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  • Jedis

    万次阅读 2021-01-17 00:26:10
    Jedis前言什么是Jedis为什么要使用Jedis1、导入对应的依赖2、编码测试3、常用的API3.1 String3.2 List3.3 Set3.4 Hash3.5 Key3.6 Password4、通过Jedis再次理解 事务 前言 提示:本文章是日常学习内容的总结,并非...

    前言

    提示:本文章是日常学习内容的总结,并非全部原创;仅供大家参考借鉴,并无其他商业用途。Bilibili搜索关注:狂神说
    真正在公司中的实践:NoSQL + RDBMS 一起使用才是最强的,阿里巴巴的架构演进!
    技术没有高低之分,就看你如何去使用!(提升内功,思维的提高!)
    云计算的长征之路:阿里云的这群疯子

    什么是Jedis

    是Jedis 是 Redis 官方推荐的 java连接开发工具!
    是使用Java 操作Redis 中间件!
    如果你要使用java去操作redis
    那么一定要对Jedis 十分的熟悉!

    为什么要使用Jedis

    知其然并知其所以然,授人以渔! 学习不能急躁,慢慢来会很快!
    先了解Jedis,再用spring-data-redis去整合
    所以我们要先使用 Java 来操作 Redis,

    1、导入对应的依赖

    <!--导入jedis的包-->
    <dependencies>
        <!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>3.2.0</version>
        </dependency>
        <!--fastjson-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.62</version>
        </dependency>
    </dependencies>
    

    2、编码测试

    1. 连接数据库
    2. 操作命令
    3. 断开连接!

    package com.kuang;
    
    import redis.clients.jedis.Jedis;
    
    public class TestPing {
        public static void main(String[] args) {
        // new Jedis 对象即可
        Jedis jedis = new Jedis("127.0.0.1",6379);
        // jedis 所有的命令就是redis-cli客户端的所有指令!
    
        System.out.println(jedis.ping());
        }
    }
    

    4. 输出

    在这里插入图片描述

    3、常用的API

    所有的api命令,都对应前面文章的五大数据类型的指令,一个都没有变化!

    3.1 String

     public static void main(String[] args) {
            Jedis jedis = new Jedis("127.0.0.1", 6379);
    
            jedis.flushDB();
            System.out.println("===========增加数据===========");
            System.out.println(jedis.set("key1","value1"));
            System.out.println(jedis.set("key2","value2"));
            System.out.println(jedis.set("key3", "value3"));
            System.out.println("删除键key2:"+jedis.del("key2"));
            System.out.println("获取键key2:"+jedis.get("key2"));
            System.out.println("修改key1:"+jedis.set("key1", "value1Changed"));
            System.out.println("获取key1的值:"+jedis.get("key1"));
            System.out.println("在key3后面加入值:"+jedis.append("key3", "End"));
            System.out.println("key3的值:"+jedis.get("key3"));
            System.out.println("增加多个键值对:"+jedis.mset("key01","value01","key02","value02","key03","value03"));
            System.out.println("获取多个键值对:"+jedis.mget("key01","key02","key03"));
            System.out.println("获取多个键值对:"+jedis.mget("key01","key02","key03","key04"));
            System.out.println("删除多个键值对:"+jedis.del("key01","key02"));
            System.out.println("获取多个键值对:"+jedis.mget("key01","key02","key03"));
    
            jedis.flushDB();
            System.out.println("===========新增键值对防止覆盖原先值==============");
            System.out.println(jedis.setnx("key1", "value1"));
            System.out.println(jedis.setnx("key2", "value2"));
            System.out.println(jedis.setnx("key2", "value2-new"));
            System.out.println(jedis.get("key1"));
            System.out.println(jedis.get("key2"));
    
            System.out.println("===========新增键值对并设置有效时间=============");
            System.out.println(jedis.setex("key3", 2, "value3"));
            System.out.println(jedis.get("key3"));
            try {
                TimeUnit.SECONDS.sleep(3);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(jedis.get("key3"));
    
            System.out.println("===========获取原值,更新为新值==========");
            System.out.println(jedis.getSet("key2", "key2GetSet"));
            System.out.println(jedis.get("key2"));
    
            System.out.println("获得key2的值的字串:"+jedis.getrange("key2", 2, 4));
        }
    

    3.2 List

        public static void main(String[] args) {
            Jedis jedis = new Jedis("127.0.0.1", 6379);
            jedis.flushDB();
            System.out.println("===========添加一个list===========");
            jedis.lpush("collections", "ArrayList", "Vector", "Stack", "HashMap", "WeakHashMap", "LinkedHashMap");
            jedis.lpush("collections", "HashSet");
            jedis.lpush("collections", "TreeSet");
            jedis.lpush("collections", "TreeMap");
            System.out.println("collections的内容:"+jedis.lrange("collections", 0, -1));//-1代表倒数第一个元素,-2代表倒数第二个元素,end为-1表示查询全部
            System.out.println("collections区间0-3的元素:"+jedis.lrange("collections",0,3));
            System.out.println("===============================");
            // 删除列表指定的值 ,第二个参数为删除的个数(有重复时),后add进去的值先被删,类似于出栈
            System.out.println("删除指定元素个数:"+jedis.lrem("collections", 2, "HashMap"));
            System.out.println("collections的内容:"+jedis.lrange("collections", 0, -1));
            System.out.println("删除下表0-3区间之外的元素:"+jedis.ltrim("collections", 0, 3));
            System.out.println("collections的内容:"+jedis.lrange("collections", 0, -1));
            System.out.println("collections列表出栈(左端):"+jedis.lpop("collections"));
            System.out.println("collections的内容:"+jedis.lrange("collections", 0, -1));
            System.out.println("collections添加元素,从列表右端,与lpush相对应:"+jedis.rpush("collections", "EnumMap"));
            System.out.println("collections的内容:"+jedis.lrange("collections", 0, -1));
            System.out.println("collections列表出栈(右端):"+jedis.rpop("collections"));
            System.out.println("collections的内容:"+jedis.lrange("collections", 0, -1));
            System.out.println("修改collections指定下标1的内容:"+jedis.lset("collections", 1, "LinkedArrayList"));
            System.out.println("collections的内容:"+jedis.lrange("collections", 0, -1));
            System.out.println("===============================");
            System.out.println("collections的长度:"+jedis.llen("collections"));
            System.out.println("获取collections下标为2的元素:"+jedis.lindex("collections", 2));
            System.out.println("===============================");
            jedis.lpush("sortedList", "3","6","2","0","7","4");
            System.out.println("sortedList排序前:"+jedis.lrange("sortedList", 0, -1));
            System.out.println(jedis.sort("sortedList"));
            System.out.println("sortedList排序后:"+jedis.lrange("sortedList", 0, -1));
        }
    

    3.3 Set

     public static void main(String[] args) {
            Jedis jedis = new Jedis("127.0.0.1", 6379);
            jedis.flushDB();
            System.out.println("============向集合中添加元素(不重复)============");
            System.out.println(jedis.sadd("eleSet", "e1","e2","e4","e3","e0","e8","e7","e5"));
            System.out.println(jedis.sadd("eleSet", "e6"));
            System.out.println(jedis.sadd("eleSet", "e6"));
            System.out.println("eleSet的所有元素为:"+jedis.smembers("eleSet"));
            System.out.println("删除一个元素e0:"+jedis.srem("eleSet", "e0"));
            System.out.println("eleSet的所有元素为:"+jedis.smembers("eleSet"));
            System.out.println("删除两个元素e7和e6:"+jedis.srem("eleSet", "e7","e6"));
            System.out.println("eleSet的所有元素为:"+jedis.smembers("eleSet"));
            System.out.println("随机的移除集合中的一个元素:"+jedis.spop("eleSet"));
            System.out.println("随机的移除集合中的一个元素:"+jedis.spop("eleSet"));
            System.out.println("eleSet的所有元素为:"+jedis.smembers("eleSet"));
            System.out.println("eleSet中包含元素的个数:"+jedis.scard("eleSet"));
            System.out.println("e3是否在eleSet中:"+jedis.sismember("eleSet", "e3"));
            System.out.println("e1是否在eleSet中:"+jedis.sismember("eleSet", "e1"));
            System.out.println("e1是否在eleSet中:"+jedis.sismember("eleSet", "e5"));
            System.out.println("=================================");
            System.out.println(jedis.sadd("eleSet1", "e1","e2","e4","e3","e0","e8","e7","e5"));
            System.out.println(jedis.sadd("eleSet2", "e1","e2","e4","e3","e0","e8"));
            //移到集合元素
            System.out.println("将eleSet1中删除e1并存入eleSet3中:"+jedis.smove("eleSet1", "eleSet3", "e1"));
            System.out.println("将eleSet1中删除e2并存入eleSet3中:"+jedis.smove("eleSet1", "eleSet3", "e2"));
            System.out.println("eleSet1中的元素:"+jedis.smembers("eleSet1"));
            System.out.println("eleSet3中的元素:"+jedis.smembers("eleSet3"));
            System.out.println("============集合运算=================");
            System.out.println("eleSet1中的元素:"+jedis.smembers("eleSet1"));
            System.out.println("eleSet2中的元素:"+jedis.smembers("eleSet2"));
            System.out.println("eleSet1和eleSet2的交集:"+jedis.sinter("eleSet1","eleSet2"));
            System.out.println("eleSet1和eleSet2的并集:"+jedis.sunion("eleSet1","eleSet2"));
            System.out.println("eleSet1和eleSet2的差集:"+jedis.sdiff("eleSet1","eleSet2"));//eleSet1中有,eleSet2中没有
            jedis.sinterstore("eleSet4","eleSet1","eleSet2");//求交集并将交集保存到dstkey的集合
            System.out.println("eleSet4中的元素:"+jedis.smembers("eleSet4"));
        }
    

    3.4 Hash

     public static void main(String[] args) {
            Jedis jedis = new Jedis("127.0.0.1", 6379);
            jedis.flushDB();
            Map<String,String> map = new HashMap<String,String>();
            map.put("key1","value1");
            map.put("key2","value2");
            map.put("key3","value3");
            map.put("key4","value4");
            //添加名称为hash(key)的hash元素
            jedis.hmset("hash",map);
            //向名称为hash的hash中添加key为key5,value为value5元素
            jedis.hset("hash", "key5", "value5");
            System.out.println("散列hash的所有键值对为:"+jedis.hgetAll("hash"));//return Map<String,String>
            System.out.println("散列hash的所有键为:"+jedis.hkeys("hash"));//return Set<String>
            System.out.println("散列hash的所有值为:"+jedis.hvals("hash"));//return List<String>
            System.out.println("将key6保存的值加上一个整数,如果key6不存在则添加key6:"+jedis.hincrBy("hash", "key6", 6));
            System.out.println("散列hash的所有键值对为:"+jedis.hgetAll("hash"));
            System.out.println("将key6保存的值加上一个整数,如果key6不存在则添加key6:"+jedis.hincrBy("hash", "key6", 3));
            System.out.println("散列hash的所有键值对为:"+jedis.hgetAll("hash"));
            System.out.println("删除一个或者多个键值对:"+jedis.hdel("hash", "key2"));
            System.out.println("散列hash的所有键值对为:"+jedis.hgetAll("hash"));
            System.out.println("散列hash中键值对的个数:"+jedis.hlen("hash"));
            System.out.println("判断hash中是否存在key2:"+jedis.hexists("hash","key2"));
            System.out.println("判断hash中是否存在key3:"+jedis.hexists("hash","key3"));
            System.out.println("获取hash中的值:"+jedis.hmget("hash","key3"));
            System.out.println("获取hash中的值:"+jedis.hmget("hash","key3","key4"));
        }
    

    3.5 Key

    public static void main(String[] args) {
            Jedis jedis = new Jedis("127.0.0.1", 6379);
    
            System.out.println("清空数据:"+jedis.flushDB());
            System.out.println("判断某个键是否存在:"+jedis.exists("username"));
            System.out.println("新增<'username','kuangshen'>的键值对:"+jedis.set("username", "kuangshen"));
            System.out.println("新增<'password','password'>的键值对:"+jedis.set("password", "password"));
            System.out.print("系统中所有的键如下:");
            Set<String> keys = jedis.keys("*");
            System.out.println(keys);
            System.out.println("删除键password:"+jedis.del("password"));
            System.out.println("判断键password是否存在:"+jedis.exists("password"));
            System.out.println("查看键username所存储的值的类型:"+jedis.type("username"));
            System.out.println("随机返回key空间的一个:"+jedis.randomKey());
            System.out.println("重命名key:"+jedis.rename("username","name"));
            System.out.println("取出改后的name:"+jedis.get("name"));
            System.out.println("按索引查询:"+jedis.select(0));
            System.out.println("删除当前选择数据库中的所有key:"+jedis.flushDB());
            System.out.println("返回当前数据库中key的数目:"+jedis.dbSize());
            System.out.println("删除所有数据库中的所有key:"+jedis.flushAll());
        }
    

    3.6 Password

    public static void main(String[] args) {
            Jedis jedis = new Jedis("127.0.0.1", 6379);
    
            //验证密码,如果没有设置密码这段代码省略
            //jedis.auth("password");
            jedis.connect(); //连接
            jedis.disconnect(); //断开连接
            jedis.flushAll(); //清空所有的key
        }
    

    4、通过Jedis再次理解 事务

     public static void main(String[] args) {
            //创建客户端连接服务端,redis服务端需要被开启
            Jedis jedis = new Jedis("127.0.0.1", 6379);
            jedis.flushDB();
    
            JSONObject jsonObject = new JSONObject();
            jsonObject.put("hello", "world");
            jsonObject.put("name", "java");
    
            //开启事务
            Transaction multi = jedis.multi();
            String result = jsonObject.toJSONString();
            try{
                //向redis存入一条数据
                multi.set("json", result);
                //再存入一条数据
                multi.set("json2", result);
                //故意引发ArithmeticException: / by zero异常
                int i = 100/0;
                //如果没有引发异常,执行进入队列的命令
                multi.exec();
            }catch(Exception e){
                e.printStackTrace();
                //如果出现异常,回滚
                multi.discard();
            }finally{
                System.out.println(jedis.get("json"));
                System.out.println(jedis.get("json2"));
                //最终关闭客户端
                jedis.close();
            }
        }
    

    结果:由于异常,事务回滚。json,json2没有执行成功,返回null。

    java.lang.ArithmeticException: / by zero
    	at com.kuang.multi.TestMulti.main(TestMulti.java:26)
    null
    null
    
    
    展开全文
  • jedis

    2019-05-06 20:30:45
    package com.imooc.jedis; import org.junit.Test;...import redis.clients.jedis.Jedis; import redis.clients.jedis.JedisPool; import redis.clients.jedis.JedisPoolConfig; public class JedisDemo1 { /**...
    package com.imooc.jedis;
    
    import org.junit.Test;
    
    import redis.clients.jedis.Jedis;
    import redis.clients.jedis.JedisPool;
    import redis.clients.jedis.JedisPoolConfig;
    
    public class JedisDemo1 {
    	
    	/**
    	 * jedis测试
    	 */
    	@Test
    	public void demo01() {
    		//1.设置IP地址和端口
    		Jedis jedis = new Jedis("192.168.2.128",6379);
    		//2.保存数据
    		jedis.set("name", "zhangsan");
    		//3.获取数据
    		String value = jedis.get("name");
    		System.out.println(value);
    		//4.释放资源
    		jedis.close();
    	}
    	/**
    	 * 连接池连接方式
    	 */
    	@Test
    	public void demo02() {
    		//获得连接池的配置对象
    		JedisPoolConfig config = new JedisPoolConfig();
    		//设置最大连接数
    		config.setMaxTotal(30);
    		//设置最大空闲连接数
    		config.setMaxIdle(10);
    		
    		//获取连接池
    		JedisPool jedispool = new JedisPool(config, "192.168.2.128", 6379);
    		Jedis jedis = null;
    		try {
    			//获取核心对象
    			jedis = jedispool.getResource();
    			//设置数据
    			jedis.set("name", "张三");
    			//获取数据
    			String value = jedis.get("name");
    			System.out.println(value);		
    		}catch(Exception e) {
    			e.printStackTrace();
    		}finally {
    			if(jedis != null) {
    				jedis.close();
    			}
    			if(jedispool != null) {
    				jedispool.close();
    			}
    		}
    	}
    }

    注意事项:

    1、Java建立简单的测试单元,但是运行时会报错,因为linux中没有将6379端口打开。

    2、vim /etc/sysconfig/iptables。yy复制22端口那一行,p粘贴修改为6379。

    3、重启防火墙service iptables restart

    jedis需要的jar包

    commons-pool2-2.3.jar

    jedis-2.7.0.jar

    链接:https://pan.baidu.com/s/1SmoofHfS-dFcnhKC8nQZ9Q 
    提取码:0of7 

    展开全文

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