What is joo?

Joodbms (joo) is a free and lightweight object-oriented database system for use in Java development.

The goal

The goal of joo was to produce a streamlined database system that provides object storage and access via similar methods to those of the OODBMS (i.e. retrieval via a unique object identifier, use of a single-level storage model etc.). In addition to simplicity it was important to ensure the system is robust and that the database data is easily accessible and portable for any implementation specific actions that a developer may wish to take (such as a database backup function).

Why use joo?

While joo is no replacement for the high profile database systems provided by companies such as Oracle, it is great at what it does; that being:

• Provide developers with a quick and easy programming interface
• Provide a portable database system that doesn’t rely on any background services
• Provide a platform independent database system

In addition to these key features, joo is completely free and open source; meaning you are free to derive any projects based on the source code, or simply utilise it in its original form in your own project. It should be noted that although joo is an open source system you are not permitted to redistribute the source code as your own unless distributed under the same license that we employ (see the GPL and Disclaimer pages for more information regarding your rights and the end-user agreement).

How does joo work?

The databases created by joo follow a two tier structure; clusters being the first point of access, and then the objects being the children. A cluster groups objects together in order to create a more manageable database (similar to tables in relational database systems such as MySQL); for example if you needed to store sprite objects and authentication objects it would be more logical to put them each in their own cluster as they share no semantic relation.

To actually put joo to use one must simply include the required files in their Java project and create a joo object like in the example below:

import Joo.*;
 
public class JooTest {
	public static void main(String[] args) {
		// Create a new Joo object and connect to the database
		Joo test = new Joo();
		System.out.println(test.connect("path to the database"));
 
		// Create and store an object in the cluster named "cluster01"
		String objectToStore = "Hello world!";
		test.storeObject("cluster01", objectToStore);
 
		// Retrieve object 2 from cluster01 and output it to the console
		String retrievedObject = (String)test.getObject("cluster01", 2);
		System.out.println(retrievedObject);
	}
}

For more information on how to use joo see the Online Documentation or refer to the documentation that came packaged with the download.