以下是详细的过程，可用于复习，或者不看视频的使用，最后有自己遇见的报错的解决方案
Java 版本 ： JDK 1.8
Maven 版本 ： maven 3.6.1
开发工具 ： IDEA
项目使用 maven 创建方式，推荐使用 IDEA 直接创建 maven 项目
可以使用 maven 命令创建 web 骨架(maven 需要配置到环境变量)
mvn archetype:create -DgroupId=com.node.seckill -DartifactID=seckkill -DarchetypeArtifactId=maven-archetype-web直接使用 IDEA 创建，添加 web 组件
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>seckill_ssm</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<!--使用 junit-->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13</version>
<scope>test</scope>
</dependency>
<!--导入日志依赖-->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.30</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-core</artifactId>
<version>1.2.3</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>1.2.3</version>
</dependency>
<!--数据库依赖-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>
<!--c3po -->
<dependency>
<groupId>c3p0</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.1.2</version>
</dependency>
<!--Dao 层 mybatis-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.4</version>
</dependency>
<!--mybatis-spring 整合-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.4</version>
</dependency>
<!--service： web 依赖-->
<dependency>
<groupId>taglibs</groupId>
<artifactId>standard</artifactId>
<version>1.1.2</version>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.10.3</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.1</version>
</dependency>
<!--spring 依赖-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.5.RELEASE</version>
</dependency>
<!--lombok 依赖-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.10</version>
<scope>provided</scope>
</dependency>
</dependencies>
<!--设置 Maven 过滤资源mysl-->
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
</build>
</project>秒杀业务主要是在商品增加调整库存，用户对库存进行购买秒杀的行为
主要核心是对库存进行处理
这里使用的是 MySQL（事务+行锁） ，现在 redis 也能很好的支持事务，尤其适合在高并发情况下完成。
-- 数据库初始话脚本
-- 创建数据库
CREATE DATABASE seckill;
-- 使用数据库
use seckill;
-- 创建秒杀库存表
CREATE TABLE seckill(
`seckill_id` bigint NOT NULL AUTO_INCREMENT COMMENT '商品库存id',
`name` varchar(120) NOT NULL COMMENT '商品名称',
`number` int NOT NULL COMMENT '库存数量',
`start_time` datetime NOT NULL COMMENT '秒杀开启时间',
`end_time` datetime NOT NULL COMMENT '秒杀关闭时间',
`create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
PRIMARY KEY (seckill_id),
KEY idx_start_time(start_time),
KEY idx_end_time(end_time),
KEY idx_create_time(create_time)
)ENGINE=InnoDB AUTO_INCREMENT=1000 DEFAULT CHARSET=utf8 COMMENT='秒杀库存表';
-- 初始化数据
INSERT INTO
seckill (name, number, start_time, end_time)
values
('10000 元秒杀 MacBook Pro', 100, '2020-4-12 00:00:00', '2020-4-12 00:00:00'),
('1000 元秒杀 ipad Pro', 200, '2020-4-12 00:00:00', '2020-4-12 00:00:00'),
('1000 元秒杀 小米10', 300, '2020-4-12 00:00:00', '2020-4-12 00:00:00'),
('1000 元秒杀 红米 k30', 100, '2020-4-12 00:00:00', '2020-4-12 00:00:00');
-- 秒杀成功表
CREATE TABLE success_killed(
`seckill_id` bigint NOT NULL COMMENT '秒杀商品id',
`user_phone` bigint NOT NULL COMMENT '用户手机号',
`state` tinyint NOT NULL DEFAULT -1 COMMENT '状态标识位：-1 无效 0 成功 1 已付款',
`create_time` timestamp NOT NULL COMMENT='创建时间',
PRIMARY KEY ("seckill_id","user_phone"),
KEY idx_create_time(create_time)
)ENGINE=InnoDB DEFAULT ChARSET=utf8 COMMENT='秒杀明细表';注意点
- 数据库使用时需要先创建
数据库 seckill, 数据库创建类型编码方式需要选择 utf8
使用 Mybatis 完成对 Dao 层数据映射（因为使用 mybatis dao 层包名可以为 mapper，效果一样）
3、配置对应的 xxxMapper.xml 配置文件
SeckillMapper.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="org.seckill.mapper.SeckillMapper">
<!-- 目的：为dao接口方法提供sql语句配置 -->
<update id="reduceNumber">
<!-- 具体的sql -->
UPDATE seckill
SET number = number - 1
WHERE
seckill_id = #{seckillId}
AND start_time <![CDATA[ <= ]]> #{killTime}
AND end_time >= #{killTime}
AND number > 0
</update>
<select id="queryById" resultType="Seckill" parameterType="long">
SELECT
seckill_id,
NAME,
number,
start_time,
end_time,
create_time
FROM
seckill
WHERE
seckill_id = #{seckillId}
</select>
<select id="queryAll" resultType="Seckill">
SELECT
seckill_id,
NAME,
number,
start_time,
end_time,
create_time
FROM
seckill
ORDER BY
create_time DESC
LIMIT #{offset},
#{limit}
</select>
</mapper>SuccessKilledMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="org.seckill.mapper.SuccessKilledMapper">
<!--如果出现主键冲突，报错-->
<insert id="insertSuccessKilled">
insert ignore into success_killed (seckill_id, user_phone,state)
values (#{seckillId}, #{userPhone},0)
</insert>
<select id="queryByIdWithSeckill" resultType="SuccessKilled">
select
sk.seckill_id,
sk.user_phone,
sk.create_time,
sk.state,
s.seckill_id "seckill.seckill_id",
s.name "seckill.name",
s.number "seckill.number",
s.start_time "seckill.start_time",
s.end_time "seckill.end_time",
s.create_time "seckill.create_time"
from success_killed sk
inner join seckill s on sk.seckill_id = s.seckill_id
where sk.seckill_id = #{seckillId} and sk.user_phone = #{userPhone}
</select>
</mapper>4、配置 mybatis
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!-- 配置全局属性 -->
<settings>
<!-- 使用jdbc的getGeneratedKeys获取数据库自增主键值 -->
<setting name="useGeneratedKeys" value="true" />
<!-- 使用列别名替换列名 默认:true -->
<setting name="useColumnLabel" value="true" />
<!-- 开启驼峰命名转换:Table{create_time} -> Entity{createTime} -->
<setting name="mapUnderscoreToCamelCase" value="true" />
</settings>
</configuration>5、配置 JDCB 配置
在 resource 文件夹下建立 jdbc 的配置文件 jdbc.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/seckill?useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=root #根据个人数据库情况配置6、整合 spring
在 resource 文件夹下建立 spring 文件夹存放和 spring 配置有关的文件，建立 spring-dao.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 配置整合mybatis过程 -->
<!-- 1.配置数据库相关参数properties的属性：${url} -->
<context:property-placeholder location="classpath:jdbc.properties" />
<!-- 2.数据库连接池 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<!-- 配置连接池属性 -->
<property name="driverClass" value="${jdbc.driver}" />
<property name="jdbcUrl" value="${jdbc.url}" />
<property name="user" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<!-- c3p0连接池的私有属性 -->
<property name="maxPoolSize" value="30" />
<property name="minPoolSize" value="10" />
<!-- 关闭连接后不自动commit -->
<property name="autoCommitOnClose" value="false" />
<!-- 获取连接超时时间 -->
<property name="checkoutTimeout" value="10000" />
<!-- 当获取连接失败重试次数 -->
<property name="acquireRetryAttempts" value="2" />
</bean>
<!-- 3.配置SqlSessionFactory对象 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 注入数据库连接池 -->
<property name="dataSource" ref="dataSource" />
<!-- 配置MyBaties全局配置文件:mybatis-config.xml -->
<property name="configLocation" value="classpath:mybatis-config.xml" />
<!-- 扫描entity包 使用别名 -->
<property name="typeAliasesPackage" value="org.seckill.pojo.entity" />
<!-- 扫描sql配置文件:mapper需要的xml文件 -->
<property name="mapperLocations" value="classpath:mybatis/mapper/*.xml" />
</bean>
<!-- 4.配置扫描Dao接口包，动态实现Dao接口，注入到soring容器中 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 注入sqlSessionFactory -->
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
<!-- 给出需要扫描Dao接口包 -->
<property name="basePackage" value="org.seckill.mapper" />
</bean>
</beans>7、测试
在 mapper 接口上使用快捷键 ctrl+shift+t快捷创建测试文件
SeckillMapperTest （需要导入 spring-test 依赖否则无法使用）
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"classpath:spring/spring-dao.xml"})
public class SeckillMapperTest {
@Autowired
private SeckillMapper seckillMapper;
@Test
public void queryById() {
long id = 1002;
Seckill seckill = seckillMapper.queryById(id);
System.out.println(seckill.getName());
System.out.println(seckill);
}
@Test
public void queryAll() {
List<Seckill> seckills = seckillMapper.queryAll(0, 100);
System.out.println(seckills);
}
@Test
public void reduceNumber() {
Date killTime = new Date();
int updateCount = seckillMapper.reduceNumber(1000L, killTime);
System.out.println(updateCount);
}
}SuccessKilledMapperTest 类
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({"classpath:spring/spring-dao.xml"})
public class SuccessKilledMapperTest {
@Resource
private SuccessKilledMapper successKilledMapper;
@Test
public void insertSuccessKilled() {
long id = 1001L;
long phone = 182222213L;
int i = successKilledMapper.insertSuccessKilled(id, phone);
System.out.println(i);
}
@Test
public void queryByIdWithSeckill() {
long id = 1001L;
long phone = 182222213L;
SuccessKilled successKilled = successKilledMapper.queryByIdWithSeckill(id,phone);
System.out.println("==========");
System.out.println("successKilled "+successKilled);
System.out.println(successKilled.getSeckill());
System.out.println(successKilled.getSeckill().getNumber());
}
}设计 service 业务接口需要站在 使用者 角度
接口设计三个反面：方法定义粒度、参数、返回类型
接口设计前准备，需要设计需要抛出的异常
public class SeckillException extends RuntimeException {
public SeckillException() {
}
public SeckillException(String message) {
super(message);
}
public SeckillException(String message, Throwable cause) {
super(message, cause);
}
}
// 秒杀关闭异常
public class SeckillCloseException extends SeckillException {
public SeckillCloseException() {
}
public SeckillCloseException(String message) {
super(message);
}
}
//重复秒杀异常(运行期异常)
public class RepeatKillException extends SeckillException{
public RepeatKillException(String message) {
super(message);
}
public RepeatKillException(String message, Throwable cause) {
super(message, cause);
}
}返回状态
public enum SeckillStatEnum {
SUCCESS(1,"秒杀成功"),
END(0,"秒杀结束"),
REPEAT_KILL(-1, "重复秒杀"),
INNER_ERROR(-2, "系统异常"),
DATA_REWRITE(-3,"数据篡改");
private int state;
private String stateInfo;
SeckillStatEnum(int state, String stateInfo) {
this.state = state;
this.stateInfo = stateInfo;
}
public int getState() {
return state;
}
public String getStateInfo() {
return stateInfo;
}
public static SeckillStatEnum stateOf(int index){
for (SeckillStatEnum state : values()){
if (state.getState() == index){
return state;
}
}
return null;
}
}Dto
Exposer
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Exposer {
// 是否开启秒杀
private boolean exposed;
// 对接口加密
private String md5;
//id
private long seckillId;
// 系统当前时间(毫秒)
private long now;
// 开启时间
private long start;
//结束时间
private long end;
public Exposer(boolean exposed, String md5, long seckillId) {
this.exposed = exposed;
this.md5 = md5;
this.seckillId = seckillId;
}
public Exposer(boolean exposed, long seckillId, long now, long start, long end) {
this.exposed = exposed;
this.seckillId = seckillId;
this.now = now;
this.start = start;
this.end = end;
}
public Exposer(boolean exposed, long seckillId) {
this.exposed = exposed;
this.seckillId = seckillId;
}
}SeckillExecution
@Data
public class SeckillExecution {
private long seckillId;
// 秒杀状态
private int state;
// 秒杀返回信息
private String stateInfo;
// 秒杀成功对象
private SuccessKilled successKilled;
public SeckillExecution(long seckillId, SeckillStatEnum statEnum, SuccessKilled successKilled) {
this.seckillId = seckillId;
this.state = statEnum.getState();
this.stateInfo = statEnum.getStateInfo();
this.successKilled = successKilled;
}
// 返回失败的构造函数
public SeckillExecution(long seckillId, SeckillStatEnum statEnum) {
this.seckillId = seckillId;
this.state = statEnum.getState();
this.stateInfo = statEnum.getStateInfo();
}
}1、SeckillService 秒杀接口设计
public interface SeckillService {
/**
* 查询所有秒杀记录
* @return
*/
List<Seckill> getSeckillList();
/**
* 查询单个秒杀记录
* @param seckillId
* @return
*/
Seckill getById(long seckillId);
/**
* 秒杀开启时输出秒杀接口地址，否则输出系统时间和秒杀时间
* 不到时间不放出秒杀地址
* @param seckillId
*/
Exposer exportSeckillUrl(long seckillId);
/**
* 执行秒杀
* @param seckillId
* @param userPhone
* @param md5
*/
SeckillExecution executeSeckill(long seckillId, long userPhone, String md5)
throws SeckillException, RepeatKillException, SeckillCloseException;
}对应的实现类
@Service
public class SeckillServiceImpl implements SeckillService {
private Logger logger = LoggerFactory.getLogger(this.getClass());
@Autowired
private SeckillMapper seckillMapper;
@Autowired
private SuccessKilledMapper successKilledMapper;
private final String slat = "1dsaw43dsf4r4fdsf2r";
public List<Seckill> getSeckillList() {
return seckillMapper.queryAll(0,4);
}
public Seckill getById(long seckillId) {
return seckillMapper.queryById(seckillId);
}
public Exposer exportSeckillUrl(long seckillId) {
Seckill seckill = seckillMapper.queryById(seckillId);
if (seckill == null){
return new Exposer(false,seckillId);
}
Date startTime = seckill.getStartTime();
Date endTime = seckill.getEndTime();
Date nowTime = new Date();
System.out.println("now====>"+nowTime.getTime());
System.out.println("start====>"+startTime.getTime());
System.out.println("end====>"+endTime.getTime());
if (nowTime.getTime() < startTime.getTime()
|| nowTime.getTime() > endTime.getTime()){
return new Exposer(false, seckillId, nowTime.getTime(), startTime.getTime(),endTime.getTime());
}
// 转化特定字符串过程，不可逆
String md5 = getMD5(seckillId); //TODO
return new Exposer(true, md5, seckillId);
}
private String getMD5(long seckillId){
String base = seckillId + "/" + slat;
String md5 = DigestUtils.md5DigestAsHex(base.getBytes());
return md5;
}
@Transactional
/**
* 使用租界控制事务方法：
* 1：明确标注书屋的编程风格
* 2：保证事务方法的执行时间尽可能短，不穿插其他网络调用
* 3：不是所有的方法都需要事务
*/
public SeckillExecution executeSeckill(long seckillId, long userPhone, String md5)
throws SeckillException, RepeatKillException, SeckillCloseException {
if (md5 == null || !md5.equals(getMD5(seckillId))){
throw new SeckillException("seckill data rewrite");
}
// 减少库存
Date nowTime = new Date();
try {
int updateCount = seckillMapper.reduceNumber(seckillId, nowTime);
if (updateCount <= 0){
// 没有更新记录
throw new SeckillCloseException("seckill is closed");
}else {
// 减少库存成功，记录购买行为
int insertCount = successKilledMapper.insertSuccessKilled(seckillId, userPhone);
if (insertCount <= 0){
// 重复秒杀
throw new RepeatKillException("seckill repeat");
} else {
SuccessKilled successKilled = successKilledMapper.queryByIdWithSeckill(seckillId, userPhone);
return new SeckillExecution(seckillId, SeckillStatEnum.SUCCESS,successKilled);
}
}
}catch (SeckillCloseException e1){
throw e1;
}catch (RepeatKillException e2){
throw e2;
}catch (Exception e){
logger.error(e.getMessage(), e);
// 编译器异常改成运行期异常，方便事务回滚
throw new SeckillException("seckill inner error");
}
}
}2、sping 整合配置文件
创建 spring-service.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<!--配置扫描包,包括子包-->
<context:component-scan base-package="org.seckill.service"/>
<!--配置事务管理器-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<!--注入 数据库 连接池-->
<property name="dataSource" ref="dataSource"/>
</bean>
<!--配置基于注解的声明式书屋，默认通过注解方式管理-->
<tx:annotation-driven transaction-manager="transactionManager"/>
</beans>
3、配置 logback.xml
logback 官网：http://logback.qos.ch/manual/configuration.html
<?xml version="1.0" encoding="UTF-8" ?>
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<!-- encoders are assigned the type
ch.qos.logback.classic.encoder.PatternLayoutEncoder by default -->
<encoder>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
</encoder>
</appender>
<root level="debug">
<appender-ref ref="STDOUT" />
</root>
</configuration>4、测试，这里测试需要调整数据库中的秒杀开始和结束时间
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({
"classpath:spring/spring-dao.xml",
"classpath:spring/spring-service.xml"})
public class SeckillServiceTest {
private final Logger logger = LoggerFactory.getLogger(this.getClass());
@Autowired
private SeckillService seckillService;
@Test
public void getSeckillList() {
List<Seckill> list = seckillService.getSeckillList();
logger.info("list={}",list);
}
@Test
public void getById() {
long id = 1000;
Seckill seckill = seckillService.getById(id);
logger.info("seckill={}",seckill);
}
@Test
public void exportSeckillUrl() {
long id = 1000;
Exposer exposer = seckillService.exportSeckillUrl(id);
logger.info("exposer={}",exposer);
//exposer=Exposer(exposed=true, md5=bb9b50d6d0d6d4959dfae710151e5f33, seckillId=1000, now=0, start=0, end=0)
}
@Test
public void executeSeckill() {
long id = 1000;
long phone = 18226568383L ;
String md5 ="bb9b50d6d0d6d4959dfae710151e5f33";
SeckillExecution execution = seckillService.executeSeckill(id, phone, md5);
logger.info("execution={}",execution);
}
@Test
public void testSeckillLogic(){
long id = 1002;
Exposer exposer = seckillService.exportSeckillUrl(id);
if (exposer.isExposed()){
logger.info("exposer={}",exposer);
long phone = 18226568383L ;
String md5 =exposer.getMd5();
try {
SeckillExecution execution = seckillService.executeSeckill(id, phone, md5);
logger.info("execution={}",execution);
} catch (RepeatKillException e){
logger.error(e.getMessage());
} catch (SeckillException e){
logger.error(e.getMessage());
}
}else {
logger.warn("esposer={}",exposer);
}
}
}前端页面流程
秒杀流程逻辑
- URL合理的表达方式
- 资源状态和状态转移
restful 规范
-
/模块/资源/{标识}/集合/...
-
GET 查询
-
POST 修改删除
-
PUT 修改
-
DELETE 删除
秒杀 API 的URL 设计
Sping MVC 在秒杀系统中的运行流程
HTTP 请求地址映射原理
web 层的实现方式是先整合 springMVC
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
<!--配置 springMVC-->
<!--1：配置springMVC注解配置-->
<!-- 简化配置：
（1）自动注册 DefaultAnnotationHandlerMapping，AnnotationMethodHandlerAdapter
（2）提供一系列：数据绑定，数字和日期的 format ，@NumberFormat，@DataTimeFormat，
xml，json 默认读写支持
-->
<mvc:annotation-driven/>
<!-- 2：servlet-mapping 映射路径 “/”-->
<!-- （1）静态资源默认处理：js，gif，png
（2）允许使用“/”做整体映射-->
<mvc:default-servlet-handler/>
<!--3:配置jsp 显示 ViewResolver-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!--4：扫描 web 相关的bean-->
<context:component-scan base-package="org.seckill.controller"/>
</beans>然后通过 bootstrap 编写两个 list 和 detail 两个 jsp 页面。
对传输过来的数据进行处理展示，秒杀逻辑通过 js 做一些判断，js 模块化的方式交互。
秒杀地址接口
秒杀操作优化
成本分析
使用 MySQL 的瓶颈分析 (但 update 4w次qps，正常 500次 qps)
MySQL 中解决问题
优化总结
- 前端控制：暴露接口，防止按钮重复
- 动静数据分离：CDN缓存，后端缓存
- 事务竞争优化：减少事务锁时间（ACID）
原本
降低 update 是 rowLock 的时间，缩短了一倍网络延迟和GC
代码调整为：
public SeckillExecution executeSeckill(long seckillId, long userPhone, String md5)
throws SeckillException, RepeatKillException, SeckillCloseException {
if (md5 == null || !md5.equals(getMD5(seckillId))){
throw new SeckillException("seckill data rewrite");
}
// 减少库存
Date nowTime = new Date();
try {
// 减少库存成功，记录购买行为
int insertCount = successKilledMapper.insertSuccessKilled(seckillId, userPhone);
if (insertCount <= 0){
// 重复秒杀
throw new RepeatKillException("seckill repeat");
} else {
int updateCount = seckillMapper.reduceNumber(seckillId, nowTime);
if (updateCount <= 0){
// 没有更新记录
throw new SeckillCloseException("seckill is closed");
} else {
SuccessKilled successKilled = successKilledMapper.queryByIdWithSeckill(seckillId, userPhone);
return new SeckillExecution(seckillId, SeckillStateEnum.SUCCESS,successKilled);
}
}
}catch (SeckillCloseException e1){
throw e1;
}catch (RepeatKillException e2){
throw e2;
}catch (Exception e){
logger.error(e.getMessage(), e);
// 编译器异常改成运行期异常，方便事务回滚
throw new SeckillException("seckill inner error");
}
}存储过程的目的是让update insert 能够在本地进行事务缩短了时间
配置好 tomcat 访问 index 可以访问，访问 controller 中的请求出现 500
后台报错信息：org.apache.catalina.core.StandardWrapperValve.invoke Allocate exception for servlet [seckill-dispatcher]
出现原因 target/WEB-INF 没有 lib
在IDEA中 artifacts 中选中项目添加 lib 目录，并添加所有的依赖，后面如果还出现此类 dispatcher 层面的报错仍然需要这样修改
配置完成后重新启动查看测试
设置Cookie 时出现黑色屏幕
无法点击秒杀号码输入，这是因为 bootstrap 版本问题，修改版本为 3.3.0 即可
