
  	 * The filter string associated with the exception.
  	 */
  	private final String		filter;
  
  	/**
  	 * Creates a Service Unavailable Exception with the specified message.
  	 * 
  	 * @param message The associated message.
  	 * @param filter The filter used for the service lookup.
  	 */
  	public ServiceUnavailableException(String message, String filter) {
  		super(message, UNREGISTERED);
  		this.filter = filter;
  	}
  
  	/**
  	 * Creates a Service Unavailable Exception with the specified message and
  	 * exception cause.
  	 * 
  	 * @param message The associated message.
  	 * @param filter The filter used for the service lookup.
  	 * @param cause The cause of this exception.
  	 */
  	public ServiceUnavailableException(String message, String filter,
  			Throwable cause) {
  		super(message, UNREGISTERED, cause);
  		this.filter = filter;
  	}
  
  	/**
  	 * Returns the filter expression that a service would have needed to satisfy
  	 * in order for the invocation to proceed.
  	 * 
  	 * @return The failing filter.
  	 */
  	public String getFilter() {
  		return this.filter;
  	}
  }
  