Java操作redis
Java操作redis很简单。创建一个普通的Java工程。然后导入redis依赖的jar包。jar包我已经上传了。
1.入门级的demo
package com.bjsxt.test; import redis.clients.jedis.Jedis; public class RedisDemo { public static Jedis getJedis(){ Jedis jedis = null; jedis = new Jedis(FinalCollention.IP, 6379); //redis服务器的ip和端口 jedis.auth(FinalCollention.PASSWORD); //连接redis的密码 return jedis; } public void test(){ Jedis jedis = null; try{ jedis = getJedis(); jedis.incr("test"); long dbsize = jedis.dbSize(); System.out.println("数据库大小:"+dbsize); System.out.println("测试test的值:"+jedis.get("test")); }catch(Exception e){ e.printStackTrace(); }finally{ if(jedis != null){ jedis.disconnect(); } } } public static void main(String[] args) { RedisDemo demo = new RedisDemo(); demo.test(); } }
如果出现Java无法连接redis的异常,主要有三个方面的问题:
1.Java运行的主机ping一下redis服务器所在主机,看能否ping通
2.关闭redis服务器所在主机的防火墙
3.打开redis安装目录下的redis.conf文件。注释掉:bind 127.0.0.1这句话
# Accept connections on the specified port, default is 6379. # If port 0 is specified Redis will not listen on a TCP socket. port 6379 # If you want you can bind a single interface, if the bind option is not # specified all the interfaces will listen for incoming connections. # # bind 127.0.0.1 "redis.conf" 597L, 25667C written
特别说明:后面的实例,我就不使用try--catch了,但是自己写时一定要记着关闭连接
2.Java操作redis的各种数据结构
package com.bjsxt.test; import java.util.HashMap; import java.util.List; import java.util.Map; import redis.clients.jedis.Jedis; public class RedisDataTypeDemo { public static Jedis getJedis(){ Jedis jedis = null; jedis = new Jedis(FinalCollention.IP, 6379); //redis服务器的ip和端口 jedis.auth(FinalCollention.PASSWORD); //连接redis的密码 return jedis; } /** * * @title demoKey * @description 测试Key * @author hadoop */ public void demoKey(){ Jedis jedis = RedisDataTypeDemo.getJedis(); System.out.println("查看键为aa的是否存在:"+jedis.exists("aa")); System.out.println("查看键为aa的类型:"+jedis.type("aa")); System.out.println("随机获得一个key:"+jedis.randomKey()); System.out.println("将aa重命名为bb:"+jedis.rename("aa", "bb")); System.out.println("删除bb:"+jedis.del("bb")); //从上面的方法可以看出,redis提供的接口方法名和redis-cli客户端提供的方法名是一样的,所以,只要对redis客户端的命令熟悉,那么Java操作redis就不是问题 } /** * * @title demoString * @description 测试String * @author hadoop */ public void demoString(){ Jedis jedis = RedisDataTypeDemo.getJedis(); System.out.println("设置name:"+jedis.set("name", "小花")); System.out.println("设置name1:"+jedis.set("name1", "小花1")); System.out.println("设置那么2:"+jedis.set("name2", "小花2")); System.out.println("设置name,如果存在返回0:"+jedis.setnx("name", "小花哈哈")); System.out.println("获取key为name和name1的value值:"+jedis.mget("name","name1")); System.out.println("自增1:"+jedis.incr("index")); System.out.println("自增1:"+jedis.incr("index")); System.out.println("自增2:"+jedis.incrBy("count", 2)); System.out.println("自增2:"+jedis.incrBy("count", 2)); System.out.println("递减1:"+jedis.decr("count")); System.out.println("递减2:"+jedis.decrBy("index",2)); System.out.println("在name后面添加String:"+jedis.append("name", ",我爱你")); System.out.println("获取key为name的值:"+jedis.get("name")); } /** * * @title demoList * @description 测试list数据类型 * @author hadoop */ public void demoList(){ Jedis jedis = RedisDataTypeDemo.getJedis(); //在头添加 jedis.lpush("list", "hadoop","hbase","hive","pig","zookeeper"); //在末尾添加 jedis.rpush("list", "java","struts"); //返回长度 jedis.llen("list"); //取值 Listlist = jedis.lrange("list", 0, -1); for (String string : list) { System.out.println(string); } } /** * * @title demoSet * @description 测试set数据类型 * @author hadoop */ public void demoSet(){ Jedis jedis = RedisDataTypeDemo.getJedis(); jedis.sadd("city", "北京","上海","重启","武汉"); System.out.println("取出最上面的:"+jedis.spop("city")); System.out.println("随机取出一个值"+jedis.srandmember("city")); jedis.sadd("city2", "北京","武汉","河北","张家界","辽林"); System.out.println("交集:"+jedis.sinter("city","city1")); System.out.println("并集:"+jedis.sunion("city","city1")); System.out.println("差集:"+jedis.sdiff("city","city1")); } /** * * @title demoMap * @description 测试map数据类型 * @author hadoop */ public void demoMap(){ Jedis jedis = RedisDataTypeDemo.getJedis(); jedis.hset("Mcity", "c1", "北京"); System.out.println("取值:"+jedis.hget("city", "c1")); Map mcity = new HashMap (); mcity.put("c1", "桂林"); mcity.put("c2", "天津"); mcity.put("c3", "合肥"); jedis.hmset("Mcity2", mcity); List list = jedis.hmget("Mcity2", "c1","c2","c3"); for (String string : list) { System.out.println(string); } System.out.println(jedis.hlen("Mcity2")); } //测试 public static void main(String[] args) { RedisDataTypeDemo rdr = new RedisDataTypeDemo(); rdr.demoKey(); rdr.demoList(); rdr.demoMap(); rdr.demoSet(); rdr.demoString(); } }
3.Java操作redis的管道
package com.bjsxt.test; import redis.clients.jedis.Jedis; import redis.clients.jedis.Pipeline; public class RedisPipelineDemo { public static Jedis getJedis(){ Jedis jedis = null; jedis = new Jedis(FinalCollention.IP, 6379); //redis服务器的ip和端口 jedis.auth(FinalCollention.PASSWORD); //连接redis的密码 return jedis; } public void hasPipeline(){ Jedis jedis = RedisPipelineDemo.getJedis(); System.out.println("开始:"+System.currentTimeMillis()); Pipeline pl = jedis.pipelined(); for(int i = 0 ; i < 1000 ; i++){ pl.incr("testPL"); } pl.sync(); System.out.println("开始:"+System.currentTimeMillis()); } public void noPipeline(){ Jedis jedis = RedisPipelineDemo.getJedis(); System.out.println("开始:"+System.currentTimeMillis()); for(int i = 0 ; i < 1000 ; i++){ jedis.incr("testPL"); } System.out.println("开始:"+System.currentTimeMillis()); } }
4.redis事务
package com.bjsxt.test; import java.util.List; import redis.clients.jedis.Jedis; import redis.clients.jedis.Transaction; public class RedisTXDemo { public static Jedis getJedis(){ Jedis jedis = null; jedis = new Jedis(FinalCollention.IP, 6379); //redis服务器的ip和端口 jedis.auth(FinalCollention.PASSWORD); //连接redis的密码 return jedis; } /** * * @title txDemo * @description 没有异常的事务 * @author hadoop */ public void txDemo(){ Jedis jedis = getJedis(); //开启事务 Transaction tx = jedis.multi(); tx.set("txcity", "beijin"); tx.sadd("hi", "abc"); tx.get("txcity"); List
从上面的方法可以看出,redis提供的接口方法名和redis-cli客户端提供的方法名是一样的,所以,只要对redis客户端的命令熟悉,那么Java操作redis就不是问题