ADempiere 如何知道 BOM LowLevel

BOM LowLevel::

public class CalculateLowLevel extends SvrProcess
........
int lowlevel = MPPProductBOMLine.getLowLevel(getCtx(), product.get_ID(), get_TrxName());

MPPProductBOMLine.java
public int getLowLevel(int M_Product_ID)
{
int AD_Client_ID = Env.getAD_Client_ID(m_ctx);
tableproduct.clear(); //reset tableproduct cache
DefaultMutableTreeNode ibom = null;
tableproduct.put(M_Product_ID, 0); //insert parent into cache
ibom = iparent(AD_Client_ID, M_Product_ID, 0); //start traversing tree
return ibom.getDepth(); // 第幾層
}


String sql = "SELECT PP_Product_BOMLine_ID "
+ "FROM PP_Product_BOMLine "
+ "WHERE IsActive=? "
+ "AND AD_Client_ID=? "
+ "AND M_Product_ID=?"; // 抓出所有 有用到此料號的 BOM


final String sql =
"SELECT pbom.M_Product_ID, pbom.Value, pbom.PP_Product_BOM_ID"
+ " FROM PP_Product_BOMLine pboml"
+ " INNER JOIN PP_Product_BOM pbom ON (pbom.PP_Product_BOM_ID = pboml.PP_Product_BOM_ID)"
+ " WHERE pbom.IsActive=?"
+ " AND pboml.IsActive=?"
+ " AND pboml.AD_Client_ID=?"
+ " AND pboml.PP_Product_BOMLine_ID=?";