content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you 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.apache.causeway.applib.services.scratchpad;
  
  import org.springframework.beans.factory.DisposableBean;
  
  /**
   * This service (API and implementation) provides a mechanism to interchange information
   * between multiple objects invoked in the same interaction.
   *
   * @since 1.x {@index}
   */
  public interface Scratchpad
          extends DisposableBean {
  
      /**
       * Obtain user-data, as set by a previous object being acted upon.
       *
       * <p>
       *     The key value should obey the general contract for hash maps.
       * </p>
       */
      public Object get(Object key);
  
      /**
       * Set user-data, for the use of a subsequent object being acted upon.
       *
       * <p>
       *     The key value should obey the general contract for hash maps.
       * </p>
       */
      public void put(Object key, Object value);
  
  }
  