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    1   /**
    2    * Copyright (c) 2002-2011 "Neo Technology,"
    3    * Network Engine for Objects in Lund AB [http://neotechnology.com]
    4    *
    5    * This file is part of Neo4j.
    6    *
    7    * Neo4j is free software: you can redistribute it and/or modify
    8    * it under the terms of the GNU General Public License as published by
    9    * the Free Software Foundation, either version 3 of the License, or
    10   * (at your option) any later version.
    11   *
    12   * This program is distributed in the hope that it will be useful,
    13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    15   * GNU General Public License for more details.
    16   *
    17   * You should have received a copy of the GNU General Public License
    18   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    19   */
    20  package org.neo4j.server.plugins;
    21
    22  import java.lang.reflect.InvocationTargetException;
    23  import java.lang.reflect.Method;
    24
    25  import org.neo4j.kernel.AbstractGraphDatabase;
    26  import org.neo4j.server.rest.repr.BadInputException;
    27  import org.neo4j.server.rest.repr.Representation;
    28
    29  class PluginMethod extends PluginPoint
    30  {
    31      private final ServerPlugin plugin;
    32      private final Method method;
    33      private final DataExtractor[] extractors;
    34      private final ResultConverter result;
    35
    36      PluginMethod( String name, Class<?> discovery, ServerPlugin plugin,
    37                    ResultConverter result, Method method, DataExtractor[] extractors,
    38                    Description description )
    39      {
    40          super( discovery, name, description == null ? "" : description.value() );
    41          this.plugin = plugin;
    42          this.result = result;
    43          this.method = method;
    44          this.extractors = extractors;
    45      }
    46
    47
    48
    49
    50
    51      @Override
    52      public Representation invoke( AbstractGraphDatabase graphDb, Object source, ParameterList params )
    53              throws BadPluginInvocationException, PluginInvocationFailureException,
    54              BadInputException
    55      {
    56          Object[] arguments = new Object[extractors.length];
    57          for ( int i = 0; i < arguments.length; i++ )
    58          {
    59              arguments[i] = extractors[i].extract( graphDb, source, params );
    60          }
    61          try
    62          {
    63              Object returned = method.invoke( plugin, arguments );
    64
    65              if ( returned == null )
    66              {
    67                  return Representation.emptyRepresentation();
    68              } else
    69              {
    70                  return result.convert( returned );
    71              }
    72          }
    73          catch ( InvocationTargetException exc )
    74          {
    75              Throwable targetExc = exc.getTargetException();
    76              for ( Class<?> excType : method.getExceptionTypes() )
    77              {
    78                  if ( excType.isInstance( targetExc ) )
    79                      throw new BadPluginInvocationException( targetExc );
    80              }
    81              throw new PluginInvocationFailureException( targetExc );
    82          }
    83          catch ( IllegalArgumentException e )
    84          {
    85              throw new PluginInvocationFailureException( e );
    86          }
    87          catch ( IllegalAccessException e )
    88          {
    89              throw new PluginInvocationFailureException( e );
    90          }
    91      }
    92
    93      @Override
    94      protected void describeParameters( ParameterDescriptionConsumer consumer )
    95      {
    96          for ( DataExtractor extractor : extractors )
    97          {
    98              extractor.describe( consumer );
    99          }
    100     }
    101
    102 }