Skip to main content

Hibernate Meta Model

The meta model is the model used by Hibernate core to perform its object relational mapping. The model includes information about tables, columns, classes, properties, components, values, collections etc. The API is in org.hibernate.mapping and its main entry point is the Configuration class, the same class that is used to build a session factory.


The model represented by the Configuration class can be build in many ways. The following list the currently supported ones in Hibernate Tools.
  • A Core configuration uses Hibernate Core and supports reading hbm.xml files, requires a hibernate.cfg.xml. Named core in Eclipse and <configuration> in ant.
  • A Annotation configuration uses Hibernate Annotations and supports hbm.xml and annotated classes, requires a hibernate.cfg.xml. Named annotations in Eclipse and <annotationconfiguration> in ant.
  • A JPA configuration uses a Hibernate EntityManager and supports hbm.xml and annotated classes requires that the project has a META-INF/persistence.xml in its classpath. Named JPA in Eclipse and <jpaconfiguration> in ant.
  • A JDBC configuration uses Hibernate Tools reverse engineering and reads its mappings via JDBC metadata + additional reverse engineering files (reveng.xml). Automatically used in Eclipse when doing reverse engineering from JDBC and named <jdbcconfiguration> in ant.In most projects you will normally use only one of the Core, Annotation or JPA configuration and possibly the JDBC configuration if you are using the reverse engineering facilities of Hibernate Tools. The important thing to note is that no matter which Hibnerate Configuration type you are using Hibernate Tools supports them.


The code generation is done based on the Configuration model no matter which type of configuration have been used to create the meta model, and thus the code generation is independent on the source of the meta model and represented via Exporters.
Labels:

Comments

Post a Comment

Popular posts from this blog

Advantages & Disadvantages of Synchronous / Asynchronous Communications?

  Asynchronous Communication Advantages: Requests need not be targeted to specific server. Service need not be available when request is made. No blocking, so resources could be freed.  Could use connectionless protocol Disadvantages: Response times are unpredictable. Error handling usually more complex.  Usually requires connection-oriented protocol.  Harder to design apps Synchronous Communication Advantages: Easy to program Outcome is known immediately  Error recovery easier (usually)  Better real-time response (usually) Disadvantages: Service must be up and ready. Requestor blocks, held resources are “tied up”.  Usually requires connection-oriented protocol
Post a Comment
Continue Reading >>>>

WebSphere MQ Interview Questions

What is MQ and what does it do? Ans. MQ stands for MESSAGE QUEUEING. WebSphere MQ allows application programs to use message queuing to participate in message-driven processing. Application programs can communicate across different platforms by using the appropriate message queuing software products. What is Message driven process? Ans . When messages arrive on a queue, they can automatically start an application using triggering. If necessary, the applications can be stopped when the message (or messages) have been processed. What are advantages of the MQ? Ans. 1. Integration. 2. Asynchrony 3. Assured Delivery 4. Scalability. How does it support the Integration? Ans. Because the MQ is independent of the Operating System you use i.e. it may be Windows, Solaris,AIX.It is independent of the protocol (i.e. TCP/IP, LU6.2, SNA, NetBIOS, UDP).It is not required that both the sender and receiver should be running on the same platform What is Asynchrony? Ans. With messag
11 comments
Continue Reading >>>>

XML Binding with JAXB 2.0 - Tutorial

Java Architecture for XML Binding (JAXB) is an API/framework that binds XML schema to Java representations. Java objects may then subsequently be used to marshal or unmarshal XML documents. Marshalling an XML document means creating an XML document from Java objects. Unmarshalling means creating creating a Java representation of an XML document (or, in effect, the reverse of marshaling). You retrieve the element and attribute values of the XML document from the Java representation. The JAXB 2.0 specification is implemented in JWSDP 2.0. JAXB 2.0 has some new features, which facilitate the marshalling and unmarshalling of an XML document. JAXB 2.0 also allows you to map a Java object to an XML document or an XML Schema. Some of the new features in JAXB 2.0 include: Smaller runtime libraries are required for JAXB 2.0, which require lesser runtime memory. Significantly, fewer Java classes are generated from a schema, compared to JAXB 1.0. For each top-level complexType, 2.0 generates a v
Post a Comment
Continue Reading >>>>