Head First Servlets and JSP, 2nd Edition

Service Locator

Use the Service Locator pattern to perform registry lookups so you can simplify all of the other components (such as Business Delegates) that have to do JNDI (or other registry types) lookups.

Service Locator features

• Obtains InitialContext objects.

• Performs registry lookups.

• Handles communication details and exceptions.

• Can improve performance by caching previously obtained references.

• Works with a variety of registries such as: JNDI, RMI, UDDI, and COS naming.

Service Locator principles

• The Service Locator is based on:

  • hiding complexity

  • separation of concerns

• Minimizes the impact on the web tier when remote components change locations or containers.

• Reduces coupling between tiers.