package org.apache.ojb.broker.metadata.fieldaccess;

 /* Copyright 2003-2005 The Apache Software Foundation

  *

  * 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.

  */

 import java.lang.reflect.Field;

 import java.util.ArrayList;

 import java.util.List;

 import org.apache.commons.lang.StringUtils;

 import org.apache.commons.lang.SystemUtils;

 import org.apache.commons.lang.builder.ToStringBuilder;

 import org.apache.ojb.broker.metadata.MetadataException;

 import org.apache.ojb.broker.util.logging.Logger;

 import org.apache.ojb.broker.util.logging.LoggerFactory;

 /**

  * Abstract {@link PersistentField} base implementation class.

  *

  * @author <a href="mailto:armin@codeAuLait.de">Armin Waibel</a>

  * @version $Id: PersistentFieldBase.java,v 1.1 2007-08-24 22:17:35 ewestfal Exp $

  */

 public abstract class PersistentFieldBase implements PersistentField

 {

     public static final String PATH_TOKEN = "::";

     private String fieldName;

     protected Class rootObjectType;

     /**

      * For internal use only!!

      * TODO: Default constructor only needed to support

      * PersistentFieldFactory#usesAccessorsAndMutators()

      * method - find a better solution. Make 'public' to

      * allow helper class to instantiate class.

      */

     public PersistentFieldBase()

     {

     }

     public PersistentFieldBase(Class clazz, String fieldname)

     {

         this.rootObjectType = clazz;

         this.fieldName = fieldname;

     }

     /**

      * A value of true indicates that this field should

      * suppress Java language access checking when it is used.

      */

     protected abstract boolean makeAccessible();

     public String getName()

     {

         return fieldName;

     }

     public Class getDeclaringClass()

     {

         return rootObjectType;

     }

     protected List getFieldGraph(boolean makeAccessible)

     {

         List result = new ArrayList();

         String[] fields = StringUtils.split(getName(), PATH_TOKEN);

         Field fld = null;

         for (int i = 0; i < fields.length; i++)

         {

             String fieldName = fields[i];

             try

             {

                 if (fld == null)

                 {

                     fld = getFieldRecursive(rootObjectType, fieldName);

                 }

                 else

                 {

                     fld = getFieldRecursive(fld.getType(), fieldName);

                 }

                 if (makeAccessible)

                 {

                     fld.setAccessible(true);

                 }

             }

             catch (NoSuchFieldException e)

             {

                 throw new MetadataException("Can't find member '"

                         + fieldName + "' in class " + (fld != null ? fld.getDeclaringClass() : rootObjectType), e);

             }

             result.add(fld);

         }

         return result;

     }

     /**

      * try to find a field in class c, recurse through class hierarchy if necessary

      *

      * @throws NoSuchFieldException if no Field was found into the class hierarchy

      */

     private Field getFieldRecursive(Class c, String name) throws NoSuchFieldException

     {

         try

         {

             return c.getDeclaredField(name);

         }

         catch (NoSuchFieldException e)

         {

             // if field  could not be found in the inheritance hierarchy, signal error

             if ((c == Object.class) || (c.getSuperclass() == null) || c.isInterface())

             {

                 throw e;

             }

             // if field could not be found in class c try in superclass

             else

             {

                 return getFieldRecursive(c.getSuperclass(), name);

             }

         }

     }

     protected Logger getLog()

     {

         return LoggerFactory.getLogger("PersistentField");

     }

     public String toString()

     {

         ToStringBuilder buf = new ToStringBuilder(this);

         buf.append("rootType", rootObjectType);

         buf.append("fieldName", fieldName);

         return buf.toString();

     }

     /**

      * Build a String representation of given arguments.

      */

     protected String buildErrorSetMsg(Object obj, Object value, Field aField)

     {

         String eol = SystemUtils.LINE_SEPARATOR;

         StringBuffer buf = new StringBuffer();

         buf

                 .append(eol + "[try to set 'object value' in 'target object'")

                 .append(eol + "target obj class: " + (obj != null ? obj.getClass().getName() : null))

                 .append(eol + "target field name: " + (aField != null ? aField.getName() : null))

                 .append(eol + "target field type: " + (aField != null ? aField.getType() : null))

                 .append(eol + "target field declared in: " + (aField != null ? aField.getDeclaringClass().getName() : null))

                 .append(eol + "object value class: " + (value != null ? value.getClass().getName() : null))

                 .append(eol + "object value: " + (value != null ? value : null))

                 .append(eol + "]");

         return buf.toString();

     }

     /**

      * Build a String representation of given arguments.

      */

     protected String buildErrorGetMsg(Object obj, Field aField)

     {

         String eol = SystemUtils.LINE_SEPARATOR;

         StringBuffer buf = new StringBuffer();

         buf

                 .append(eol + "[try to read from source object")

                 .append(eol + "source obj class: " + (obj != null ? obj.getClass().getName() : null))

                 .append(eol + "target field name: " + (aField != null ? aField.getName() : null))

                 .append(eol + "target field type: " + (aField != null ? aField.getType() : null))

                 .append(eol + "target field declared in: " + (aField != null ? aField.getDeclaringClass().getName() : null))

                 .append(eol + "]");

         return buf.toString();

     }

 }