MapOfValuesConverter.java :  » MongoDB » morphia » com » google » code » morphia » converters » Java Open Source

/**
 * 
 */
package com.google.code.morphia.converters;

import java.util.HashMap;
import java.util.Map;

import com.google.code.morphia.mapping.MappedField;
import com.google.code.morphia.mapping.MappingException;
import com.google.code.morphia.utils.ReflectionUtils;

/**
 * @author Uwe Schaefer, (us@thomas-daily.de)
 */
@SuppressWarnings({"unchecked","rawtypes"})
public class MapOfValuesConverter extends TypeConverter {
  private final DefaultConverters converters;
  
  public MapOfValuesConverter(DefaultConverters converters) {
    this.converters = converters;
  }
  
  @Override
  protected boolean isSupported(Class<?> c, MappedField optionalExtraInfo) {
    if (optionalExtraInfo != null)
      return optionalExtraInfo.isMap();
    else
      return ReflectionUtils.implementsInterface(c, Map.class);
  }
  
  @Override
  public Object decode(Class targetClass, Object fromDBObject, MappedField mf) throws MappingException {
    if (fromDBObject == null) return null;

    Map<Object, Object> map = (Map<Object, Object>) fromDBObject;
    Map values = mapr.getOptions().objectFactory.createMap(mf);
    for (Map.Entry<Object, Object> entry : map.entrySet()) {
      Object objKey = converters.decode(mf.getMapKeyClass(), entry.getKey());
      values.put(objKey, converters.decode(mf.getSubClass(), entry.getValue()));
    }
    return values;
  }
  
  @Override
  public Object encode(Object value, MappedField mf) {
    if (value == null)
      return null;
    
    Map<Object, Object> map = (Map<Object, Object>) value;
    if ((map != null) && (map.size() > 0)) {
      Map mapForDb = new HashMap();
      for (Map.Entry<Object, Object> entry : map.entrySet()) {
        String strKey = converters.encode(entry.getKey()).toString();
        mapForDb.put(strKey, converters.encode(entry.getValue()));
      }
      return mapForDb;
    }
    return null;
  }  
}