cd2a2e7711
* Moves saga to Java 11 * Moves semaphore to Java 11 * Moves servant to Java 11 * Moves serverless to Java 11 * Moves service-layer to Java 11 * Moves service-locator to Java 11 * Moves sharding to Java 11 * Moves singleton to Java 11 * Moves spatial-partition to Java 11 * Moves specification to Java 11 * Moves state to Java 11 * Moves step-builder to Java 11 * Moves strategy to Java 11 * Moves subclass-sandbox to Java 11 * Fixes checkstyle issues
layout, title, folder, permalink, categories, tags
| layout | title | folder | permalink | categories | tags | ||
|---|---|---|---|---|---|---|---|
| pattern | Service Locator | service-locator | /patterns/service-locator/ | Architectural |
|
Intent
Encapsulate the processes involved in obtaining a service with a strong abstraction layer.
Class diagram
Applicability
The service locator pattern is applicable whenever we want to locate/fetch various services using JNDI which, typically, is a redundant and expensive lookup. The service Locator pattern addresses this expensive lookup by making use of caching techniques ie. for the very first time a particular service is requested, the service Locator looks up in JNDI, fetched the relevant service and then finally caches this service object. Now, further lookups of the same service via Service Locator is done in its cache which improves the performance of application to great extent.
Typical Use Case
- When network hits are expensive and time consuming
- Lookups of services are done quite frequently
- Large number of services are being used
Consequences
- Violates Interface Segregation Principle (ISP) by providing pattern consumers with an access to a number of services that they don't potentially need.
- Creates hidden dependencies that can break the clients at runtime.