Redis学习笔记(三)：Java连接Redis(Jedis)以及示例代码

r囧r小猫 2023-02-17 05:06 21阅读 0赞

> **Redis学习笔记系列**
> 
>  *  [Redis学习笔记(一)：下载与安装-Windows、Linux][Redis_-Windows_Linux]
>  *  [Redis学习笔记(二)：数据类型和通用操作命令][Redis]
>  *  [Redis学习笔记(三)：Java连接Redis(Jedis)以及示例代码][Redis_Java_Redis_Jedis]
>  *  [Redis学习笔记(四)：Redis持久化][Redis_Redis]
>  *  [Redis学习笔记(五)：Redis事务-multi、exec、discard、锁、分布式锁、死锁][Redis_Redis_-multi_exec_discard]
>  *  [Redis学习笔记(六)：删除策略、逐出算法][Redis 1]
>  *  [Redis学习笔记(七)：redis高级数据类型及应用场景-Bitmaps、HyperLogLog、GEO][Redis_redis_-Bitmaps_HyperLogLog_GEO]
>  *  [Redis学习笔记(八)：redis主从复制-建立连接、数据同步、命令传播、复制缓冲区、复制偏移量、心跳机制][Redis_redis_-]
>  *  [Redis学习笔记(九)：哨兵模式-监控、通知、故障转移][Redis_-]
>  *  [Redis学习笔记(十)：Redis集群-结构设计、集群搭建、集群操作、主从下线、主从切换][Redis_Redis_-]
>  *  [Redis学习笔记(十一)：企业级解决方案-缓存预热、缓存雪崩、缓存击穿、缓存穿透、性能指标监控][Redis_- 1]

# Jedis简介 #

*  Jedis是java连接redis服务的途径，但并不是java连接redis的唯一途径，Java连接redis服务有以下途径:

> Jedis  
> SpringData Redis  
> Lettuce

# HelloWorld #

1.  jar包导入  
    下载地址：[https://mvnrepository.com/artifact/redis.clients/jedis][https_mvnrepository.com_artifact_redis.clients_jedis]

*  Maven

<dependency>
    	<groupId>redis.clients</groupId>
    	<artifactId>jedis</artifactId>
    	<version>3.3.0</version>
    </dependency>

*  Gradle

compile group: 'redis.clients', name: 'jedis', version: '3.3.0'

2.Jedis常规操作：编写代码

*  连接redis

@Test
        public void jedisTest(){ 
            //1.连接redis
            Jedis jedis = new Jedis("127.0.0.1",6379);
            //2.操作redis
            String setResult = jedis.set("sam", "123");
            System.out.println(setResult);
            String value = jedis.get("sam");
            System.out.println(value);
            //3.关闭redis
            jedis.close();
        }

结果输出：

OK
    123

*  redis操作List

@Test
        public void testList(){ 
            //1.连接redis
            Jedis jedis = new Jedis("127.0.0.1",6379);
            //2.操作redis
            jedis.lpush("list1","a","b","c");
            jedis.rpush("list1","d");
            List<String> list1 = jedis.lrange("list1", 0, -1);
            list1.forEach(s -> { 
                System.out.println(s);
            });
            System.out.println(jedis.llen("list1"));
            //3.关闭redis
            jedis.close();
        }

结果输出：

c
    b
    a
    d
    4

*  redis操作Hash

@Test
        public void testHash(){ 
            //1.连接redis
            Jedis jedis = new Jedis("127.0.0.1",6379);
            //2.操作redis
            jedis.hset("hash1","a","1");
            Map<String,String> hash = new HashMap<>();
            hash.put("b","2");
            hash.put("c","3");
            jedis.hmset("hash1",hash);
            Map<String, String> hash1 = jedis.hgetAll("hash1");
            hash1.entrySet().forEach(h ->{ 
                System.out.println("key:" + h.getKey() +" value:" + h.getValue());
            });
            System.out.println(jedis.hlen("hash1"));
            //3.关闭redis
            jedis.close();
        }

结果输出：

key:a value:1
    key:b value:2
    key:c value:3
    3

--------------------

# 案例：根据用户级别，控制业务请求次数 #

package com.ysa.redis.demo1;
    
    import com.ysa.redis.demo1.utils.RedisUtils;
    import redis.clients.jedis.Jedis;
    import redis.clients.jedis.exceptions.JedisDataException;
    
    import java.util.spi.CurrencyNameProvider;
    
    public class RedisService { 
    
        public void control(String id, Integer num){ 
            Jedis jedis = RedisUtils.getJedis();
            String user = jedis.get("userId:" + id);
            try { 
                Long count = Long.MAX_VALUE - num + 1;
                if(user == null){ 
                    jedis.setex("userId:" + id, Integer.parseInt(RedisUtils.getResourceVal(RedisUtils.remoteTime)), String.valueOf(count));
                }else{ 
                    count = jedis.incr("userId:" + id);
                }
                service(id,(num - (Long.MAX_VALUE - count)));
            }catch (JedisDataException e){ 
                System.out.println("id:"+id+" 调用业务已经超过限制，请升级会员");
            }finally { 
                jedis.close();
            }
        }
    
        public void service(String id, Long count) { 
            System.out.println("id: "+id+" 业务操作第" + count + "次");
        }
    }
    
    class Customer implements Runnable{ 
        private String id;
        private Integer num;
    
        public Customer(String id, Integer num) { 
            this.id = id;
            this.num = num;
        }
        RedisService rs = new RedisService();
    
        @Override
        public void run() { 
            while(true){ 
                rs.control(id, num);
                try { 
                    Thread.sleep(new Double(500 + Math.random()*500).longValue());
                } catch (InterruptedException e) { 
                    e.printStackTrace();
                }
            }
        }
    }
    
    class Main{ 
        public static void main(String[] args) { 
            Thread t1 = new Thread(new Customer("初级用户",10));
            Thread t2 = new Thread(new Customer("高级用户",15));
            t1.start();
            t2.start();
        }
    }

package com.ysa.redis.demo1.utils;
    
    import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
    import redis.clients.jedis.Jedis;
    import redis.clients.jedis.JedisPool;
    
    import java.util.HashMap;
    import java.util.Map;
    import java.util.ResourceBundle;
    
    public class RedisUtils { 
        public static final String resource_name = "redis";
        public static final String host = "redis.host";
        public static final String port = "redis.port";
        public static final String maxTotal = "redis.maxTotal";
        public static final String maxIdle = "redis.maxIdle";
        public static final String remoteTime = "redis.remoteTime";
        private static Map<String,Object> resource = new HashMap<>();
        static{ 
            ResourceBundle rb = ResourceBundle.getBundle(resource_name);
            resource.put(host,rb.getObject(host));
            resource.put(port,rb.getObject(port));
            resource.put(maxTotal,rb.getObject(maxTotal));
            resource.put(maxIdle,rb.getObject(maxIdle));
            resource.put(remoteTime,rb.getObject(remoteTime));
        }
        public static Jedis getJedis(){ 
            GenericObjectPoolConfig config = new GenericObjectPoolConfig();
            config.setMaxTotal(Integer.parseInt(getResourceVal(maxTotal)));
            config.setMaxIdle(Integer.parseInt(getResourceVal(maxIdle)));
            JedisPool jedisPool = new JedisPool(config, getResourceVal(host), Integer.parseInt(getResourceVal(port)));
            return jedisPool.getResource();
        }
    
        public static String getResourceVal(String key){ 
            if(resource.containsKey(key)){ 
                return (String) resource.get(key);
    
            }else{ 
                throw new RuntimeException("资源文件中找不到["+key+"]对应的值");
            }
        }
    }

redis配置文件redis.properties

redis.host=127.0.0.1
    redis.port=6379
    redis.maxTotal=20
    redis.maxIdle=10
    redis.remoteTime=60

运行结果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoaWFuZ195YW4_size_16_color_FFFFFF_t_70]

*  **温馨提示**

> 可以使用**Redis Desktop Manager**可视化客户端查看Redis数据  
> 链接：[https://pan.baidu.com/s/1Jhb3\_sAQo8vI-55drKv3sA][https_pan.baidu.com_s_1Jhb3_sAQo8vI-55drKv3sA]  
> 提取码：**6qzq**

--------------------

### \- 捐赠 - ###

--------------------

如果觉得还不错，请我喝杯水吧 ^ \_ ^ 您的鼓励是我不断前进的动力，如果有错误的地方，欢迎提出批评改正意见，[戳我][Link 1]，感谢您的支持

[Redis_-Windows_Linux]: https://blog.csdn.net/shiang_yan/article/details/106374531
[Redis]: https://blog.csdn.net/shiang_yan/article/details/106419289
[Redis_Java_Redis_Jedis]: https://blog.csdn.net/shiang_yan/article/details/106715945
[Redis_Redis]: https://blog.csdn.net/shiang_yan/article/details/106757561
[Redis_Redis_-multi_exec_discard]: https://blog.csdn.net/shiang_yan/article/details/106766022
[Redis 1]: https://blog.csdn.net/shiang_yan/article/details/106772467
[Redis_redis_-Bitmaps_HyperLogLog_GEO]: https://blog.csdn.net/shiang_yan/article/details/106781834
[Redis_redis_-]: https://blog.csdn.net/shiang_yan/article/details/106787637
[Redis_-]: https://blog.csdn.net/shiang_yan/article/details/106816943
[Redis_Redis_-]: https://blog.csdn.net/shiang_yan/article/details/106855953
[Redis_- 1]: https://blog.csdn.net/shiang_yan/article/details/106861236
[https_mvnrepository.com_artifact_redis.clients_jedis]: https://mvnrepository.com/artifact/redis.clients/jedis
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoaWFuZ195YW4_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20200615100133614.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoaWFuZ195YW4=,size_16,color_FFFFFF,t_70
[https_pan.baidu.com_s_1Jhb3_sAQo8vI-55drKv3sA]: https://pan.baidu.com/s/1Jhb3_sAQo8vI-55drKv3sA
[Link 1]: https://blog.csdn.net/shiang_yan