[Reprint] Java client Jedis using Redis

Reprinted from http://aofengblog.blog.163.com/blog/static/631702120147298317919/

In real-world project development, various languages are using Redis's client libraries to interact with Redis. For the Java language, Redis officially recommends Jedis.

Jedis provides a variety of operating methods: single-connection mode, stand-alone connection pool mode, multi-machine distributed + connection pool mode.

Prepare

jedis-2.5.2
Commons-pool2-2.2.jar

Using a single connection

This method is recommended only for the development environment to be used as a tuning trial.

// 创建连接
String host = "192.168.56.102";int port = 6379;Jedis client = new Jedis(host, port);
// 执行set指令String result = client.set("key-string", "Hello, Redis!");System.out.println( String.format("set指令执行结果:%s", result) );
// 执行get指令String value = client.get("key-string");System.out.println( String.format("get指令执行结果:%s", value) );

Run the above code, console output:

Set command execution result:OK
Get Command execution result:Hello, Redis!

Using connection pooling

This works for scenarios that use only a single Redis instance.

// 生成连接池配置信息JedisPoolConfig config = new JedisPoolConfig();config.setMaxIdle(10);config.setMaxTotal(30);config.setMaxWaitMillis(3*1000);// 在应用初始化的时候生成连接池JedisPool pool = new JedisPool(config, "192.168.56.102", 6379);// 在业务操作时，从连接池获取连接Jedis client = pool.getResource();try {    // 执行指令    String result = client.set("key-string", "Hello, Redis!");    System.out.println( String.format("set指令执行结果:%s", result) );    String value = client.get("key-string");    System.out.println( String.format("get指令执行结果:%s", value) );} catch (Exception e) {    // TODO: handle exception} finally {    // 业务操作完成，将连接返回给连接池    if (null != client) {        pool.returnResource(client);    }} // end of try block// 应用关闭时，释放连接池资源pool.destroy();

Run the above code, console output:

Set command execution result:OK
Get Command execution result:Hello, Redis!

Using connection pooling + distributed

In larger systems, there are often multiple Redis instances for load balancing. It also implements a master-slave backup that, when the primary instance fails, switches to service from the instance.
Similar to the memcached client, Jedis also provides a way for client-side distributed operations, using a consistent hashing algorithm.

// 生成多机连接信息列表List<JedisShardInfo> shards = new ArrayList<JedisShardInfo>();shards.add( new JedisShardInfo("127.0.0.1", 6379) );shards.add( new JedisShardInfo("192.168.56.102", 6379) );// 生成连接池配置信息JedisPoolConfig config = new JedisPoolConfig();config.setMaxIdle(10);config.setMaxTotal(30);config.setMaxWaitMillis(3*1000);// 在应用初始化的时候生成连接池ShardedJedisPool pool = new ShardedJedisPool(config, shards);// 在业务操作时，从连接池获取连接ShardedJedis client = pool.getResource();try {    // 执行指令    String result = client.set("key-string", "Hello, Redis!");    System.out.println( String.format("set指令执行结果:%s", result) );    String value = client.get("key-string");    System.out.println( String.format("get指令执行结果:%s", value) );} catch (Exception e) {    // TODO: handle exception} finally {    // 业务操作完成，将连接返回给连接池    if (null != client) {        pool.returnResource(client);    }} // end of try block// 应用关闭时，释放连接池资源pool.destroy();

Run the above code, console output:

Set command execution result:OK
Get Command execution result:Hello, Redis!

[Reprint] Java client Jedis using Redis