Hibernate is one of the most popular Java frameworks out there. In this tutorial we are going through different aspects of the framework and will develop a. Hibernate not only takes care of the mapping from Java classes to database This tutorial is designed for all those Java programmers who would like to. Hibernate Tutorial in PDF - Learn Hibernate in simple and easy steps starting from basic to advanced concepts with examples including Overview, Architecture, .
|Language:||English, Spanish, Dutch|
|Genre:||Health & Fitness|
|Distribution:||Free* [*Register to download]|
experience as software developer and architect in Hibernate / Java Persistence, Jboss A tutorial reader has two addresses, a billing and a delivery address. The order is created and the applications sends the eBook as PDF to the. Hibernate Tutorial. This Section describes about the basics of Hibernate that will help a beginner Please refer the Hibernate PDF guides to get pdf materials . If you are new to Hibernate and Object/Relational Mapping or even Java, please . Save this file to the src/main/java/org/hibernate/tutorial/domain directory.
This object has a Persistent state. It is managed by Hibernate. It is equivalent to the update or insert action under Database. If it is not Re-Attached, it will be removed by the Java Garbage Gollector according to the normal mechanism.
The object will switch to Persistent state. Persistent object will switch to the Removed state. Session; import org. SessionFactory; import org. DataUtils; import org. HibernateUtils; import org. DateFormat; import java. SimpleDateFormat; import java.
Date; import org. In most cases, Hibernate is able to properly determine which dialect to use.
This is particularly useful if your application targets multiple databases. The hbm2ddl. Finally, add the mapping file s for persistent classes to the configuration. ClassLoader lookup.
There are many ways and options to bootstrap a Hibernate SessionFactory. For additional details, see the Native Bootstrapping topical guide. The entity Java class The entity class for this tutorial is org.
Event Notes About the Entity This class uses standard JavaBean naming conventions for property getter and setter methods, as well as private visibility for the fields. Although this is the recommended design, it is not required. The no-argument constructor, which is also a JavaBean convention, is a requirement for all persistent classes.
Hibernate needs to create objects for you, using Java Reflection. The constructor can be private. However, package or public visibility is required for runtime proxy generation and efficient data retrieval without bytecode instrumentation. Hibernate uses the mapping metadata to determine how to load and store objects of the persistent class. The Hibernate mapping file is one choice for providing Hibernate with this metadata.
Example 1. The table attribute names the database table which contains the data for this entity. Example 2.
Tables mapped in Hibernate do not even need to define primary keys. However, it is strongly recommend that all schemas define proper referential integrity.
Therefore id and primary key are used interchangeably throughout Hibernate documentation. It also identifies the id property of the Event class as the property containing the identifier value.
The generator element informs Hibernate about which strategy is used to generated primary key values for this entity.
This example uses a simple incrementing count. Example 3. The date property mapping includes the column attribute, but the title does not.
In the absence of a column attribute, Hibernate uses the property name as the column name. This is appropriate for title, but since date is a reserved keyword in most databases, you need to specify a non-reserved word for the column name. The title mapping also lacks a type attribute. The types declared and used in the mapping files are neither Java data types nor SQL database types. Instead, they are Hibernate mapping types, which are converters which translate between Java and SQL data types.
Hibernate attempts to determine the correct conversion and mapping type autonomously if the type attribute is not specified in the mapping, by using Java reflection to determine the Java type of the declared property and using a default mapping type for that Java type.
In some cases this automatic detection might not chose the default you expect or need, as seen with the date property. Hibernate cannot know if the property, which is of type java. Full date and time information is preserved by mapping the property to the timestamp converter, which identifies the converter class org.
Hibernate determines the mapping type using reflection when the mapping files are processed. This process adds overhead in terms of time and resources. If startup performance is important, consider explicitly defining the type to use.
Example code The org. The examples in these tutorials are presented as JUnit tests, for ease of use. One benefit of this approach is that setUp and tearDown roughly illustrate how a org. SessionFactory is created at the start-up of an application and closed at the end of the application lifecycle.
Example 4. Obtaining the org. StandardServiceRegistry instance which incorporates configuration information into a working set of Services for use by the SessionFactory.
In this tutorial we defined all configuration information in hibernate. Using the StandardServiceRegistry we create the org. MetadataSources which is the start point for telling Hibernate about your domain model. Again, since we defined that in hibernate. Metadata represents the complete, partially validated view of the application domain model which the SessionFactory will be based on. The final step in the bootstrap process is to build the SessionFactory.
The SessionFactory is a thread-safe object that is instantiated once to serve the entire application.
The SessionFactory acts as a factory for org. Session instances, which should be thought of as a corollary to a "unit of work". Example 5. Example 6. Take it further! Reconfigure the examples to connect to your own persistent relational database. Add an association to the Event entity to model a message thread.