https://github.com/Terracotta-OSS/statistics: A statistics framework used inside Ehcache and the Terracotta products 
/*
 * All content copyright Terracotta, Inc., unless otherwise indicated.
 *
 * 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 org.terracotta.context.extractor;

import java.lang.reflect.Field;

abstract class FieldAttributeGetter<T> implements AttributeGetter<T> {

  private final Field field;

  FieldAttributeGetter(Field field) {
    field.setAccessible(true);
    this.field = field;
  }

  abstract Object target();

  @Override
  @SuppressWarnings("unchecked")
  public T get() {
    try {
      return (T) field.get(target());
    } catch (IllegalArgumentException | IllegalAccessException ex) {
      throw new RuntimeException(ex);
    }
  }
}