lettuce - A scalable Java Redis client

Lettuce is a scalable thread-safe Redis client providing both synchronous and asyncronous connections. Multiple threads may share one connection provided they avoid blocking and transactional operations such as BLPOP, and MULTI/EXEC. Multiple connections are efficiently managed by the excellent netty NIO framework.

This version of lettuce has been tested against redis 2.6.12

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Basic Usage

RedisClient client = new RedisClient("localhost") RedisConnection<String, String> connection = client.connect() String value = connection.get("key")

Each redis command is implemented by one or more methods with names identical to the lowercase redis command name. Complex commands with multiple modifiers that change the result type include the CamelCased modifier as part of the command name, e.g. zrangebyscore and zrangebyscoreWithScores.

Redis connections are designed to be long-lived, and if the connection is lost will reconnect until close() is called. Pending commands that have not timed out will be (re)sent after successful reconnection.

All connections inherit a default timeout from their RedisClient and and will throw a RedisException when non-blocking commands fail to return a result before the timeout expires. The timeout defaults to 60 seconds and may be changed in the RedisClient or for each individual connection.

Asynchronous Connections

RedisAsyncConnection<String, String> async = client.connectAsync() Future set = async.set("key", "value") Future get = async.get("key")

async.awaitAll(set, get) == true

set.get() == "OK" get.get() == "value"

Pub/Sub

RedisPubSubConnection<String, String> connection = client.connectPubSub() connection.addListener(new RedisPubSubListener<String, String>() { ... }) connection.subscribe("channel")

Codecs

Lettuce supports pluggable codecs responsible for encoding and decoding keys and values. The default codec supports UTF-8 encoded String keys and values.

Each connection may have its own codec passed to the extended RedisClient.connect methods:

RedisConnection<K, V> connect(RedisCodec<K, V> codec) RedisAsyncConnection<K, V> connectAsync(RedisCodec<K, V> codec) RedisPubSubConnection<K, V> connectPubSub(RedisCodec<K, V> codec)

For pub/sub connections channel names and patterns are treated as keys, messages are treated as values.

Maven Artifacts

Releases of lettuce are available in the maven central repository.