我正在开发一个帮助类来使用 Lucene。它的意思是将一个对象带入一个工厂,并用一种索引对象的方法来装饰对象,根据提供的对象类型添加索引策略。代码看起来像这样:
class IndexWrapper
{
public interface IDocumentable
{
Document BuildDocument();
}
public interface IDocumentBuilder
{
Type SupportedType { get; }
Document BuildDocument(object o);
}
public class StringDocumentBuilder : IDocumentBuilder
{
public Type SupportedType { get { return typeof(string); } }
public Document BuildDocument(object o)
{
Document doc = new Document();
doc.Add(new Field("string", o as string, Field.Store.YES, Field.Index.ANALYZED));
return doc;
}
}
public static class IndexableFactory
{
public static IDocumentable GetIndexableObject(object o)
{
return GetIndexableObject(o, DocumentBuilderFactory.GetBuilder(o));
}
public static IDocumentable GetIndexableObject(object o, IDocumentBuilder builder)
{
return new IndexableObject(o, builder);
}
}
public static class DocumentBuilderFactory
{
private static List<IDocumentBuilder> _builders = new List<IDocumentBuilder>();
public static IDocumentBuilder GetBuilder(object o)
{
if (_builders.Count == 0)
{
_builders = Assembly.GetExecutingAssembly()
.GetTypes()
.Where(type => typeof(IDocumentBuilder).IsAssignableFrom(type) && type.IsClass)
.Select(type => Activator.CreateInstance(type))
.Cast<IDocumentBuilder>()
.ToList();
}
return _builders.Where(builder => builder.SupportedType.IsAssignableFrom(o.GetType())).FirstOrDefault();
}
}
private class IndexableObject : IDocumentable
{
object _o;
IDocumentBuilder _builder;
public IndexableObject(object o) : this(o, DocumentBuilderFactory.GetBuilder(o)) { }
public IndexableObject(object o, IDocumentBuilder builder)
{
_o = o;
_builder = builder;
}
virtual public Document BuildDocument()
{
return _builder.BuildDocument(_o);
}
}
}
我想知道的是:是否可以为用户最有可能看到的类类型包含一组默认策略,而不包括包含这些类的库?