秒杀系统(一)----环境搭建及集成Mybatis、Redis

1.1 环境搭建——pom文件

4.0.0

com.ustc
miaosha
1.0-SNAPSHOT

miaosha

http://www.example.com

org.springframework.boot
spring-boot-starter-parent
1.5.9.RELEASE

<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>

junit
junit
4.11
test

org.springframework.boot
spring-boot-starter-web

org.springframework.boot
spring-boot-starter-thymeleaf

org.mybatis.spring.boot
mybatis-spring-boot-starter
2.1.1

mysql
mysql-connector-java
8.0.18

com.alibaba
druid
1.1.21

redis.clients
jedis

com.alibaba
fastjson
1.2.62

org.springframework.boot
spring-boot-configuration-processor
true

commons-codec
commons-codec


org.apache.commons
commons-lang3
3.9

org.springframework.boot
spring-boot-starter-validation

org.projectlombok
lombok
1.18.10

maven-clean-plugin
3.1.0



maven-resources-plugin
3.0.2


maven-compiler-plugin
3.8.0


maven-surefire-plugin
2.22.1


maven-jar-plugin
3.0.2


maven-install-plugin
2.5.2


maven-deploy-plugin
2.8.2



maven-site-plugin
3.7.1


maven-project-info-reports-plugin
3.0.0

1.2 环境搭建——application.properties文件配置

thymeleaf

spring.thymeleaf.cache=false
spring.thymeleaf.content-type=text/html
spring.thymeleaf.enabled=true
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.mode=HTML5
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.suffix=.html

2. 测试环境

1. controller层代码：

@Controller
@RequestMapping("/demo")
public class SampleController {
@RequestMapping("/")
public String thymeleaf(Model model){
model.addAttribute("name","xc");
return "hello";
}

2. hello.html代码

3. 测试结果：
启动项目：浏览器端输入:localhost:8080/demo/
返回结果：hello:xc，则环境搭建成功。

3. 集成mybatis

1. application.properties配置：
# mybatis
mybatis.type-aliases-package=com.ustc.miaosha.domain
mybatis.configuration.map-underscore-to-camel-case=true
mybatis.configuration.default-fetch-size=100
mybatis.configuration.default-statement-timeout=3000
mybatis.mapperLocations = classpath:com/ustc/miaosha/dao/*.xml

配置druid连接池

spring.datasource.url=jdbc:mysql://localhost:3306/miaosha?useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&useSSL=false&allowPublicKeyRetrieval=true
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.filters=stat
spring.datasource.maxActive=2
spring.datasource.initialSize=1
spring.datasource.maxWait=60000
spring.datasource.minIdle=1
spring.datasource.timeBetweenEvictionRunsMillis=60000
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery=select 'x'
spring.datasource.testWhileIdle=true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn=false
spring.datasource.poolPreparedStatements=true
spring.datasource.maxOpenPreparedStatements=20

2. mysql中新建User表：
CREATE TABLE user (
id int(11) NOT NULL,
name varchar(255) DEFAULT NULL,
PRIMARY KEY (id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
3. 向user表中插入一条数据
4. 创建实体类并生成get、set方法：
@Setter
@Getter
public class User {
private int id;
private String name;
}
5. dao层接口：

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

@Insert("insert into user(id,name) values(#{id},#{name})")
int insert(User user);
}
6. Service层接口：
public interface IUserService{
User getById(int id);
boolean tx();
}

7. Service实现类：

@Service
public class UserServiceImpl implements IUserService {

@Autowired
private UserDao userDao;
public User getById(int id){
return userDao.getById(id);
}

@Transactional
public boolean tx(){
User u1 = new User();
u1.setId(2);
u1.setName("lisi");
userDao.insert(u1);

User u2 = new User();
u2.setId(1);
u2.setName("li11si");
userDao.insert(u2);

return true;
}
}

8. 创建返回值类——CodeMsg类：

@Setter
@Getter
public class CodeMsg {
private int code;
private String msg;

//通用模块
public static CodeMsg SUCCESS = new CodeMsg(0,"success");
public static CodeMsg SERVER_ERROR = new CodeMsg(500100,"服务端异常"); public CodeMsg(int code, String msg) {
this.code = code;
this.msg = msg;
}
}

创建Result类：
@Setter
@Getter
public class Result {
private int code;
private String msg;
private T data;

private Result(T data) {
this.code = 0;
this.msg = "success";
this.data = data;
}

private Result(CodeMsg codeMsg) {
if (codeMsg == null){
return;
}
this.code = codeMsg.getCode();
this.msg = codeMsg.getMsg();
}

/**
* 成功得时候调用
* @param data
* @param
* @return
*/
public static Result success(T data){
return new Result(data);
}

/**
* 失败得时候调用
* @param codeMsg
* @param
* @return
*/
public static Result error(CodeMsg codeMsg){
return new Result(codeMsg);
}

9. controller层：
@Controller
@RequestMapping("/demo")
public class SampleController {

@Autowired
private UserService userService;

@RequestMapping("/db/get")
@ResponseBody
public Result dbGet(){
User user = userService.getById(1);
return Result.success(user);
}

@RequestMapping("/db/tx")
@ResponseBody
public Result dbTx(){
userService.tx();
return Result.success(true);
}
}

10. 测试：启动项目，输入localhost:8080/demo/db/get 能够查询到数据，输入localhost:8080/demo/db/get插入一条数据，说明myBatis集成成功。

4. 集成Redis

1. application.properties配置：
#redis
redis.host=192.168.124.128
redis.port=6379
redis.timeout=3
redis.password=123456
redis.poolMaxTotal=10
redis.poolMaxIdle=10
redis.poolMaxWait=3

2. 创建配置文件对应的实体类读取配置文件：

@Component
@ConfigurationProperties(prefix = "redis")
@Setter
@Getter
public class RedisConfig {
private String host;
private int port;
private int timeout; //秒
private String password;
private int poolMaxTotal;
private int poolMaxIdle;
private int poolMaxWait;//秒
}

3. 创建RedisPool连接工厂

@Service
public class RedisPoolFactory {
@Autowired
RedisConfig redisConfig;

@Bean
public JedisPool jedisPoolFactory(){
System.out.println(redisConfig.toString());
JedisPoolConfig poolConfig = new JedisPoolConfig();
poolConfig.setMaxIdle(redisConfig.getPoolMaxIdle());
poolConfig.setMaxTotal(redisConfig.getPoolMaxTotal());
poolConfig.setMaxWaitMillis(redisConfig.getPoolMaxWait() * 1000);
JedisPool jp = new JedisPool(poolConfig,redisConfig.getHost(),redisConfig.getPort(),redisConfig.getTimeout()*1000,redisConfig.getPassword(),0);
return jp;
}
}

4. 创建RedisService

@Service
public class RedisService {

@Autowired
JedisPool jedisPool;

/**
* 查询key
* @param prefix
* @param key
* @param clazz
* @param
* @return
*/
public T get(KeyPrefix prefix, String key, Class clazz){
Jedis jedis = null;
try {
jedis = jedisPool.getResource();
//生成真正得Key;
String realKey = prefix.getPrefix() + key;
String str = jedis.get(realKey);
T t = stringToBean(str,clazz);
return t;
}finally {
returnToPool(jedis);
}
}

/**
* 存入key
* @param prefix
* @param key
* @param value
* @param
* @return
*/
public 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;
}
//生成真正得Key;
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);
}
}

/**
* 判断key是否存在
* @param prefix
* @param key
* @param
* @return
*/
public Boolean exist(KeyPrefix prefix, String key){

Jedis jedis = null;
try {
jedis = jedisPool.getResource();
//生成真正得Key;
String realKey = prefix.getPrefix() + key;
return jedis.exists(realKey);
}finally {
returnToPool(jedis);
}
}

/**
* key值自增
* @param prefix
* @param key
* @param
* @return
*/
public Long incr(KeyPrefix prefix, String key){

Jedis jedis = null;
try {
jedis = jedisPool.getResource();
//生成真正得Key;
String realKey = prefix.getPrefix() + key;
return jedis.incr(realKey);
}finally {
returnToPool(jedis);
}
}

/**
* key值自减
* @param prefix
* @param key
* @param
* @return
*/
public Long decr(KeyPrefix prefix, String key){

Jedis jedis = null;
try {
jedis = jedisPool.getResource();
//生成真正得Key;
String realKey = prefix.getPrefix() + key;
return jedis.decr(realKey);
}finally {
returnToPool(jedis);
}
}

/**
* 实体类转换成String类型
* @param value
* @param
* @return
*/
private 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);
}
}

/**
* String类型转换成实体类
* @param str
* @param clazz
* @param
* @return
*/
private T stringToBean(String str, Class clazz) {
if (str == null || str.length() <= 0){
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);
}
}

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

}

5. 测试：
创建KeyPreFifx接口

public interface KeyPrefix {
int expireSeconds();
String getPrefix();
}

创建抽象类BasePrefix

@Setter
@Getter
public abstract class BasePrefix implements KeyPrefix {

private int expireSeconds; //设置过期时间
private String prefix;

public BasePrefix(String prefix){ //0代表永不过期
this(0,prefix);
}

public BasePrefix(int expireSeconds, String prefix) {
this.expireSeconds = expireSeconds;
this.prefix = prefix;
}
}

创建UserKey继承抽象类BasePrefix

public class UserKey extends BasePrefix {
private UserKey(String prefix) {
super(prefix);
}

public static UserKey getById = new UserKey("id");
public static UserKey getByName = new UserKey("name");
}

Controller层添加方法：
@RequestMapping("/redis/get")
@ResponseBody
public Result redisGet(){
User user = redisService.get(UserKey.getById,""+1,User.class);
return Result.success(user);
}

@RequestMapping("/redis/set")
@ResponseBody
public Result redisSet(){
User user = new User(1,"1111111");
Boolean v1 = redisService.set(UserKey.getById,""+1,user);
return Result.success(v1);
}

启动项目：输入localhost:8080/demo/redis/set插入一条数据，在输入localhost:8080/demo/redis/get查询出刚才插入的数据。

至此，Redis集成完成。