Java秒杀系统方案优化

Java秒杀系统方案优化

搭建项目

使用spring boot搭建项目建立相关的包名、类名。

mybatis的相关配置

1.加入mybatis相关的依赖
2.在application.properties配置文件中写配置mybatis相关的代码

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/miaosha?useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=123456789

3.测试数据库是否连接，相应的dao层代码

@Mapper
public interface UserDao {
    
    @Select("select * from user where id=#{id}")
    List <User> getById(@Param("id")int id);
}

controller层相应的代码如下

    @RequestMapping("/redis/get")
    @ResponseBody
    public Result<User> redisGet(){
        User user = redisService.get(UserKey.getById, ""+1, User.class);
        return Result.success(user);
    }

Redis相关的配置和安装

1. 阿里云服务器安装redis
2. 安装redis镜像: Docker pull redis

3. 启动redis镜像：docker run -p 6379:6379--name redis -d redis:latest  --requirepass “123456” 	
    进入redis镜像：docker exec -it redis redis-cli -a 123456 	
     添加数据：set name xiaomianyang 	
     读取数据：get name
   

4. 使用可视化工具(RedisDesktopManager) 建立远程连接
5. 使用idea远程使用redis
6. Maven配置

       <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
        </dependency>

7. 和搭建Mybatis一样相关的配置信息也是存放在properties上的，相关代码如下：

redis.host=182.92.170.161
redis.port=6379
redis.timeout=3
redis.password=123456
redis.poolMaxTotal=10
redis.poolMaxIdle=10
redis.poolMaxWait=3

8. 编写bean来获取配置信息，代码如下：

@Component
@ConfigurationProperties(prefix = "redis")
public class RedisConfig {
    private String host;
    private int port;
    private int timeout;
    private String password;
    private int poolMaxTotal;

[email protected](把properties中redis开头的信息注入到相关的属性中)

9. 接下来编写项目中redis的Service类，把redis的一些常用的get，set，exists，detete，incr，decr封装，

@Service
public class RedisService {

    @Autowired
    JedisPool jedisPool;


    public <T> T get(KeyPrefix prefix, String key,Class<T>clazz){

        Jedis jedis=null;
        try {
           jedis= jedisPool.getResource();
            String realKey = prefix.getPrefix() + key;
            String str = jedis.get(realKey);
            T t=stringToBean(str,clazz);
            return t;
        }finally {
            returnToPool(jedis);
        }
    }


    private <T> T stringToBean(String str,Class<T>clazz) {
            if (str ==null||str.length()<=0||clazz==null){
                return null;
            }
            if (clazz ==int.class||clazz == Integer.class){
                return (T)Integer.valueOf(str);
            }else if (clazz ==String.class){
                return (T)str;
            }else if (clazz ==long.class||clazz== Long.class){
                return (T)Long.valueOf(str);
            }else{
                return JSON.toJavaObject(JSON.parseObject(str),clazz);
            }
        }


    public <T> boolean set(KeyPrefix prefix,String key,T value){

        Jedis jedis=null;
        try {
         jedis= jedisPool.getResource();
         String str =beanToString(value);
         if (str == null|| str.length() <=0){
             return false;
         }
         String realKey = prefix.getPrefix() + key;
            int seconds = prefix.expireSeconds();
            if (seconds <= 0) {
                jedis.set(realKey, str);
            }else  {
                jedis.setex(realKey, seconds, str);
            }
            return true;
        }finally {
            returnToPool(jedis);
        }
    }

    private <T> String beanToString(T value) {
        if (value == null){
            return null;
        }
       Class<?>clazz= value.getClass();
        if (clazz ==int.class||clazz== Integer.class){
            return ""+value;
        }else if (clazz ==String.class){
            return (String)value;
        }else if (clazz ==long.class||clazz== Long.class){
            return ""+value;
    }else{
            return JSON.toJSONString(value);
        }


    }

    public Boolean exists(KeyPrefix prefix, String key){
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            String realPrefix = prefix.getPrefix() + key;
            return jedis.exists(realPrefix);
        }finally {
            returnToPool(jedis);
        }
    }

    public Long incr(KeyPrefix prefix, String key){
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            String realPrefix = prefix.getPrefix() + key;
            return jedis.incr(realPrefix);
        }finally {
            returnToPool(jedis);
        }
    }

    public Long decr(KeyPrefix prefix, String key){
        Jedis jedis = null;
        try {
            jedis = jedisPool.getResource();
            String realPrefix = prefix.getPrefix() + key;
            return jedis.decr(realPrefix);
        }finally {
            returnToPool(jedis);
        }
    }

    private void returnToPool(Jedis jedis){
        if (jedis !=null){
            jedis.close();
        }
    }


}