com.rapiddweller.common.accessor.AccessorMapAccessor Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of rd-lib-common Show documentation

'rapiddweller Common' is an open source Java library forked from Databene Commons by Volker Bergmann. It provides extensions to the Java core library by utility classes, abstract concepts and concrete implementations.

There is a newer version: 2.0.1-jdk-11

Show newest version

/*
 * Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
 * 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 com.rapiddweller.common.accessor;

import com.rapiddweller.common.Accessor;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * Uses an accessor which is stored in a Map for accessing the target object.
 * Created: 11.03.2006 12:45:26
 *
 * @author Volker Bergmann
 */
@SuppressWarnings({"unchecked", "rawtypes"})
public class AccessorMapAccessor implements DependentAccessor {

  private static final List> EMPTY_LIST = new ArrayList<>();

  private final Map> map;
  private final Object key;

  /**
   * Instantiates a new Accessor map accessor.
   *
   * @param map the map
   * @param key the key
   */
  public AccessorMapAccessor(Map> map, Object key) {
    this.map = map;
    this.key = key;
  }

  // interface -------------------------------------------------------------------------------------------------------

  /**
   * Gets key.
   *
   * @return the key
   */
  public Object getKey() {
    return key;
  }

  @Override
  public Object getValue(Object target) {
    Accessor accessor = getAccessor();
    if (accessor == null) {
      throw new IllegalStateException("Key not found: " + key);
    }
    return accessor.getValue(target);
  }

  @Override
  public List> getDependencies() {
    Accessor accessor = getAccessor();
    if (accessor instanceof DependentAccessor) {
      return ((DependentAccessor) accessor).getDependencies();
    } else {
      return EMPTY_LIST;
    }
  }

  /**
   * Gets accessor.
   *
   * @return the accessor
   */
  public Accessor getAccessor() {
    return map.get(key);
  }
}