• 7.Jedis


    Jedis

    使用java来操作Redis

    什么是Jedis ?
    Redis官方推荐的java连接开发工具

    测试

    1. 导入对应依赖
    <!-- https://mvnrepository.com/artifact/redis.clients/jedis -->
    <dependency>
        <groupId>redis.clients</groupId>
        <artifactId>jedis</artifactId>
        <version>2.9.0</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.74</version>
    </dependency>
    
    1. 编码测试
    • 连接数据库
    • 操作命令
    • 断开连接
    public class TestPing {
        public static void main(String[] args) {
            // 1. new Jedis对象
            Jedis jedis = new Jedis("127.0.0.1", 6379);
            System.out.println(jedis.ping());
        }
    }
    

    输出:
    在这里插入图片描述

    常用API


    String

    public class TestString {
        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));
        }
    

    List

    public class TestList {
        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));
        }
    }
    

    Set

    public class TestSet {
        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"));
            System.out.println("将eleSet1中删除e1并存入eleSet3中:"+jedis.smove("eleSet1", "eleSet3", "e1"));//移到集合元素
            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"));
        }
    }
    

    Hash

    public class TestHash {
        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"));
        }
    }
    

    Zset

    事务

    public class TestMulti {
        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);
                //这里引发了异常,用0作为被除数
                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();
            }
        }
    }
    
  • 相关阅读:
    ./configure时候遇到的问题 Cannot find install-sh, install.sh, or shtool in ac-aux
    携程ELK
    操作系统日志分析中常见的搜索条目 20160715
    日志分析方法
    通过UUID方式在fstab中挂载分区
    Linux上查看造成IO高负载的进程
    Logstash 最佳实践
    使用sqlplus执行sql时,发现有中文有乱码解决方法
    Nginx模块GeoIP匹配处理IP所在国家、城市
    《iOS Human Interface Guidelines》——Segmented Control
  • 原文地址:https://www.cnblogs.com/PythonFCG/p/13859879.html
Copyright © 2020-2023  润新知