秒杀day1下

需要在Linux上安装redis，详情见下方连接
https://www.cnblogs.com/zdd-java/p/10288734.html

安装过程中可能出现一些问题，详情见下方连接
https://www.cnblogs.com/liu2-/p/6914159.html

CentOS-6.7-x86_64-bin-DVD1.iso安装见下方连接
https://blog.csdn.net/weixin_42779370/article/details/104156523

CentOS 7安装教程（图文详解）见下方连接
第19步有点问题安装出来的都是字符界面的
想要安装图形化界面可以选择Server GUI
https://blog.csdn.net/qq_44714603/article/details/88829423

测试的时候需要关闭Linux的防火墙，centos6和centos7的命令有点儿不同
或者把端口添加到防火墙里面

pom文件

  <groupId>com.imooc</groupId>
  <artifactId>miaosha</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>
  
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.8.RELEASE</version>
</parent>

  <name>miaosha_2</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-thymeleaf</artifactId>
	</dependency>
	
	<dependency>
	    <groupId>org.mybatis.spring.boot</groupId>
	    <artifactId>mybatis-spring-boot-starter</artifactId>
	    <version>1.3.1</version>
	</dependency>
	
	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
	</dependency>
	
	<dependency>
		<groupId>com.alibaba</groupId>
		<artifactId>druid</artifactId>
		<version>1.0.5</version>
	</dependency>
	
	<dependency>
	    <groupId>redis.clients</groupId>
	    <artifactId>jedis</artifactId>
	</dependency>
	
	<dependency>
	    <groupId>com.alibaba</groupId>
	    <artifactId>fastjson</artifactId>
	    <version>1.2.38</version>
	</dependency>
	
	<dependency>
	    <groupId>commons-codec</groupId>
	    <artifactId>commons-codec</artifactId>
	</dependency>
	<dependency>
	    <groupId>org.apache.commons</groupId>
	    <artifactId>commons-lang3</artifactId>
	    <version>3.6</version>
	</dependency>
	
	<dependency>
	    <groupId>commons-codec</groupId>
	    <artifactId>commons-codec</artifactId>
	</dependency>
	<dependency>
	    <groupId>org.apache.commons</groupId>
	    <artifactId>commons-lang3</artifactId>
	    <version>3.6</version>
	</dependency>
	
	<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-validation</artifactId>
    </dependency>
	
  </dependencies>
</project>

application.properties中代码

#thymeleaf
spring.thymeleaf.prefix=classpath:/templates/
spring.thymeleaf.suffix=.html
spring.thymeleaf.cache=false
spring.thymeleaf.content-type=text/html
spring.thymeleaf.enabled=true
spring.thymeleaf.encoding=UTF-8
spring.thymeleaf.mode=HTML5
# mybatis
mybatis.type-aliases-package=com.imooc.miaosha.domain//说白了就是实体对象，与数据库关联的对象
mybatis.configuration.map-underscore-to-camel-case=true
mybatis.configuration.default-fetch-size=100
mybatis.configuration.default-statement-timeout=3000
mybatis.mapperLocations = classpath:com/imooc/miaosha/dao/*.xml
# druid
spring.datasource.url=jdbc:mysql://192.168.220.128:3306/miaosha?useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&useSSL=false&
**serverTimezone=UTC**
//数据库对应的表，需要注意一下时区的问题，//这些东西都是你自己的，注意修改
spring.datasource.username=root
spring.datasource.password=root//这些东西都是你自己的，注意修改
spring.datasource.driver-class-name=com.mysql.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
#redis
redis.host=192.168.220.128
//这些东西都是你自己的，注意修改
redis.port=6379
redis.timeout=3
redis.password=123456
redis.poolMaxTotal=10
redis.poolMaxIdle=10
redis.poolMaxWait=3

在数据库中创建一个user表，就id和name俩个属性，是为了进行测试一下的

create table `user`
(
    id   int(11) not null comment '用户id',
    name varchar(100),
    primary key (id)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4 COMMENT ='用户表';

domain中代码User.java

public class User {
	private int id;
	private String name;
	get和set方法
}

Dao层UserDao代码

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

	@Insert("insert into user(id, name)values(#{id}, #{name})")
	public int insert(User user);
	
}

service中UserService代码

@Service
public class UserService {
	
	@Autowired
	UserDao userDao;
	
	public User getById(int id) {
		 return userDao.getById(id);
	}
	//事务
	@Transactional
	public boolean tx() {
		User u1= new User();
		u1.setId(2);
		u1.setName("2222");
		userDao.insert(u1);
		
		User u2= new User();
		u2.setId(1);
		u2.setName("11111");
		userDao.insert(u2);
		
		return true;
	}
	
}

controller中代码SampleController.java
该controller是来做测试的

@Controller
@RequestMapping("/demo")
public class SampleController {

	@Autowired
	UserService userService;
	
	@Autowired
	RedisService redisService;
	
    @RequestMapping("/hello")
    @ResponseBody
    public Result<String> home() {
        return Result.success("Hello，world");
    }
    
    @RequestMapping("/helloError")
    @ResponseBody
    public Result<String> error() {
        return Result.error(CodeMsg.SERVER_ERROR);
    }
    
    @RequestMapping("/themaleaf")
    public String themaleaf(Model model) {
        model.addAttribute("name", "lengleng");
        return "hello";
    }
    
    @RequestMapping("/db/get")
    @ResponseBody
    public Result<User> dbGet() {
    	User user = userService.getById(1);
        return Result.success(user);
    }
    
    
    @RequestMapping("/db/tx")
    @ResponseBody
    public Result<Boolean> dbTx() {
    	userService.tx();
        return Result.success(true);
    }
    
    @RequestMapping("/redis/get")
    @ResponseBody
    public Result<User> redisGet() {
    //redisService.get(String, Class<T> clazz);假设key是String类型的，value是T类型的
    	User  user  = redisService.get(UserKey.getById, ""+1, User.class);
        return Result.success(user);
    }
    
    @RequestMapping("/redis/set")
    @ResponseBody
    public Result<Boolean> redisSet() {
    	User user  = new User();
    	user.setId(1);
    	user.setName("1111");
    	redisService.set(UserKey.getById, ""+1, user);//UserKey:id1
        return Result.success(true);
    }    
}


@RequestMapping("/redis/get1")
    @ResponseBody
    public Result<String> redisGet1() {
        String  v1  = redisService.get1("key1", String.class);
        return Result.success(v1);
    }

    @RequestMapping("/redis/set1")
    @ResponseBody
    public Result<String> redisSet1() {
        Boolean res = redisService.set1("key2", "lengleng");
        String str = redisService.get1("key2",String.class);
        return Result.success(str);
    }

在这里插入图片描述

对通用缓存Key的封装
实现类>>抽象类>>接口（模板模式）
>>BasePrefix >>KeyPrefix
redis配置的KeyPrefix.java

public interface KeyPrefix {
		
	public int expireSeconds();//过期时间
	
	public String getPrefix();//前缀
	
}

redis配置的BasePrefix.java

public abstract class BasePrefix implements KeyPrefix{
	
	private int expireSeconds;//过期时间
	
	private String prefix;//前缀
	
	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;
	}
	
	public int expireSeconds() {//默认0代表永不过期
		return expireSeconds;
	}
	//通过类名拼接上prefix，达到不同模块的名字不一样
	public String getPrefix() {
		String className = getClass().getSimpleName();
		return className+":" + prefix;
	}
}

订单模块的Key
redis配置的OrderKey.java

public class OrderKey extends BasePrefix {

	public OrderKey(int expireSeconds, String prefix) {
		super(expireSeconds, prefix);
	}

}

redis配置的RedisConfig.java
把在application.properties的配置加载进来

@Component
//组件
@ConfigurationProperties(prefix="redis")
//让SpringBoot读取到
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
	get和set方法
}

redis配置的RedisPoolFactory.java
把JedisPool加载到Spring容器中

@Service
public class RedisPoolFactory {

	@Autowired
	RedisConfig redisConfig;
	
	@Bean
	public JedisPool JedisPoolFactory() {
		JedisPoolConfig poolConfig = new JedisPoolConfig();
		poolConfig.setMaxIdle(redisConfig.getPoolMaxIdle());
		poolConfig.setMaxTotal(redisConfig.getPoolMaxTotal());
		poolConfig.setMaxWaitMillis(redisConfig.getPoolMaxWait() * 1000);//毫秒转化位秒
		JedisPool jp = new JedisPool(poolConfig, redisConfig.getHost(), redisConfig.getPort(),
				redisConfig.getTimeout()*1000, redisConfig.getPassword(), 0);//毫秒转化位秒
		return jp;
	}
	
}

redis配置中的RedisService.java
通过该service来提供redis的服务，使用jedis来完成，jedis是通过JedisPool生成的

@Service
public class RedisService {
	
	@Autowired
	JedisPool jedisPool;
	
	/**
	 * 获取当个对象
	 * */
	public <T> T get(KeyPrefix prefix, String key,  Class<T> clazz) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();//返回的就是jedis
			 //生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			 String  str = jedis.get(realKey);
			 T t =  stringToBean(str, clazz);//把String类型的key转化为T类型
			 return t;
		 }finally {
			  returnToPool(jedis);//释放资源，返回到pool里面
		 }
	}
	
	/**
	 * 设置对象
	 * */
	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;
			 }
			//生成真正的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
	 * */
	public <T> boolean exists(KeyPrefix prefix, String key) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();
			//生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			return  jedis.exists(realKey);
		 }finally {
			  returnToPool(jedis);
		 }
	}
	
	/**
	 * 增加值
	 * */
	public <T> Long incr(KeyPrefix prefix, String key) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();
			//生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			return  jedis.incr(realKey);
		 }finally {
			  returnToPool(jedis);
		 }
	}
	
	/**
	 * 减少值
	 * */
	public <T> Long decr(KeyPrefix prefix, String key) {
		 Jedis jedis = null;
		 try {
			 jedis =  jedisPool.getResource();
			//生成真正的key
			 String realKey  = prefix.getPrefix() + key;
			return  jedis.decr(realKey);
		 }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);//将对象转化为json字符串
		}
	}

	@SuppressWarnings("unchecked")
	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);
		}
	}

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

}

redis配置中的UserKey.java

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");
}

result中的CodeMsg .java和Result.java不做过多赘述

zzzleng

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