在使用 Java 連線 redis 之前，需先：

1. 配置伺服器的防火牆策略。
2. 修改 redis 配置檔案。

配置防火牆策略

開啟 /etc/sysconfig/iptables 檔案：

# vim /etc/sysconfig/iptables

開放 6379 埠（第 11 行）：

# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 6379 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 8080 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT
 

重啟防火牆（第 1 行）：

# service iptables restart
iptables: Setting chains to policy ACCEPT: filter          [  OK  ]
iptables: Flushing firewall rules:                         [  OK  ]
iptables: Unloading modules:                               [  OK  ]
iptables: Applying firewall rules:                         [  OK  ]
 

修改 redis 配置檔案

註釋第 22 行 bind 127.0.0.1，監聽所有來自伺服器網絡卡的連線請求：

# By default,if no "bind" configuration directive is specified,Redis listens
# for connections from all the network interfaces available on the server.
# It is possible to listen to just one or multiple selected interfaces using
# the "bind" configuration directive,followed by one or more IP addresses.
#
# Examples:
#
# bind 192.168.1.100 10.0.0.1
# bind 127.0.0.1 ::1
#
# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
# internet,binding to all the interfaces is dangerous and will expose the
# instance to everybody on the internet. So by default we uncomment the
# following bind directive,that will force Redis to listen only into
# the IPv4 loopback interface address (this means Redis will be able to
# accept connections only from clients running into the same computer it
# is running).
#
# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
# JUST COMMENT THE FOLLOWING LINE.
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# bind 127.0.0.1
 

注意：如果伺服器是暴露在網際網路中，則不可以這樣做。

關閉保護模式（第 18 行）：

# Protected mode is a layer of security protection,in order to avoid that
# Redis instances left open on the internet are accessed and exploited.
#
# When protected mode is on and if:
#
# 1) The server is not binding explicitly to a set of addresses using the
#    "bind" directive.
# 2) No password is configured.
#
# The server only accepts connections from clients connecting from the
# IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1,and from Unix domain
# sockets.
#
# By default protected mode is enabled. You should disable it only if
# you are sure you want clients from other hosts to connect to Redis
# even if no authentication is configured,nor a specific set of interfaces
# are explicitly listed using the "bind" directive.
protected-mode no

設定認證密碼（第 13 行）：

# Require clients to issue AUTH <PASSWORD> before processing any other
# commands.  This might be useful in environments in which you do not trust
# others with access to the host running redis-server.
#
# This should stay commented out for backward compatibility and because most
# people do not need auth (e.g. they run their own servers).
#
# Warning: since Redis is pretty fast an outside user can try up to
# 150k passwords per second against a good box. This means that you should
# use a very strong password otherwise it will be very easy to break.
#
# requirepass foobared
requirepass 123456

Java 連線 redis

Maven 專案，需要引入依賴：

<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
    <version>3.2.0</version>
</dependency>

連通性測試

import redis.clients.jedis.Jedis;

public class ConnectionTest {
    
    public static void main(String[] args) {
        String host = "192.168.51.107";
        int port = 6379;
        String password = "123456";
        
        Jedis jedis = new Jedis(host,port);
        jedis.auth(password);
        
        String ping = jedis.ping();
        
        System.out.println(ping);
        jedis.close();
    }
}

如果控制檯能輸出 PONG，表示連線成功。