8 | JPA Entity Fields, such as Hibernate, using property access may have some performance benefits. This is not the case |
8 | Storing JPA Entity Objects. Storing a large amount of entity objects can also be performed by multiple transactions: em |
8 | FROM clause (JPQL / Criteria API) could also cause performance problems. For example, let's look at the following query execution |
8 | JPA / JDO Class EnhancerObjectDB Enhancer is a post compilation tool that improves performance by modifying the byte code of compiled classes after compilation. Enhancement is mainly for user-defined persistable classes (entity classes, embeddable classes and mapped superclasses), and is usually optional |
8 | Obtaining a JPA Database Connection, update, and delete should only be performed within an active transaction. Given an EntityManager, em |
1 | Step 4: Add a Servlet Class(request, response); } } GuestServlet performs the following operations on every http request |
1 | Step 3: Add a Context Listener ClassThe Guest entity objects will be stored in an ObjectDB database, which will be represented by a JPA's EntityManagerFactory instance with a global application scope. We have to register a ServletContextListener to perform initialization and cleanup operations: The database will be opened (or created |
1 | Step 3: Define an EJB Session BeanOperations on the database will be performed by an instance of a session bean (EJB) class that we will define in this step: Open the [New Session Bean] dialog box by right clicking the guest package node (in the [Projects] window), selecting New > Other... > Java EE (or Enterprise JavaBeans |
1 | Step 3: Define a Spring DAO ComponentOperations on the database will be performed by an instance of a Data Access Object (DAO) that we will define in this step as a Spring MVC component: Open the [New Java Class] dialog box by right clicking the guest package node (in the [Projects] window under Source Packages) and selecting New |
1 | Step 3: Define a Spring DAO ComponentOperations on the database will be performed by an instance of a Data Access Object (DAO) that we will define in this step as a Spring MVC component: Open the [New Java Class] dialog box by right clicking the guest package node (in the [Package Explorer] window) and selecting New > Class |
