Package overit.geocall.cache

Interface RedisDB

public interface RedisDB

Connector for communications to and from the redis server

Method Summary

Modifier and Type	Method	Description
void	broadcast(overit.geocall.cluster.redis.Message msg, boolean meToo)	Sends a broadcast message to all listeners who have registered on the current channel.
void	del(String key)	Fast way to delete a single key from redis.
void	del(String pattern, String type)	removes all records whose key matches the pattern passed as input
<T> T	execute(Function<redis.clients.jedis.Jedis,T> function)	Creates a new Jedis connection and pass it as argument to the function parameter that can execute the commands to the redis server.
String	get(String key)	Fast way to get a single string from redis.
boolean	isReady()	Check if the Redis service is available and running
Set<String>	keys(String pattern, String type)	Extracts a set of keys from the redis server.
String	normalizeKey(String key)	Normalize the given key by appending a prefix based on the deployment ID.
void	onMessage(Consumer<overit.geocall.cluster.redis.Message> listener)	Records a listener on receipt of a message from the redis server.
void	onReconnect(Runnable listener)	Records a listener on the reconnection event to the redis server.
void	set(String key, String value)	Fast way to set a new string inside redis.
void	stop()	Close the communication with the redis server.
void	unwatch()	Method used to unsubscribe the previous subscription (if any)
void	watch(String channel)	Method used to subscribe to the reception of notifications from a certain channel.

Method Details

normalizeKey

String normalizeKey(String key)

Normalize the given key by appending a prefix based on the deployment ID. If the deployment ID is not available, the prefix "unknown" will be used. The normalized key will have the format "{prefix}:{key}".

Parameters:

key - the key to be normalized

Returns:

the normalized key

stop

void stop()

Close the communication with the redis server. After the invocation of this method, no mere connections can be extracted.

watch

void watch(String channel)

Method used to subscribe to the reception of notifications from a certain channel. The sequent subscription will have no effect; you have to call the unwatch() method before subscribe again to a new channel

Parameters:

channel - name of the channel to subscribe to

unwatch

void unwatch()

Method used to unsubscribe the previous subscription (if any)

onReconnect

void onReconnect(Runnable listener)

Records a listener on the reconnection event to the redis server. The watch(String) must be called before the registration, otherwise no notification will be received.

Parameters:

listener - instance of the listener that will be called on every reconnection.

onMessage

void onMessage(Consumer<overit.geocall.cluster.redis.Message> listener)

Records a listener on receipt of a message from the redis server. The watch(String) must be called before the registration, otherwise no notification will be received.

Parameters:

listener - instance of the listener that will be called on every message.

execute

<T> T execute(Function<redis.clients.jedis.Jedis,T> function)

Creates a new Jedis connection and pass it as argument to the function parameter that can execute the commands to the redis server. After the function has been called, the connection will be closed.

Type Parameters:

T - the function return type

Parameters:

function - the function that will be called once the connection has been created

Returns:

the function execution result

keys

Set<String> keys(String pattern,
 String type)
          throws RedisDBException

Extracts a set of keys from the redis server. The result set contains only the keys that respect a specific pattern

Parameters:

pattern - see MATCH option in the Redis documentation

type - see TYPE option in the Redis documentation

Returns:

a set of the extracted key of an empty set if there's none that matches with the pattern

Throws:

RedisDBException - in case of any error during the key extraction

del

void del(String pattern,
 String type)
  throws RedisDBException

removes all records whose key matches the pattern passed as input

Parameters:

pattern - see MATCH option in the Redis documentation

type - see TYPE option in the Redis documentation

Throws:

RedisDBException - in case of any error during the removal

broadcast

void broadcast(overit.geocall.cluster.redis.Message msg,
 boolean meToo)
        throws RedisDBException

Sends a broadcast message to all listeners who have registered on the current channel. The watch(String) must be called before use this method.

Parameters:

msg - the message that will be send

meToo - true di the notification must be received by the listeners registered to this connector, false otherwise

Throws:

IllegalStateException - if you have not subscribed to any channel

RedisDBException - in case of any error during the sending

set

void set(String key,
 String value)

Fast way to set a new string inside redis. This method is intended for a simple use case that doesn't require to pipeline commands, or set additional parameters like NX, EX ... . To support complex use cases, use the execute(Function) method.

Parameters:

key - the reference key

value - the value that will be set

get

String get(String key)

Fast way to get a single string from redis. This method is intended for a simple use case that doesn't require to pipeline commands. To support complex use cases, use the execute(Function) method.

Parameters:

key - the reference key

Returns:

the key value or null if the key doesn't exist

del

void del(String key)

Fast way to delete a single key from redis. This method is intended for a simple use case that doesn't require to pipeline commands. To support complex use cases, use the execute(Function) method.

Parameters:

key - the reference key

isReady

boolean isReady()

Check if the Redis service is available and running

Returns:

true if Redis is up and running; false otherwise