Apache ObJectRelationalBridge (OJB) is an Object/Relational mapping tool that allows transparent persistence for Java

Java (programming language)

Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...

 Objects against relational database

Relational database

A relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...

s.

Apache OJB was released on April 6th, 2005.

Features

• OJB is open source
  Open source
  The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
  
  (open source code).
• Is also lightweight and easy to use, because to implement a persistence layer, one must simply configure two files (see section below)
• Easy to integrate into an existing application because it does not generate code.
• Allows the use of different patterns of persistence: owner (PersistenceBroker API), JDO
  JDO
  JDO may refer to:* Java Data Objects* The Jewish Defense Organization...
  
   and Object Data Management Group (ODMG).

Configuration

At least two files are required to configure OJB:

• OJB.properties
• repository.xml

Allocation

For mapping a 1-1 relationship, for example, you have two tables: person and account. In this case, a person has an account and vice versa.

External links

• Apache ObJectRelationalBridge