Redis缓存Mysql模拟用户登录Java实现实例

这段时间在研究Redis，作为缓存界的新宠，现在使用它的公司越来越多。本文使用的是最新稳定版Redis3.0.实现的具体逻辑是：

    1. 用户登录首先判断是否在redis缓存中，如果在redis缓存中，直接登录成功；

    2. 若用户未在redis缓存，则访问Mysql，判断用户是否存在，如果不存在，则提示用户注册；如果存在，则登录成功；

    3. 在mysql存在并登录成功的同时，将改条数据用Redis Hash类型进行缓存，并设置过期时间为30分钟；

    4. 设置redis最大内存，若超出内存范围，则使用FIFO方式进行清除。

本文实现方式为最简单的模拟方式，有的代码有进一步封装得必要。

工具/原料

Redis,Mysql

Java

方法/步骤

一、首先创建两个类，一个类连接Mysql，一个类连接Redis，并复写相关方法：

public class Mysql {

         public Connection conn;

         {

                 try {

                          Class.forName("com.mysql.jdbc.Driver");

                          conn=DriverManager.getConnection("jdbc:mysql://localhost/spring","root","root");

                 } catch (ClassNotFoundException e) {

                          e.printStackTrace();

                 } catch (SQLException e) {

                          e.printStackTrace();

                 }

         }

 

}

public class Redis extends Jedis {

 

         public Jedis redis;

         {

                 redis = new Jedis("192.168.217.128", 6379);

                 redis.auth("root");

         }

 

         // public static void main(String[] args) {

         // System.out.println(redis.get("name"));

         // System.out.println(redis.keys("*"));

         // // redis.sinter(keys);

         // }

 

         public String get(String key) {

                 return redis.get("name");

         }

 

         public String set(String key, String value) {

                 return redis.set(key, value);

         }

 

         public Long del(String... keys) {

                 return redis.del(keys);

         }

 

         // 键值增加字符

         public Long append(String key, String str) {

                 return redis.append(key, str);

         }

 

         public Boolean exists(String key) {

                 return redis.exists(key);

         }

 

         // Need research

         public Long setnx(String key, String value) {

                 return redis.setnx(key, value);

         }

 

         public String setex(String key, String value, int seconds) {

                 return redis.setex(key, seconds, value);

         }

 

         public Long setrange(String key, String str, int offset) {

                 return redis.setrange(key, offset, str);

         }

 

         public List<String> mget(String... keys) {

                 return redis.mget(keys);

         }

 

         public String mset(String... keys) {

                 return redis.mset(keys);

         }

 

         public Long msetnx(String... keysvalues) {

                 return redis.msetnx(keysvalues);

         }

 

         public String getset(String key, String value) {

                 return redis.getSet(key, value);

         }

 

         public String hmset(String key, Map<String, String> hash) {

                 return redis.hmset(key, hash);

         }

 

         public Map<String, String> hgetall(String key) {

                 return redis.hgetAll(key);

         }

 

         public String hget(final String key, final String field) {

                 return redis.hget(key, field);

         }

 

         public Long hset(final String key, final String field, final String value) {

                 return redis.hset(key, field, value);

         }

 

         public Long expire(final String key, final int seconds) {

                 return redis.expire(key, seconds);

         }

 

         public Boolean hexists(final String key, final String field) {

                 return redis.hexists(key, field);

         }

 

}

二、逻辑具体实现：

public class Main {

         Mysql mysql=new Mysql();

         Redis redis=new Redis();

         ResultSet rs=null;

        

         //模拟登陆缓存

         @Test

         public void redisLogin() throws SQLException{

                 //正常业务的ID是通过UI的request.getParamenter()获取

                 String id="9028935b527d22cc01527d235aea0142";

                 String sql="select * from user where id_='"+id+"'";

                 String username;

                 if(redis.hexists("user_"+id, "username_")){

                          username=redis.hget("user_"+id, "username_");

                          System.out.println("Welcome Redis! User "+username+" login success");

                 }else{

                          rs=mysql.conn.createStatement().executeQuery(sql);

                          if(rs.next()==false){

                                   System.out.println("Mysql no register, Please register first");

                          }else{

                                   username=rs.getString("username_");

                                   System.out.println("Welcome Mysql ! User "+username+" login success");

                                   redis.hset("user_"+id, "username_", username);

                                   //30分钟未操作就过期

                                   redis.expire("user_"+id, 1800);

                          }

                 }

                

         }

}

以下是运行结果截图：














4

三、 设置最大内存：

在redis.conf文件中找到并设置即可：

 maxmemory  10240000

来自：http://jingyan.baidu.com/article/09ea3ede1dd0f0c0aede3938.html