Java連線Redis全過程講解

2022-06-20 14:01:03

Java連線Redis

Jedis Client是Redis官網推薦的一個面向java使用者端，庫檔案實現了對redis各類API進行封裝呼叫.

引入jar包

我建立的是maven專案，所以只用在pom檔案中加入

<!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
		<dependency>
			<groupId>redis.clients</groupId>
			<artifactId>jedis</artifactId>
			<version>3.0.0</version>
		</dependency>

如果不是maven專案，你要確定引入相關依賴

編寫測試類

package cn.jiangdoc;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
/**
 * 
 * @author jiangdoc
 *
 */
public class JedisUtil {
	public static void main(String[] args) {
	//ip地址，埠號
		Jedis jedis = cli_single("192.168.1.103", 6379);
		jedis.set("key", "first Java connect!");
		String value = jedis.get("key");
		System.out.println(value);
		
	}
	/**
	 * 單個連線
	 * 
	 * @param host
	 * @param port
	 * @return
	 */
	public static Jedis cli_single(String host, int port) {
		try {
			return new Jedis(host, port);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}
	/**
	 * 連線池
	 * 
	 * @param host
	 * @param port
	 * @return
	 */
	public static Jedis cli_pool(String host, int port) {
		JedisPoolConfig config = new JedisPoolConfig();
		// 最大連線數
		config.setMaxTotal(10);
		// 最大連線空閒數
		config.setMaxIdle(2);
		JedisPool jedisPool = new JedisPool(config, host, port);
		try{
			
			return jedisPool.getResource();
		}catch(Exception e){
			e.printStackTrace();
			return null;
		}
	}
}

注意：如果出現

報錯：Exception in thread “main” redis.clients.jedis.exceptions.JedisConnectionException:

檢查埠是否開放

解決方法：

1.關閉防火牆：service iptables stop
2.開放埠：

（1.修改組態檔：vi /etc/sysconfig/iptabls 追加：-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 6379-j ACCEPT

（2.包存改變：service iptables save

（3.重啟服務：service iptables restart

檢視redis的組態檔

報錯：DENIED Redis is running in protected mode because protected mode is enabled, no bind address was specified, no authentication password is requested to clients. In this mode connections are only accepted from the loopback interface. If you want to connect from external computers to Redis you may adopt one of the following solutions: 1) Just disable protected mode sending the command ‘CONFIG SET protected-mode no’ from the loopback interface by connecting to Redis from the same host the server is running, however MAKE SURE Redis is not publicly accessible from internet if you do so. Use CONFIG REWRITE to make this change permanent. 2) Alternatively you can just disable the protected mode by editing the Redis configuration file, and setting the protected mode option to ‘no’, and then restarting the server. 3) If you started the server manually just for testing, restart it with the ‘–protected-mode no’ option. 4) Setup a bind address or an authentication password. NOTE: You only need to do one of the above things in order for the server to start accepting connections from the outside.

報錯資訊很長，但是主要是說redis開啟了protected mode，這也是Redis3.2加入的新特性，開啟保護模式的redis只允許本機登入，同樣設定在組態檔redis.conf中

這裡原來是yes代表開啟了保護模式，後面可以填密碼也可以填no代表關閉，我們這裡選擇關閉保護模式，wq儲存退出後再重啟redis-server