笔记内容来自B站博主《遇见狂神说》:Redis视频链接
Jedis 是一个用于 Java 的 Redis 客户端库,它提供了一组 API 用于与 Redis 数据库进行交互。Redis 是一个高性能的键值存储数据库,广泛用于缓存、消息队列等场景。Jedis 使得 Java 开发者能够方便地与 Redis 进行通信,执行 Redis 命令,并操作 Redis 数据结构。
1、简单了解Jedis
SpringBoot 引入 Jedis
pom.xml
java
<dependencies>
<!-- jedis -->
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>4.2.3</version>
</dependency>
<!-- fastjson -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>2.0.49</version>
</dependency>
</dependencies>
Jedis源码
可以进入 Jedis 源码看一下,Jedis 构造函数还是挺多的,一般我们用的也就是ip+端口号。
jedis.class
2、代码测试
连接数据库
java
package oldfe.study;
import redis.clients.jedis.Jedis;
public class Main {
public static void main(String[] args) {
// 1、 new Jedis 对象
Jedis jedis = new Jedis("127.0.0.1", 6379);
// 2、如果设置密码,需要 auth方法进行密码认证
jedis.auth("123456");
// 3、ping
System.out.println(jedis.ping());
jedis.close(); // 关闭连接
}
}
输出:
返回表示 PONG 已经连接上
常用 API
基本API
java
package oldfe.study;
import redis.clients.jedis.Jedis;
import java.util.Set;
public class Main {
public static void main(String[] args) {
Jedis jedis = new Jedis("127.0.0.1", 6379);
jedis.auth("123456");
System.out.printf("清空全部数据库:%s %n", jedis.flushAll());
System.out.printf("清空当前数据库:%s %n", jedis.flushDB());
System.out.printf("判断某个键是否存在:%s %n", jedis.exists("name"));
System.out.printf("新增<'name', 'OldFe'>键值对::%s %n", jedis.set("name", "OldFe"));
System.out.printf("新增<'age', '16'>键值对::%s %n", jedis.set("age", "16"));
System.out.printf("在集合的键值列表头部插入一个值:%s %n", jedis.lpush("listKey", "listValue"));
System.out.printf("系统中所有的键如下:");
Set<String> keys = jedis.keys("*");
System.out.println(keys);
System.out.printf("删除键age:%s %n", jedis.del("age"));
System.out.printf("判断键age是否存在: %s %n", jedis.exists("age"));
System.out.printf("判断键name所储存的值的类型: %s %n", jedis.type("name"));
System.out.printf("判断键listKey所储存的值的类型: %s %n", jedis.type("listKey"));
System.out.printf("随机返回可以空间的一个: %s %n", jedis.randomKey());
System.out.printf("重命名键name为name1: %s %n", jedis.rename("name", "name1"));
System.out.printf("返回键name1的值: %s %n", jedis.get("name1"));
System.out.printf("按索引查询第1个数据库: %s %n", jedis.select(0)); // Redis 一共有16个数据库(索引下标:0-15)
System.out.printf("返回当前数据库的键: %s %n", jedis.keys("*"));
System.out.printf("返回当前数据库键的数目: %s %n", jedis.dbSize());
}
}
// 输出:
清空全部数据库:OK
清空当前数据库:OK
判断某个键是否存在:false
新增<'name', 'OldFe'>键值对::OK
新增<'age', '16'>键值对::OK
在集合的键值列表头部插入一个值:1
系统中所有的键如下:[name, listKey, age]
删除键age:1
判断键age是否存在: false
判断键name所储存的值的类型: string
判断键listKey所储存的值的类型: list
随机返回可以空间的一个: listKey
重命名键name为name1: OK
返回键name1的值: OldFe
按索引查询第1个数据库: OK
返回当前数据库的键: [name1, listKey]
返回当前数据库键的数目: 2
字符串 String
java
package oldfe.study;
import redis.clients.jedis.Jedis;
import java.util.concurrent.TimeUnit;
public class TestString {
public static void main(String[] args) {
Jedis jedis = new Jedis("127.0.0.1", 6379);
jedis.auth("123456");
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));
}
}
// 输出:
===========增加数据===========
OK
OK
OK
删除键key2:1
获取键key2:null
修改key1:OK
获取key1的值:value1Changed
在key3后面加入值:9
key3的值:value3End
增加多个键值对:OK
获取多个键值对:[value01, value02, value03]
获取多个键值对:[value01, value02, value03, null]
删除多个键值对:2
获取多个键值对:[null, null, value03]
===========新增键值对防止覆盖原先值==============
1
1
0
value1
value2
===========新增键值对并设置有效时间=============
OK
value3
null
===========获取原值,更新为新值==========
value2
key2GetSet
获得key2的值的字串:y2G
列表 List
java
package oldfe.study;
import redis.clients.jedis.Jedis;
public class TestList {
public static void main(String[] args) {
Jedis jedis = new Jedis("127.0.0.1", 6379);
jedis.auth("123456");
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));
}
}
// 输出:
===========添加一个list===========
collections的内容:[TreeMap, TreeSet, HashSet, LinkedHashMap, WeakHashMap, HashMap, Stack, Vector, ArrayList]
collections区间0-3的元素:[TreeMap, TreeSet, HashSet, LinkedHashMap]
===============================
删除指定元素个数:1
collections的内容:[TreeMap, TreeSet, HashSet, LinkedHashMap, WeakHashMap, Stack, Vector, ArrayList]
删除下表0-3区间之外的元素:OK
collections的内容:[TreeMap, TreeSet, HashSet, LinkedHashMap]
collections列表出栈(左端):TreeMap
collections的内容:[TreeSet, HashSet, LinkedHashMap]
collections添加元素,从列表右端,与lpush相对应:4
collections的内容:[TreeSet, HashSet, LinkedHashMap, EnumMap]
collections列表出栈(右端):EnumMap
collections的内容:[TreeSet, HashSet, LinkedHashMap]
修改collections指定下标1的内容:OK
collections的内容:[TreeSet, LinkedArrayList, LinkedHashMap]
===============================
collections的长度:3
获取collections下标为2的元素:LinkedHashMap
===============================
sortedList排序前:[4, 7, 0, 2, 6, 3]
[0, 2, 3, 4, 6, 7]
sortedList排序后:[4, 7, 0, 2, 6, 3]
集合 Set
java
package oldfe.study;
import redis.clients.jedis.Jedis;
public class TestSet {
public static void main(String[] args) {
Jedis jedis = new Jedis("127.0.0.1", 6379);
jedis.auth("123456");
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"));
}
}
// 输出:
============向集合中添加元素(不重复)============
8
1
0
eleSet的所有元素为:[e5, e6, e7, e8, e0, e1, e2, e3, e4]
删除一个元素e0:1
eleSet的所有元素为:[e5, e6, e7, e8, e1, e2, e3, e4]
删除两个元素e7和e6:2
eleSet的所有元素为:[e5, e8, e1, e2, e3, e4]
随机的移除集合中的一个元素:e5
随机的移除集合中的一个元素:e1
eleSet的所有元素为:[e2, e3, e4, e8]
eleSet中包含元素的个数:4
e3是否在eleSet中:true
e1是否在eleSet中:false
e1是否在eleSet中:false
=================================
8
6
将eleSet1中删除e1并存入eleSet3中:1
将eleSet1中删除e2并存入eleSet3中:1
eleSet1中的元素:[e5, e7, e0, e8, e3, e4]
eleSet3中的元素:[e1, e2]
============集合运算=================
eleSet1中的元素:[e5, e7, e0, e8, e3, e4]
eleSet2中的元素:[e0, e8, e1, e2, e3, e4]
eleSet1和eleSet2的交集:[e3, e4, e0, e8]
eleSet1和eleSet2的并集:[e5, e7, e0, e8, e1, e2, e3, e4]
eleSet1和eleSet2的差集:[e7, e5]
eleSet4中的元素:[e3, e4, e0, e8]
哈希 Hash
java
package oldfe.study;
import redis.clients.jedis.Jedis;
import java.util.HashMap;
import java.util.Map;
public class TestHash {
public static void main(String[] args) {
Jedis jedis = new Jedis("127.0.0.1", 6379);
jedis.auth("123456");
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"));
}
}
// 输出:
散列hash的所有键值对为:{key1=value1, key2=value2, key5=value5, key3=value3, key4=value4}
散列hash的所有键为:[key1, key2, key5, key3, key4]
散列hash的所有值为:[value1, value2, value3, value4, value5]
将key6保存的值加上一个整数,如果key6不存在则添加key6:6
散列hash的所有键值对为:{key1=value1, key2=value2, key5=value5, key6=6, key3=value3, key4=value4}
将key6保存的值加上一个整数,如果key6不存在则添加key6:9
散列hash的所有键值对为:{key1=value1, key2=value2, key5=value5, key6=9, key3=value3, key4=value4}
删除一个或者多个键值对:1
散列hash的所有键值对为:{key1=value1, key5=value5, key6=9, key3=value3, key4=value4}
散列hash中键值对的个数:5
判断hash中是否存在key2:false
判断hash中是否存在key3:true
获取hash中的值:[value3]
获取hash中的值:[value3, value4]