Cayenne，开源 ORM 盛宴中的另道佳肴，第 1 部分: 初尝小辣椒 - Apache Cayenne 基本功能

      import org.apache.cayenne.access.DataContext;   ...   DataContext context = DataContext.createDataContext();       

      import org.apache.cayenne.query.SelectQuery;   ...   // this is a valid Cayenne query that would allow to fetch   // all records from the ClientTB table as ClientTB objects   SelectQuery query = new SelectQuery(ClientTB.class);     // create a qualifier with one parameter: "clientID"   Expression qual = Expression.fromString("clientID = $clientID);     // build a query prototype of a query - simply another select query   SelectQuery proto = new SelectQuery(ClientTB.class, qual);     Context.performQuery(proto);       

      Map param = new HashMap();   param.put("manuName","Nokia Beijing");   // 执行“getCommodities” Query 并不刷新 Cache List   context.performQuery(“getCommodities”, param, false);       

      List <ClientTB>  clients = context.performQuery(“allClients”,true);   // 修改 DataObject 的属性  ClientTB clientTB = clients.get(0);   clientTB.setClientMail(“cayennedemo@hotmail.com”);   // 提交修改  context.commitChanges();      

      ClientDao clientDao = (ClientDao)DaoManager.getInstance().getDao(ClientDao.class);   CommodityDao comDao = (CommodityDao) DaoManager.getInstance().getDao(CommodityDao.class);   CayenneStoreDao csd = (CayenneStoreDao)DaoManager.getInstance()           .getDao(CayenneStoreDao.class);   List<ClientTB> clients = clientDao.getClients();   for (ClientTB c : clients){       csd.getDataContext().deleteObject(c);   }   SelectQuery queryCom = new SelectQuery(CommodityTB.class);   List<CommodityTB> coms  = csd.getDataContext().performQuery(queryCom);   for (CommodityTB cd : coms){       csd.getDataContext().deleteObject(cd);   }   csd.commitChanges();       

      QueryChain qc = new QueryChain();   BufferedReader in = new BufferedReader(new       InputStreamReaderDBDataHelper.class.getResourceAsStream("/loadData.sql")));   String line ;   try {   while ((line = in.readLine())!=null){       if (line.endsWith(";")){           line = line.substring(0,line.length()-1);       }       qc.addQuery(new SQLTemplate(getDataDomain().getMap("cayenne-storeMap"), line));   }   } catch (IOException e) {       // TODO Auto-generated catch block       e.printStackTrace();   }   CayenneStoreDao csd  = (CayenneStoreDao)DaoManager.getInstance()           .getDao(CayenneStoreDao.class);   csd.getDataContext().performNonSelectingQuery(qc);       

      ClientDao clientDao = (ClientDao)DaoManager.getInstance().getDao(ClientDao.class);   List<ClientTB> clients = clientDao.getClients();   for (ClientTB ct: clients){       System.out.println("client : "+ct.getObjectId()+           " "+ct.getClientName()+" "+ct.getClientPWD()+" "+ct.getClientMail());   }   String clientName = "YingChu";   ClientTB ctt = clientDao.getClient(clientName);   System.out.println("client YingChu 's id , pwd, mail "+ctt.getObjectId()+           " "+ctt.getClientPWD()+" "+ctt.getClientMail());   List<OrderTB> orders = ctt.getOrdersOwned();   if (orders.size()==0){       System.out.println("The client "+clientName+" doesn't sign any order");   }else{       for (OrderTB order: orders){           List<OrderCommodityTB> orderedComs = order.getCommoditiesContained();           StringBuffer sb = new StringBuffer();           for (OrderCommodityTB com: orderedComs){               sb.append(com.getCommoditiesBought().getComName());               sb.append(" , ");           }           if (sb.length()>0) sb.delete(sb.length()-3, sb.length());           System.out.println("The client "+clientName+              " has ordered the following commodities : "+               sb.toString()+" on "+order.getOrderDate().toString());       }   }       

      //Assume current client is YingChu   ClientDao clientDao = (ClientDao)DaoManager.getInstance().getDao(ClientDao.class);   String clientName = "YingChu";   ClientTB ctt = clientDao.getClient(clientName);      //Assume two commodities are chosen, two is Nokia Phone n95, one is Thinkpad t61p   CommodityDao comDao = (CommodityDao)DaoManager.getInstance().getDao(CommodityDao.class);   CommodityTB nokiacom = comDao.getCommodity("Nokia Phone n95");   CommodityTB thinkPad = comDao.getCommodity("ThinkPad T61p");      //Generate an order record   CayenneStoreDao csd=(CayenneStoreDao)DaoManager.getInstance()       .getDao(CayenneStoreDao.class);   OrderTB order = (OrderTB)csd.getDataContext().createAndRegisterNewObject(OrderTB.class);   Date dd = Calendar.getInstance().getTime();   order.setOrderDate(dd);      //Add the generated order into the buying list of current client   order.setClientBelonged(ctt);      //Generate two records in OrderCommodityTB   OrderCommodityTB OCNokia = (OrderCommodityTB)csd.getDataContext()       .createAndRegisterNewObject(OrderCommodityTB.class);   OCNokia.setComNumber(1);   OrderCommodityTB OCThinkpad = (OrderCommodityTB)csd.getDataContext()       .createAndRegisterNewObject(OrderCommodityTB.class);   OCThinkpad.setComNumber(1);     //Create the relationship between OrderTB and OrderCommodityTB   OCNokia.setBelongedToOrders(order);   OCThinkpad.setBelongedToOrders(order);      //Create the relationship between CommodityTB and OrderCommodityTB   OCNokia.setCommoditiesBought(nokiacom);   OCThinkpad.setCommoditiesBought(thinkPad);      //Update the quantity number in CommodityTB   nokiacom.updateCommodityNumber(1);   thinkPad.updateCommodityNumber(1);      //Commit changes   csd.commitChanges();      //Check the result of purchase   searchClients ();