package org.exolab.castor.mapping.loader.collection.handler;
   
   import java.lang.reflect.Array;
   import java.util.Enumeration;
   
   import org.exolab.castor.mapping.CollectionHandler;
   import org.exolab.castor.mapping.loader.CollectionHandlers;
   import org.exolab.castor.mapping.loader.J1CollectionHandlers.ArrayEnumerator;
   
  public final class ArrayCollectionHandler<T> implements CollectionHandler<T> {
    public Object add(Object collection, T object) {
      if (collection == null) {
  
        // If the collection is of primitive type, the instantiation
        // (if it was null) is handled in the FieldHandlerImpl. We
        // can rely here that we deal only with array of object.
        Object newArray = Array.newInstance(object.getClass(), 1);
        Array.set(newArray, 0, object);
        return newArray;
      }
  
      Class<?> type = collection.getClass();
      if (!type.isArray()) {
        String err = "J1CollectionHandlers.array#add: type "
            + "mismatch, expecting an array, instead received: ";
        err += type.getName();
        throw new IllegalArgumentException(err);
      }
  
      type = type.getComponentType();
  
      Object newArray = Array.newInstance(type, Array.getLength(collection) + 1);
  
      for (int i = 0; i < Array.getLength(collection); ++i)
        Array.set(newArray, i, Array.get(collection, i));
  
      Array.set(newArray, Array.getLength(collection), object);
  
      return newArray;
  
    }
  
    public Enumeration<T> elements(Object collection) {
      if (collection == null)
        return new CollectionHandlers.EmptyEnumerator<T>();
      return new ArrayEnumerator<T>(collection);
    }
  
    public int size(Object collection) {
      if (collection == null)
        return 0;
      return Array.getLength(collection);
    }
  
    public Object clear(Object collection) {
      if (collection == null) {
        return null;
      }
      Class<?> type = collection.getClass();
      if (!type.isArray()) {
        String err = "J1CollectionHandlers.array#add: type "
            + "mismatch, expecting an array, instead received: ";
        err += type.getName();
        throw new IllegalArgumentException(err);
      }
      type = type.getComponentType();
      return Array.newInstance(type, 0);
    }
  
    public String toString() {
      return "Object[]";
    }
  }