Best practice #4: Recycle your resources

Invariably, applications waste too much time fetching, creating, or destroying some complex objects or resources. Others may be too expensive for a single application to maintain on a one-to-one basis. Therefore, you should create a limited number of the resource, and share them from a common pool. You can pool many types of resources, from complex objects to connections. J2EE will manage some of these for you. For example, J2EE connection pools can improve performance by an order of magnitude for extreme cases.