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
        List<String> list = 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<String,String> mcity = new HashMap<String, String>();
        mcity.put("c1", "桂林");
        mcity.put("c2", "天津");
        mcity.put("c3", "合肥");
        jedis.hmset("Mcity2", mcity);
        List<String> 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<Object> objs = tx.exec();

        for (Object object : objs) {
            System.out.println(object.toString());
        }
    }

    /**
     *
     * @title txHasExDemo
     * @description 含有异常的事务
     * @author hadoop
     */
    public void txHasExDemo(){
        Jedis jedis = getJedis();
        //开启事务
        Transaction tx = jedis.multi();

        tx.set("txcity1", "beijin");
        tx.sadd("hi1", "abc");
        int i = 1/0;
        tx.get("txcity1");
        List<Object> objs = tx.exec();

        for (Object object : objs) {
            System.out.println(object.toString());
        }
    }

    public static void main(String[] args) {
        RedisTXDemo redisTXDemo = new RedisTXDemo();
        redisTXDemo.txDemo();
        redisTXDemo.txHasExDemo();
    }
}

 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