# seckill

**Repository Path**: zlray/seckill

## Basic Information

- **Project Name**: seckill
- **Description**: 简单的秒杀系统
- **Primary Language**: Java
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2017-12-10
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

redis并没有实现内部序列化操作：get->byte[] ==>反序列化 ->Object(Seckill类型)
采用自定义序列化：protostuff ： pojo
```
<!-- 序列化插件：protostuff依赖 -->
		<dependency>
			<groupId>com.dyuproject.protostuff</groupId>
			<artifactId>protostuff-core</artifactId>
			<version>1.0.8</version>
		</dependency>
		<dependency>
			<groupId>com.dyuproject.protostuff</groupId>
			<artifactId>protostuff-runtime</artifactId>
			<version>1.0.8</version>
		</dependency>
```
	
```
 byte[] bytes = jedis.get(key.getBytes());
                // 缓存中获取到
                if(bytes != null){
                    Seckill seckill = schema.newMessage();//创建空的对象
                    ProtostuffIOUtil.mergeFrom(bytes,seckill,schema);
                    // seckill 被反序列
                    return seckill;
```
 
   ```
 byte[] bytes = ProtostuffIOUtil.toByteArray(seckill,schema,
                    LinkedBuffer.allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE));
```
双重检测取缓存
```
private  volatile static  Seckill seckill;
.......
        seckill = redisDao.getSeckill(seckillId);
        if(null == seckill){
        	synchronized(this) {
        		seckill = redisDao.getSeckill(seckillId);
        		if(null == seckill) {
        			//2：访问数据库,表示没有从缓存中取到数据；
        			seckill = seckillDao.queryById(seckillId);
        			if(null == seckill){
        				return new Exposer(false,seckillId);
        			}else {
        				//3：放入redis
        				redisDao.putSeckill(seckill);
        			}
        		}
        	}
        }
```  
![红色部分是可优化部分](https://gitee.com/uploads/images/2018/0104/093603_bed2ea8c_1370933.png "11.png") ![输入图片说明](https://gitee.com/uploads/images/2018/0104/093856_968d8b69_1370933.png "123.png")![输入图片说明](https://gitee.com/uploads/images/2018/0104/093826_c78d1f4c_1370933.png "13.png")![输入图片说明](https://gitee.com/uploads/images/2018/0104/093950_2d3177b4_1370933.png "15.png")![输入图片说明](https://gitee.com/uploads/images/2018/0104/093737_3004b56f_1370933.png "14.png")