Redis code connection and problems encountered

package com.study.util;

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

public  class RedisUtil {

    private static final String host = "192.168.150.129";
    
    private static final int port = 6379;
    
    private static final String password = "1234";
    
    private static JedisPool jedisPool;
    
    
    public static Jedis getJedis() {
        
        JedisPoolConfig config = new JedisPoolConfig(); 
        config.setMaxTotal(20); 
        config.setMaxIdle(5); 
        config.setTestOnBorrow(false); 
        
        jedisPool = new JedisPool(config,host, port,3000,password);
        Jedis jedis = jedisPool.getResource(); 
        String code = jedis.auth(password); // If password authentication is not configured, this sentence is commented out
         // System.out.println("auth code :" + code); 
        jedis.select(1); // Select the second database demo 
        return jedis;
    }
    
    
    
    public static void main(String[] args) {
        Jedis jedis = getJedis();
        jedis.close();
    }
    
}

The problem encountered when redis connects: Caused by: java.net.ConnectException: Connection refused: connect

Exception in thread "main" redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
    at redis.clients.util.Pool.getResource(Pool.java:53)
    at redis.clients.jedis.JedisPool.getResource(JedisPool.java:226)
    at com.study.util.RedisUtil.main(RedisUtil.java:50)
Caused by: redis.clients.jedis.exceptions.JedisConnectionException: java.net.ConnectException: Connection refused: connect
    at redis.clients.jedis.Connection.connect(Connection.java:207)
    at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:93)
    at redis.clients.jedis.BinaryJedis.connect(BinaryJedis.java:1767)
    at redis.clients.jedis.JedisFactory.makeObject(JedisFactory.java:106)
    at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:889)
    at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:433)
    at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:362)
    at redis.clients.util.Pool.getResource(Pool.java:49)
    ... 2 more
Caused by: java.net.ConnectException: Connection refused: connect
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at redis.clients.jedis.Connection.connect(Connection.java:184)

View Code

Solution:

Check whether the default only local access to redis can be changed to all IPs

bind 127.0.0.1 to bind 0.0.0.0 

Modify the redis configuration file redis.conf and change bind to 0.0.0.0 

Problem 2 encountered: Caused by: java.net.SocketTimeoutException: connect timed out

Exception in thread "main" redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
    at redis.clients.util.Pool.getResource(Pool.java:53)
    at redis.clients.jedis.JedisPool.getResource(JedisPool.java:226)
    at com.study.util.RedisUtil.getJedis (RedisUtil.java: 29 )
    at com.study.util.RedisUtil.main(RedisUtil.java:39)
Caused by: redis.clients.jedis.exceptions.JedisConnectionException: java.net.SocketTimeoutException: connect timed out
    at redis.clients.jedis.Connection.connect(Connection.java:207)
    at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:93)
    at redis.clients.jedis.BinaryJedis.connect(BinaryJedis.java:1767)
    at redis.clients.jedis.JedisFactory.makeObject(JedisFactory.java:106)
    at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:889)
    at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:433)
    at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:362)
    at redis.clients.util.Pool.getResource(Pool.java:49)
    ... 3 more
Caused by: java.net.SocketTimeoutException: connect timed out
    at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at redis.clients.jedis.Connection.connect(Connection.java:184)
    ... 10 more

View Code

Solution:

• 1. Turn off the firewall

• systemctl stop firewalld.service

   

• 2. Open a port    6379

• firewall-cmd --zone=public --add-port=6379/tcp --permanent

  --permanent takes effect permanently, it will be invalid after restart without this parameter

• reload

firewall-cmd --reload