2aa9e78ddd
* Made minor changes in some patterns such as removed throws clause where not needed, changed incorrect order of arguments in assertEquals * Minor refactorings and code style changes. 1) Removed several use of raw types 2) Removed unnecessary throws clauses 3) Used lambda expressions wherever applicable 4) Used apt assertion methods for readability 5) Use of try with resources wherever applicable 6) Corrected incorrect order of assertXXX arguments * Removed unused import from Promise * Addressed review comments * Addressed checkstyle issue
layout, title, folder, permalink, categories, tags
| layout | title | folder | permalink | categories | tags | |||
|---|---|---|---|---|---|---|---|---|
| pattern | Repository | repository | /patterns/repository/ | Persistence Tier |
|
Intent
Repository layer is added between the domain and data mapping layers to isolate domain objects from details of the database access code and to minimize scattering and duplication of query code. The Repository pattern is especially useful in systems where number of domain classes is large or heavy querying is utilized.
Applicability
Use the Repository pattern when
- the number of domain objects is large
- you want to avoid duplication of query code
- you want to keep the database querying code in single place
- you have multiple data sources