Part one and two ( 1 controller: DemoArrayController)

• save() : Insert array of integer to H2.DB and memory. When added to database, the order of elements of an array is ignored. if successfully inserted then will be added to memory
• get() : Return ID of array from memory. if not exists then query database , throws exception if not found in DB
• getPermutation() : Return a random order of an array by ID from memory, if not found then query database, it will throw exception if not found in database
• removeMemory() : Clear memory.
• getFromMemory() : Return ID only from memory

Controller detail

• Calling end point POST http://localhost:5000/store?numbers=2,1,3,4,6,5,7 save an array to database and memory
• Calling end point GET http://localhost:5000/store?numbers=2,1,3,4,6,5,7 returns an ID of the array from memory or database, throws exception if not found.
• Calling end point GET http://localhost:5000/permutation?id=2 returns a random permutation of the array from memory or database, throws exception if not found.
• Calling end point GET `http://localhost:5000/memroy?numbers=2,1,3,4,6,5,7`` returns an ID from memory or database, throws exception if not found.
• Calling end point DELETE http://localhost:5000/clear/memory clears the memory.

Services ( 1 service: DemoService )

Supports controller's request

• save(DemoArrayDTO source): add array to memory and return the object back in DTO format DemoArray
• getId(DemoArrayDTO source): get ID of an array in DTO format DemoArray if not found throws Exception
• getArray(DemoArrayDTO source): get ID and array in DTO format
• getSuffeled(Integer[] numbers): change the order of array's element inside array randomly
• clearCache(): remove all available element inside cache

Manager ( 1 Manger: DemoCacheManager )

Manages In-Memory cache inquiries

• getDemoCache() : return object cache numberMap
• clearAll(): removes all elements of the cache
• getByKey(): returns array by cache key
• add(): add new array to cache
• getCacheKey: create a unique hash code key. order of elements are ignored. same content but 2 different order are identical

Data transfer object DTO DemoArrayDTO and DemoCacheDTO)

• DemoArrayDTO : matching DemoArray entity
• DemoCacheDTO : cache response object when has been cleared.

Repository

DemoArray is an entity model mapping table TBL_DEMO_ARRAY

• id : PK : hash-code
• numbers : CLOB that holds JSON array of numbers

Converter

MapperService converts DTO to entity and vice versa

In-Memory Cache configuration (CacheConfig )

• Includes in-memory spring boot cache

Integration test

• DemoSeverBootTestIT

Unit tests

• DemoApplicationTests
• DemoArrayControllerTest
• DemoServiceTest
• DemoServiceBootTest
• DemoArrayRepositoryTest