JedisUtil

import java.io.File;
import java.io.FileInputStream;
import java.util.Properties;

import org.apache.log4j.Logger;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

public final class JedisUtil {
    private static final Logger LOGGER = Logger.getLogger(JedisUtil.class);
    private static final String FILE_NAME = "redis.properties";
    private static int DEFAULT_DB_INDEX = 0;

    private static JedisPool jedisPool = null;

    private JedisUtil() {
        // private constructor
    }

    private static void initialPool() {
        final Properties configurations = new Properties();
        String filePath;
        String address = "";
        int port = 6379;

        try {
            filePath = JedisUtil.class.getResource("/").getPath() + "/" + FILE_NAME;
            File file = new File(filePath);

            configurations.load(new FileInputStream(file));
            address = configurations.getProperty("address");
            port = Integer.valueOf(configurations.getProperty("port"));

            String strDbIndex = configurations.getProperty("db_index");
            if (strDbIndex != null) {
                DEFAULT_DB_INDEX = Integer.valueOf(strDbIndex);
            }
            LOGGER.info("Redis server info: " + address + ":" + port);

            final JedisPoolConfig config = new JedisPoolConfig();
            String strMaxActive = configurations.getProperty("pool_maxactive");
            if (strMaxActive != null) {
                config.setMaxActive(Integer.valueOf(strMaxActive));
            }
            String strMaxIdle = configurations.getProperty("pool_maxidle");
            if (strMaxIdle != null) {
                config.setMaxIdle(Integer.valueOf(strMaxIdle));
            }
            String strMaxWait = configurations.getProperty("pool_maxwait");
            if (strMaxWait != null) {
                config.setMaxWait(Integer.valueOf(strMaxWait));
            }
            config.setTestOnBorrow(false);

            String strTimeout = configurations.getProperty("pool_connection_timeout");

            int timeout = 2000;
            if (strTimeout != null) {
                timeout = Integer.valueOf(strTimeout);
            }
            jedisPool = new JedisPool(config, address, port, timeout);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {

        }

    }

    public synchronized static Jedis getJedisInstance() {
        if (jedisPool == null) {
            initialPool();
        }
        try {
            if (jedisPool != null) {
                Jedis resource = jedisPool.getResource();
                resource.select(DEFAULT_DB_INDEX);
                return resource;
            } else {
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public synchronized static Jedis getJedisInstance(final int dbIndex) {
        if (jedisPool == null) {
            initialPool();
        }
        try {
            if (jedisPool != null) {
                Jedis resource = jedisPool.getResource();
                resource.select(dbIndex);
                return resource;
            } else {
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    public static void returnResource(final Jedis jedis) {
        if (jedis != null) {
            jedisPool.returnResource(jedis);
        }
    }

}