Shulou(Shulou.com)06/02 Report--

This article focuses on "how to configure Hibernate", interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn how to configure Hibernate.

When we have a persistent class and its mapping file, it's time to configure Hibernate.

Before that, we need a database. HSQL DB is a Java-based SQL database management system (DBMS) that can be downloaded from the HSQL DB website. In fact, all you have to do is download the hsqldb.jar file in the package and put it in the lib/ directory of the development folder.

Create a data directory under the root of the development-this is where HSQL DB stores the data files. Run java-classpath.. / lib/hsqldb.jar org.hsqldb.Server in the data directory at this point to start the database. You can see its startup and binding to the TCP/IP socket in log, which is where our application will connect later. If you want to run a new database in this example, press CTRL + C in the window to close the HSQL database, delete all files in the data/ directory, and then restart the HSQL database.

Hibernate is the layer in your application that connects to the database, so it needs the information to connect. The connection is done through a JDBC connection pool (connection pool) that is also configured by us. Hibernate's release package includes many open source (open source) connection pooling, but in our example we use Hibernate's built-in connection pooling. Note that if you want to use a production (production-quality) third-party connection pooling software, you must copy the required library files to your classpath and use different connection pooling settings.

To save the Hibernate configuration, we can use a simple hibernate.properties file, or a slightly more complex hibernate.cfg.xml, or even completely use the program to Hibernate the configuration. Most users prefer to use XML profiles:

"- / / Hibernate/Hibernate Configuration DTD 3.0//EN"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> org.hsqldb.jdbcDriverproperty > jdbc:hsqldb:hsql://localhostproperty > saproperty > property > 1property > org.hibernate.dialect.HSQLDialectproperty > threadproperty > Org.hibernate.cache.NoCacheProviderproperty > trueproperty > createproperty > session-factory > hibernate-configuration >

Note that this XML configuration uses a different DTD. Here, we configure Hibernate's SessionFactory-, a factory (factory) associated with the global of a particular database. If you want to use multiple databases, use multiple databases, usually in multiple configuration files (to make it easier to start).

The first four property elements contain the necessary JDBC connection information. The property element of the dialect (dialect) indicates the specific SQL variable generated by the Hibernate. As you will soon see, Hibernate's automatic session management of persistence contexts will come in handy. Turning on the hbm2ddl.auto option automatically generates a database schema (schema)-directly added to the database. Of course, this option can also be turned off (by removing the configuration option) or with the help of the Ant task SchemaExport to redirect the database schema to a file. Finally, add a mapping file to the persistent class in the configuration.

Copy this file to the source directory so that it is at the end of the root directory of classpath. The Hibernate configuration automatically looks for a configuration file named hibernate.cfg.xml in the root directory of classpath when it starts.

At this point, I believe you have a deeper understanding of "how to configure Hibernate", might as well come to the actual operation of it! Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.