PredefinedTermListFactory.java

package com.browseengine.bobo.facets.data;

import java.lang.reflect.Constructor;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * Class supported:
 * <ul>
 * <li> {@link Integer}</li>
 * <li> {@link Float}</li>
 * <li> {@link Character}</li>
 * <li> {@link Double}</li>
 * <li> {@link Short}</li>
 * <li> {@link Long}</li>
 * <li> {@link Date}</li>
 * </ul>
 *
 * Autoboxing: primitive types corresponding classes above are supported.
 */
public class PredefinedTermListFactory<T> implements TermListFactory<T> {
  private static Map<Class<?>, Class<? extends TermValueList<?>>> supportedTypes = new HashMap<Class<?>, Class<? extends TermValueList<?>>>();

  static {
    supportedTypes.put(int.class, TermIntList.class);
    supportedTypes.put(float.class, TermFloatList.class);
    supportedTypes.put(char.class, TermCharList.class);
    supportedTypes.put(double.class, TermDoubleList.class);
    supportedTypes.put(short.class, TermShortList.class);
    supportedTypes.put(long.class, TermLongList.class);
    supportedTypes.put(Integer.class, TermIntList.class);
    supportedTypes.put(Float.class, TermFloatList.class);
    supportedTypes.put(Character.class, TermCharList.class);
    supportedTypes.put(Double.class, TermDoubleList.class);
    supportedTypes.put(Short.class, TermShortList.class);
    supportedTypes.put(Long.class, TermLongList.class);
    supportedTypes.put(Date.class, TermDateList.class);
  }

  private final Class<T> _cls;
  private final String _format;
  private final Class<? extends TermValueList<T>> _listClass;

  @SuppressWarnings("unchecked")
  public PredefinedTermListFactory(Class<T> cls, String format) {
    if (supportedTypes.get(cls) == null) {
      throw new IllegalArgumentException("Class " + cls + " not defined.");
    }
    _cls = cls;
    _format = format;
    _listClass = (Class<? extends TermValueList<T>>) supportedTypes.get(_cls);
  }

  public PredefinedTermListFactory(Class<T> cls) {
    this(cls, null);
  }

  @Override
  public TermValueList<T> createTermList(int capacity) {
    if (TermCharList.class.equals(_listClass)) // we treat char type separate as
                                               // it does not have a format
                                               // string
    {
      @SuppressWarnings("unchecked")
      TermValueList<T> retlist = (TermValueList<T>) (new TermCharList(capacity));
      ;
      return retlist;
    } else {
      try {
        Constructor<? extends TermValueList<T>> constructor = _listClass.getConstructor(int.class,
          String.class); // the constructor also takes the format String as parameter
        return constructor.newInstance(capacity, _format);
      } catch (Exception e) {
        throw new RuntimeException(e.getMessage());
      }
    }
  }

  @Override
  public TermValueList<T> createTermList() {
    return createTermList(-1);
  }

  @Override
  public Class<T> getType() {
    // TODO Auto-generated method stub
    return _cls;
  }
}