/*

  * Copyright 2011-2012 smartics, Kronseder & Reiner GmbH

  *

  * 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 de.smartics.util.adapt;

 /**

  * Signals that an implementation is not adaptable to the desired type.

  */

 public final class AdaptableException extends RuntimeException

 {

   // ********************************* Fields *********************************

   // --- constants ------------------------------------------------------------

   /**

    * The class version identifier.

    * <p>

    * The value of this constant is {@value}.

    */

   private static final long serialVersionUID = 1L;

   // --- members --------------------------------------------------------------

   /**

    * The type of the instance that does not provide the requested adapter. May

    * be <code>null</code>.

    *

    * @serial

    */

   private final Class<?> instanceType;

   /**

    * The type of the requested adapter the instance cannot provided. May be

    * <code>null</code>.

    *

    * @serial

    */

   private final Class<?> adapterType;

   // ****************************** Initializer *******************************

   // ****************************** Constructors ******************************

   /**

    * Convenience constructor without a root cause.

    *

    * @param instanceType the type of the instance that does not provide the

    *          requested adapter.

    * @param adapterType the type of the requested adapter the instance cannot

    *          provided.

    */

   public AdaptableException(final Class<?> instanceType,

       final Class<?> adapterType)

   {

     this(null, instanceType, adapterType);

   }

   /**

    * Default constructor.

    *

    * @param cause the root cause to this exception.

    * @param instanceType the type of the instance that does not provide the

    *          requested adapter.

    * @param adapterType the type of the requested adapter the instance cannot

    *          provided.

    */

   public AdaptableException(final Throwable cause, final Class<?> instanceType,

       final Class<?> adapterType)

   {

     super(createMessage(instanceType, adapterType), cause);

     this.instanceType = instanceType;

     this.adapterType = adapterType;

   }

   // ****************************** Inner Classes *****************************

   // ********************************* Methods ********************************

   // --- init -----------------------------------------------------------------

   private static String createMessage(final Class<?> instanceType,

       final Class<?> adapterType)

   {

     final StringBuilder buffer = new StringBuilder(128);

     if (instanceType != null)

     {

       buffer.append(instanceType.getName());

     }

     else

     {

       buffer.append("Instance of unknown type");

     }

     buffer.append(" cannot be assigned to ");

     if (adapterType != null)

     {

       buffer.append(adapterType.getName());

     }

     else

     {

       buffer.append("unknown type");

     }

     buffer.append('.');

     return buffer.toString();

   }

   // --- get&set --------------------------------------------------------------

   /**

    * Returns the type of the instance that does not provide the requested

    * adapter.

    *

    * @return the type of the instance that does not provide the requested

    *         adapter. May be <code>null</code>.

    */

   public Class<?> getInstanceType()

   {

     return instanceType;

   }

   /**

    * Returns the type of the requested adapter the instance cannot provided.

    *

    * @return the type of the requested adapter the instance cannot provided. May

    *         be <code>null</code>.

    */

   public Class<?> getAdapterType()

   {

     return adapterType;

   }

   // --- business -------------------------------------------------------------

   // --- object basics --------------------------------------------------------

 }