前言

通過redis的java客戶端Jedis遠端連線redis伺服器報錯，錯誤資訊如下：

redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
    at redis.clients.util.Pool.getResource(Pool.java:40)
    at com.firstelite.util.RedisClient.<init>(RedisClient.java:27)
    at com.firstelite.util
 
.Test.main(Test.java:7)
Caused by: redis.clients.jedis.exceptions.JedisConnectionException: java.net.SocketTimeoutException: connect timed out
    at redis.clients.jedis.Connection.connect(Connection.java:137)
    at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:65)
    at redis.clients
 
.jedis.BinaryJedis.connect(BinaryJedis.java:1706)
    at redis.clients.jedis.JedisFactory.makeObject(JedisFactory.java:28)
    at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:1188)
    at redis.clients.util.Pool.getResource(Pool.java:38)
    ... 2 more
Caused by: java.net
 
.SocketTimeoutException: connect timed out
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:75)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:337)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:198)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:180)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:157)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:391)
    at java.net.Socket.connect(Socket.java:579)
    at redis.clients.jedis.Connection.connect(Connection.java:132)
    ... 7 more

很明顯連線超時，經過錯誤排查發現是安裝Redis的CentOS的防火牆沒有關閉，所以關閉防火牆即可。

Close Firewall

在CentOS 7中預設使用firewall做為防火牆，下面是啟動&關閉防火牆的命令：

// 啟動firewall
systemctl start firewalld.service
// 關閉firewall
systemctl stop firewalld.service

我們輸入第二個關閉命令即可，再次執行Java程式即可正常遠端呼叫Redis。

總結

簡單記錄一下解決方案，僅供參考，The End。