1-minute Introduction

Authors: cv and Jon Tirsen

What is Prevayler?

• Prevayler is a lightweight implementation of a prevalent persistence mechanism.
• It is not a database, but can be used as a replacement for a database in many circumstances.
• Prevayler has no external dependencies, except JDK 1.3.

What does Prevayler do?

• It uses object serialization to store all the modifications to your data in a sequential form.
• When the application is restarted, it reads and executes all those modifications again, thus bringing the data to the same state it was before the restart.
• Optionally, you can take "snapshots" of your whole object graph, so re-executing all the modifications performed since the applications started is not needed.

How do I use Prevayler?

• The Prevayler release is just one JAR file. You just need to add it to your CLASSPATH and you can start working immediately.
• Create your domain model. It should not depend on any external resources specifically not Prevayler itself. It also needs to be serializable.
• Create a Transaction (Command) object for each type of modification to the system. They need to be serializable.
• Create a Prevayler instance and execute all your transactions through it.

For further information, read the 2-minute Tutorial.

Why should I use Prevayler?

• Simpler and faster development time.
• Insanely fast object lookups and manipulation with less code.