package com.easyjf.dbo;

import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import org.apache.log4j.Logger;
/**
 * 類及數據表的應射表
 * @author 蔡世友
 *
 */
public class DBMapping {
private final static Logger logger = Logger.getLogger(DBMapping.class);
private final static DBMapping dbmapping=new DBMapping();
private final static Map map=new HashMap();
public static  DBMapping getInstance()
{	
	return dbmapping;
}
public void add(String className,DBTable table)
{
	map.put(className,table);
}
public void remove(String className)
{
	map.remove(className);
}
public DBTable findTable(Class cls)
{
	DBTable table=(DBTable)map.get(cls.getName());
	if(table==null)
	{
		logger.info("找不到數據庫映射"+cls.toString()+",通過IObject的定義創建一個！");
		try{
			Object tempObj=cls.newInstance();
			if(tempObj instanceof IObject){
			table=new DBTable(((IObject)tempObj).getTableName(),((IObject)tempObj).getKeyField(),((IObject)tempObj).getKeyGenerator());
			Field[] fields=cls.getDeclaredFields();
			for(int i=0;i<fields.length;i++)
			{				
			DBField field=new DBField();
			//System.out.println(fields[i].getName());
			field.setName(fields[i].getName());
			field.setType(fields[i].getType().toString());
			table.addField(field.getName(),field);
			}
			this.add(cls.getName(),table);
			}	
		}
		catch(Exception e)
		{
			System.out.println("查詢類對應的表失敗："+e);
			e.printStackTrace();
		}		
	}
	
	//System.out.println("字段數："+table.getPoperty("cid")+table.getFields().size());
	if(table==null)logger.error("無法找到類"+cls.toString()+"所映射的關系表，請通確保配置文件中具有該類的配置信息或者"+cls.toString()+"實現IObject接口");
	return table;
}

public Map getMap() {
	return map;
}
public String findClass(String tableName)
{
	String className=DBObject.class.toString();
	Iterator it=map.keySet().iterator();
	while(it.hasNext())
	{
		String cls=(String)it.next();
		DBTable table=(DBTable)map.get(cls);
		if(table.getName().equals(tableName))
		{
			className=cls;
			break;
		}
	}	
	//System.out.println(className);
	return className;
}

}