When you have the library added to your project, you can safely inject the play.api.cache.redis.CacheApi trait for the synchronous cache. If you want the asynchronous implementation, then inject play.api.cache.redis.CacheAsyncApi.
Besides various common operations over the cache, the API supports working with the collections: List, Set, and Map. First, create a typed worker to use the collection under the give key. For example: cache.list[ String ]( "my-list" ) Then you can fully operate the collection. Please be aware of the complexity of the operations and optimize your code. Although the API is simple and seems efficient, each of your calls is transmitted to Redis.
Regardless of current API, all operations throw an exception when fail. Consequently,
successful invocations do not throw an exception. The only difference is in checking for errors.
While synchronous APIs really throw an exception, asynchronous API returns a Future
wrapping both the success and the exception, i.e., use onFailure or onComplete to
check for errors.
import scala.concurrent.Future
import scala.concurrent.duration._
import play.api.cache.redis.CacheApi
class MyController @Inject() ( cache: CacheApi ) {
cache.set( "key", "value" )
// returns Option[ T ] where T stands for String in this example
cache.get[ String ]( "key" )
cache.remove( "key" )
cache.set( "object", MyCaseClass() )
// returns Option[ T ] where T stands for MyCaseClass
cache.get[ MyCaseClass ]( "object" )
// returns Unit
cache.set( "key", 1.23 )
// returns Option[ Double ]
cache.get[ Double ]( "key" )
// returns Option[ MyCaseClass ]
cache.get[ MyCaseClass ]( "object" )
// set multiple values at once
cache.setAll( "key" -> 1.23, "key2" -> 5, "key3" -> 6 )
// set only when all keys are unused
cache.setAllIfNotExist( "key" -> 1.23, "key2" -> 5, "key3" -> 6 )
// get multiple keys at once, returns a list of options
cache.getAll[ Double ]( "key", "key2", "key3", "key6" )
// returns T where T is Double. If the value is not in the cache
// the computed result is saved
cache.getOrElse( "key" )( 1.24 )
// same as getOrElse but works for Futures. It returns Future[ T ]
cache.getOrFuture( "key" )( Future.successful( 1.24 ) )
// returns Unit and removes a key/keys from the storage
cache.remove( "key" )
cache.remove( "key1", "key2" )
cache.remove( "key1", "key2", "key3" )
// remove all expects a sequence of keys, it performs same be behavior
// as remove methods, they are just syntax sugar
cache.removeAll( "key1", "key2", "key3" )
// removes all keys in the redis database! Beware using it
cache.invalidate()
// refreshes expiration of the key if present
cache.expire( "key", 1.second )
// stores the value for infinite time if the key is not used
// returns true when store performed successfully
// returns false when some value was already defined
cache.setIfNotExists( "key", 1.23 )
// stores the value for limited time if the key is not used
// this is not atomic operation, redis does not provide direct support
cache.setIfNotExists( "key", 1.23, 5.seconds )
// returns true if the key is in the storage, false otherwise
cache.exists( "key" )
// returns all keys matching given pattern. Beware, complexity is O(n),
// where n is the size of the database. It executes KEYS command.
cache.matching( "page/1/*" )
// removes all keys matching given pattern. Beware, complexity is O(n),
// where n is the size of the database. It internally uses method matching.
// It executes KEYS and DEL commands in a transaction.
cache.removeMatching( "page/1/*" )
// importing `play.api.cache.redis._` enables us
// using both `java.util.Date` and `org.joda.time.DateTime` as expiration
// dates instead of duration. These implicits are useful when
// we know the data regularly changes, e.g., at midnight, at 3 AM, etc.
// We do not have compute the duration ourselves, the library
// can do it for us
import play.api.cache.redis._
cache.set( "key", "value", DateTime.parse( "2015-12-01T00:00" ).asExpiration )
// atomically increments stored value by one
// initializes with 0 if not exists
cache.increment( "integer" ) // returns 1
cache.increment( "integer" ) // returns 2
cache.increment( "integer", 5 ) // returns 7
// atomically decrements stored value by one
// initializes with 0 if not exists
cache.decrement( "integer" ) // returns -1
cache.decrement( "integer" ) // returns -2
cache.decrement( "integer", 5 ) // returns -7
}import scala.concurrent.Future
import scala.concurrent.duration._
import play.api.cache.redis.CacheApi
class MyController @Inject() ( cache: CacheApi ) {
// enables List operations
// Scala wrapper over the list at this key
cache.list[ String ]( "my-list" )
// get the whole list
cache.list[ String ]( "my-list" ).toList
// prepend values, beware, values are prepended in the reversed order!
// result List( "EFG", "ABC" )
cache.list[ String ]( "my-list" ).prepend( "ABC" ).prepend( "EFG" )
"EFG" +: "ABC" +: cache.list[ String ]( "my-list" )
List( "ABC", "EFG" ) ++: cache.list[ String ]( "my-list" )
// append values to the list
// result List( "ABC", "EFG" )
cache.list[ String ]( "my-list" ).append( "ABC" ).append( "EFG" )
cache.list[ String ]( "my-list" ) :+ "ABC" :+ "EFG"
cache.list[ String ]( "my-list" ) :++ List( "ABC", "EFG" )
// getting a value
cache.list[ String ]( "my-list" ).apply( index = 1 ) // get or an exception
cache.list[ String ]( "my-list" ).get( index = 1 ) // Some or None
cache.list[ String ]( "my-list" ).head // get or an exception
cache.list[ String ]( "my-list" ).headOption // Some or None
cache.list[ String ]( "my-list" ).headPop // Some or None and REMOVE the head
cache.list[ String ]( "my-list" ).last // get or an exception
cache.list[ String ]( "my-list" ).lastOption // Some or None
// size of the list
cache.list[ String ]( "my-list" ).size
// overwrite the value at index
cache.list[ String ]( "my-list" ).set( position = 1, element = "HIJ" )
// remove the value
cache.list[ String ]( "my-list" ).remove( "ABC", count = 2 ) // remove by value
cache.list[ String ]( "my-list" ).removeAt( position = 1 ) // remove by index
// returns an API to reading but not modifying the list
cache.list[ String ]( "my-list" ).view
// returns an API to modify the underlying list
cache.list[ String ]( "my-list" ).modify
}import scala.concurrent.Future
import scala.concurrent.duration._
import play.api.cache.redis.CacheApi
class MyController @Inject() ( cache: CacheApi ) {
// enables Set operations
// Scala wrapper over the set at this key
cache.set[ String ]( "my-set" )
// get the whole set
cache.set[ String ]( "my-set" ).toSet
// add values into the set
cache.set[ String ]( "my-set" ).add( "ABC", "EDF" )
// test existence in the set
cache.set[ String ]( "my-set" ).contains( "ABC" )
// size of the set
cache.set[ String ]( "my-set" ).size
cache.set[ String ]( "my-set" ).isEmpty
cache.set[ String ]( "my-set" ).nonEmpty
// remove the value
cache.set[ String ]( "my-set" ).remove( "ABC" )
}import scala.concurrent.Future
import scala.concurrent.duration._
import play.api.cache.redis.CacheApi
class MyController @Inject() ( cache: CacheApi ) {
// enables Set operations
// Scala wrapper over the map at this key
cache.map[ Int ]( "my-map" )
// get the whole map
cache.map[ Int ]( "my-map" ).toMap
cache.map[ Int ]( "my-map" ).keySet
cache.map[ Int ]( "my-map" ).values
// test existence in the map
cache.map[ Int ]( "my-map" ).contains( "ABC" )
// get single value
cache.map[ Int ]( "my-map" ).get( "ABC" )
// add values into the map
cache.map[ Int ]( "my-map" ).add( "ABC", 5 )
// size of the map
cache.map[ Int ]( "my-map" ).size
cache.map[ Int ]( "my-map" ).isEmpty
cache.map[ Int ]( "my-map" ).nonEmpty
// remove the value
cache.map[ Int ]( "my-map" ).remove( "ABC" )
}