qr code scaner java app Domain models and metadata in Java

Maker QR Code JIS X 0510 in Java Domain models and metadata

Domain models and metadata
QR Code ISO/IEC18004 Encoder In Java
Using Barcode printer for Java Control to generate, create QR Code image in Java applications.
www.OnBarcode.com
QR Code JIS X 0510 Scanner In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
www.OnBarcode.com
Long storedItemId = (Long) item1.get("id"); Session session = getSessionFactory().openSession(); session.beginTransaction(); Map loadedItemMap = (Map) session.load("ItemEntity", storedItemId); loadedItemMap.put("initialPrice", new BigDecimal(100)); session.getTransaction().commit(); session.close();
PDF 417 Creation In Java
Using Barcode generator for Java Control to generate, create PDF417 image in Java applications.
www.OnBarcode.com
Make Barcode In Java
Using Barcode creation for Java Control to generate, create Barcode image in Java applications.
www.OnBarcode.com
All Session methods that have class parameters such as load() also come in an overloaded variation that accepts entity names. After loading an item map, you set a new price and make the modification persistent by committing the transaction, which, by default, triggers dirty checking and flushing of the Session. You can also refer to entity names in HQL queries:
PDF-417 2d Barcode Maker In Java
Using Barcode drawer for Java Control to generate, create PDF417 image in Java applications.
www.OnBarcode.com
Drawing 2D In Java
Using Barcode maker for Java Control to generate, create 2D Barcode image in Java applications.
www.OnBarcode.com
List queriedItemMaps = session.createQuery("from ItemEntity where initialPrice >= :p") .setParameter("p", new BigDecimal(100)) .list();
GS1 DataBar Truncated Encoder In Java
Using Barcode generation for Java Control to generate, create GS1 DataBar image in Java applications.
www.OnBarcode.com
Drawing UPCE In Java
Using Barcode printer for Java Control to generate, create GTIN - 12 image in Java applications.
www.OnBarcode.com
This query returns a collection of ItemEntity maps. They are in persistent state. Let s take this one step further and mix a POJO model with dynamic maps. There are two reasons why you would want to mix a static implementation of your domain model with a dynamic map representation:
QR Code JIS X 0510 Scanner In C#
Using Barcode reader for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Scan Quick Response Code In None
Using Barcode scanner for Software Control to read, scan read, scan image in Software applications.
www.OnBarcode.com
You want to work with a static model based on POJO classes by default, but sometimes you want to represent data easily as maps of maps. This can be particularly useful in reporting, or whenever you have to implement a generic user interface that can represent various entities dynamically. You want to map a single POJO class of your model to several tables and then select the table at runtime by specifying a logical entity name.
PDF-417 2d Barcode Scanner In Visual C#.NET
Using Barcode scanner for .NET framework Control to read, scan read, scan image in .NET applications.
www.OnBarcode.com
Generate Data Matrix 2d Barcode In Objective-C
Using Barcode maker for iPhone Control to generate, create DataMatrix image in iPhone applications.
www.OnBarcode.com
You may find other use cases for mixed entity modes, but they re so rare that we want to focus on the most obvious. First, therefore, you ll mix a static POJO model and enable dynamic map representation for some of the entities, some of the time. Mixing dynamic and static entity modes To enable a mixed model representation, edit your XML mapping metadata and declare a POJO class name and a logical entity name:
Make Barcode In VS .NET
Using Barcode generator for .NET framework Control to generate, create Barcode image in .NET applications.
www.OnBarcode.com
QR-Code Generator In Objective-C
Using Barcode maker for iPhone Control to generate, create Quick Response Code image in iPhone applications.
www.OnBarcode.com
<hibernate-mapping> <class name="model.ItemPojo" entity-name="ItemEntity"
UPCA Reader In VB.NET
Using Barcode reader for .NET Control to read, scan read, scan image in Visual Studio .NET applications.
www.OnBarcode.com
Encoding QR Code ISO/IEC18004 In Visual Studio .NET
Using Barcode generator for ASP.NET Control to generate, create QR-Code image in ASP.NET applications.
www.OnBarcode.com
Alternative entity representation
Barcode Maker In None
Using Barcode creation for Software Control to generate, create Barcode image in Software applications.
www.OnBarcode.com
UPCA Decoder In Visual Studio .NET
Using Barcode scanner for .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
table="ITEM_ENTITY"> ... <many-to-one name="seller" entity-name="UserEntity" column="USER_ID"/> </class> <class name="model.UserPojo" entity-name="UserEntity" table="USER_ENTITY"> ... <bag name="itemsForSale" inverse="true" cascade="all"> <key column="USER_ID"/> <one-to-many entity-name="ItemEntity"/> </bag> </class> </hibernate-mapping>
PDF 417 Reader In Visual Basic .NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in .NET framework applications.
www.OnBarcode.com
EAN 13 Printer In None
Using Barcode maker for Font Control to generate, create GS1 - 13 image in Font applications.
www.OnBarcode.com
Obviously, you also need the two classes, model.ItemPojo and model.UserPojo, that implement the properties of these entities. You still base the many-to-one and one-to-many associations between the two entities on logical names. Hibernate will primarily use the logical names from now on. For example, the following code does not work:
UserPojo user = new UserPojo(); ... ItemPojo item1 = new ItemPojo(); ... ItemPojo item2 = new ItemPojo(); ... Collection itemsForSale = new ArrayList(); ... session.save(user);
The preceding example creates a few objects, sets their properties, and links them, and then tries to save the objects through cascading by passing the user instance to save(). Hibernate inspects the type of this object and tries to figure out what entity it is, and because Hibernate now exclusively relies on logical entity names, it can t find a mapping for model.UserPojo. You need to tell Hibernate the logical name when working with a mixed representation mapping:
... session.save("UserEntity", user);
Once you change this line, the previous code example works. Next, consider loading, and what is returned by queries. By default, a particular SessionFactory
Domain models and metadata
is in POJO entity mode, so the following operations return instances of model.ItemPojo:
Long storedItemId = item1.getId(); ItemPojo loadedItemPojo = (ItemPojo) session.load("ItemEntity", storedItemId); List queriedItemPojos = session.createQuery("from ItemEntity where initialPrice >= :p") .setParameter("p", new BigDecimal(100)) .list();
You can switch to a dynamic map representation either globally or temporarily, but a global switch of the entity mode has serious consequences. To switch globally, add the following to your Hibernate configuration; e.g., in hibernate.cfg.xml:
<property name="default_entity_mode">dynamic-map</property>
All Session operations now either expect or return dynamically typed maps! The previous code examples that stored, loaded, and queried POJO instances no longer work; you need to store and load maps. It s more likely that you want to switch to another entity mode temporarily, so let s assume that you leave the SessionFactory in the default POJO mode. To switch to dynamic maps in a particular Session, you can open up a new temporary Session on top of the existing one. The following code uses such a temporary Session to store a new auction item for an existing seller:
Session dynamicSession = session.getSession(EntityMode.MAP); Map seller = (Map) dynamicSession.load("UserEntity", user.getId() ); Map newItemMap = new HashMap(); newItemMap.put("description", "An item for auction"); newItemMap.put("initialPrice", new BigDecimal(99)); newItemMap.put("seller", seller); dynamicSession.save("ItemEntity", newItemMap); Long storedItemId = (Long) newItemMap.get("id"); Map loadedItemMap = (Map) dynamicSession.load("ItemEntity", storedItemId); List queriedItemMaps = dynamicSession .createQuery("from ItemEntity where initialPrice >= :p") .setParameter("p", new BigDecimal(100)) .list();
The temporary dynamicSession that is opened with getSession() doesn t need to be flushed or closed; it inherits the context of the original Session. You use it
Copyright © OnBarcode.com . All rights reserved.