前言

人人都想进大厂，当然我也不例外。早在春招的时候我就有向某某某大厂投岗了不少简历，可惜了，疫情期间都是远程面试，加上那时自身也有问题，导致屡投屡败。突然也意识到自己肚子里没啥货，问个啥都是卡卡卡卡，后期下定决心好好弥补我的知识与智商，天天扎在书堆里，再加上实操，自我感觉还是不错的，有进步。

尤其是这我啃了足足58天的[Java进阶架构核心知识集]（文末有介绍，可分享），还是当初朋友面试进大厂后分享给我的。摸熟里边近30个分类的Java知识后，7月下旬鼓足勇气向抖音后端进击，123面（视频面）下来就像开挂了（幸运）。完事之后整理了一下抖音3面面经，我想大家可以参考看看。

配置一个连接在池中最小生存的时间，单位是毫秒

min-evictable-idle-time-millis: 30000

配置一个连接在池中最大生存的时间，单位是毫秒

max-evictable-idle-time-millis: 300000

validation-query: SELECT 1 FROM user

test-while-idle: true

test-on-borrow: true

test-on-return: false

是否缓存preparedStatement，也就是PSCache 官方建议MySQL下建议关闭 个人建议如果想用SQL防火墙 建议打开

pool-prepared-statements: true

max-pool-prepared-statement-per-connection-size: 20

配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall’用于防火墙

filters: stat,wall,slf4j

filter:

stat:

merge-sql: true

slow-sql-millis: 5000

second:

username: root

password: 123456

url: jdbc:mysql://192.168.50.43:3306/mybatis_second?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC

driver-class-name: com.mysql.cj.jdbc.Driver

#初始化连接池的连接数量 大小，最小，最大

initial-size: 5

min-idle: 5

max-active: 20

#配置获取连接等待超时的时间

max-wait: 60000

#配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒

time-between-eviction-runs-millis: 60000

配置一个连接在池中最小生存的时间，单位是毫秒

min-evictable-idle-time-millis: 30000

配置一个连接在池中最大生存的时间，单位是毫秒

max-evictable-idle-time-millis: 300000

validation-query: SELECT 1 FROM user

test-while-idle: true

test-on-borrow: true

test-on-return: false

是否缓存preparedStatement，也就是PSCache 官方建议MySQL下建议关闭 个人建议如果想用SQL防火墙 建议打开

pool-prepared-statements: true

max-pool-prepared-statement-per-connection-size: 20

配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall’用于防火墙

filters: stat,wall,slf4j

filter:

stat:

merge-sql: true###

slow-sql-millis: 5000

#3.基础监控配置

web-stat-filter:

enabled: true

url-pattern: /*

#设置不统计哪些URL

exclusions: “.js,.gif,.jpg,.png,.css,.ico,/druid/*”

session-stat-enable: true

session-stat-max-count: 100

stat-view-servlet:

enabled: true

url-pattern: /druid/*

reset-enable: true

#设置监控页面的登录名和密码

login-username: admin

login-password: admin

allow: 127.0.0.1

#deny: 192.168.1.100

日志配置

logging:

level:

root: INFO

com:

bolingcavalry:

druidtwosource:

mapper: debug

4. user的映射配置，请注意文件位置：

insert into user (id, name, age) values (#{id}, #{name}, #{age})

select id, name, age from user where name like concat(‘%’, #{name}, ‘%’)

delete from user where id= #{id}

5. address的映射配置：

insert into address (id, city, street) values (#{id}, #{city}, #{street})

select id, city, street from address where city like concat(‘%’, #{cityname}, ‘%’)

delete from address where id= #{id}

6. user表的实体类，注意swagger用到的注解：

package com.bolingcavalry.druidtwosource.entity;

import io.swagger.annotations.ApiModel;

import io.swagger.annotations.ApiModelProperty;

@ApiModel(description = “用户实体类”)

public class User {

@ApiModelProperty(value = “用户ID”)

private Integer id;

@ApiModelProperty(value = “用户名”, required = true)

private String name;

@ApiModelProperty(value = “用户地址”, required = false)

private Integer age;

@Override

public String toString() {

return “User{” +

“id=” + id +

“, name='” + name + ‘’’ +

“, age=” + age +

‘}’;

}

…省略get和set方法

}

7. address表的实体类：

package com.bolingcavalry.druidtwosource.entity;

import io.swagger.annotations.ApiModel;

import io.swagger.annotations.ApiModelProperty;

@ApiModel(description = “地址实体类”)

public class Address {

@ApiModelProperty(value = “地址ID”)

private Integer id;

@ApiModelProperty(value = “城市名”, required = true)

private String city;

@ApiModelProperty(value = “街道名”, required = true)

private String street;

@Override

public String toString() {

return “Address{” +

“id=” + id +

“, city='” + city + ‘’’ +

“, street='” + street + ‘’’ +

‘}’;

}

…省略get和set方法

}

8. 启动类DuridTwoSourceApplication.java，要注意的是排除掉数据源和事务的自动装配，因为后面会手动编码执行这些配置：

package com.bolingcavalry.druidtwosource;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

import org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration;

@SpringBootApplication(exclude={

DataSourceAutoConfiguration.class,

DataSourceTransactionManagerAutoConfiguration.class,

})

public class DuridTwoSourceApplication {

public static void main(String[] args) {

SpringApplication.run(DuridTwoSourceApplication.class, args);

}

}

7. swagger配置：

package com.bolingcavalry.druidtwosource;

import springfox.documentation.service.Contact;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import springfox.documentation.builders.ApiInfoBuilder;

import springfox.documentation.builders.PathSelectors;

import springfox.documentation.builders.RequestHandlerSelectors;

import springfox.documentation.service.ApiInfo;

import springfox.documentation.service.Tag;

import springfox.documentation.spi.DocumentationType;

import springfox.documentation.spring.web.plugins.Docket;

import springfox.documentation.swagger2.annotations.EnableSwagger2;

/**

• @Description: swagger配置类

• @author: willzhao E-mail: zq2599@gmail.com

• @date: 2020/8/11 7:54

*/

@Configuration

@EnableSwagger2

public class SwaggerConfig {

@Bean

public Docket createRestApi() {

return new Docket(DocumentationType.SWAGGER_2)

.apiInfo(apiInfo())

.tags(new Tag(“UserController”, “用户服务”),

new Tag(“AddressController”, “地址服务”))

.select()

// 当前包路径

.apis(RequestHandlerSelectors.basePackage(“com.bolingcavalry.druidtwosource.controller”))

.paths(PathSelectors.any())

.build();

}

//构建 api文档的详细信息函数,注意这里的注解引用的是哪个

private ApiInfo apiInfo() {

return new ApiInfoBuilder()

//页面标题

.title(“MyBatis CURD操作”)

//创建人

.contact(new Contact(“程序员欣宸”, “https://github.com/zq2599/blog_demos”, “zq2599@gmail.com”))

//版本号

.version(“1.0”)

//描述

.description(“API 描述”)

.build();

}

}

8. 数据源配置TwoDataSourceConfig.java，可见是通过ConfigurationProperties注解来确定配置信息，另外不要忘记在默认数据源上添加Primary注解：

package com.bolingcavalry.druidtwosource;

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;

import org.springframework.boot.context.properties.ConfigurationProperties;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.Primary;

import javax.sql.DataSource;

/**

• @Description: druid配置类

• @author: willzhao E-mail: zq2599@gmail.com

• @date: 2020/8/18 08:12

*/

@Configuration

public class TwoDataSourceConfig {

@Primary

@Bean(name = “firstDataSource”)

@ConfigurationProperties(“spring.datasource.druid.first”)

public DataSource first() {

return DruidDataSourceBuilder.create().build();

}

@Bean(name = “secondDataSource”)

@ConfigurationProperties(“spring.datasource.druid.second”)

public DataSource second() {

return DruidDataSourceBuilder.create().build();

}

}

9. 第一个数据源的mybatis配置类DruidConfigFirst.java，可以结合本篇的第一幅图来看，注意MapperScan注解的两个属性basePackages和sqlSessionTemplateRef是关键，它们最终决定了哪些mapper接口使用哪个数据源，另外注意要带上Primary注解：

package com.bolingcavalry.druidtwosource;

import org.apache.ibatis.session.SqlSessionFactory;

import org.mybatis.spring.SqlSessionFactoryBean;

import org.mybatis.spring.SqlSessionTemplate;

import org.mybatis.spring.annotation.MapperScan;

import org.springframework.beans.factory.annotation.Qualifier;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.Primary;

import org.springframework.core.io.support.PathMatchingResourcePatternResolver;

import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

/**

• @Description: druid配置类

• @author: willzhao E-mail: zq2599@gmail.com

• @date: 2020/8/18 08:12

*/

@Configuration

@MapperScan(basePackages = “com.bolingcavalry.druidtwosource.mapper.first”, sqlSessionTemplateRef = “firstSqlSessionTemplate”)

public class DruidConfigFirst {

@Bean(name = “firstSqlSessionFactory”)

@Primary

public SqlSessionFactory sqlSessionFactory(@Qualifier(“firstDataSource”) DataSource dataSource) throws Exception {

SqlSessionFactoryBean bean = new SqlSessionFactoryBean();

bean.setDataSource(dataSource);

bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(“classpath:mappers/first/**/*Mapper.xml”));

return bean.getObject();

}

@Bean(name = “firstTransactionManager”)

@Primary

public DataSourceTransactionManager transactionManager(@Qualifier(“firstDataSource”) DataSource dataSource) {

return new DataSourceTransactionManager(dataSource);

}

@Bean(name = “firstSqlSessionTemplate”)

@Primary

public SqlSessionTemplate sqlSessionTemplate(@Qualifier(“firstSqlSessionFactory”) SqlSessionFactory sqlSessionFactory) throws Exception {

return new SqlSessionTemplate(sqlSessionFactory);

}

}

10. 第二个数据源的mybatis配置DruidConfigSecond.java，注意不要带Primary注解：

package com.bolingcavalry.druidtwosource;

import org.apache.ibatis.session.SqlSessionFactory;

import org.mybatis.spring.SqlSessionFactoryBean;

import org.mybatis.spring.SqlSessionTemplate;

import org.mybatis.spring.annotation.MapperScan;

import org.springframework.beans.factory.annotation.Qualifier;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.core.io.support.PathMatchingResourcePatternResolver;

import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

/**

• @Description: druid配置类

• @author: willzhao E-mail: zq2599@gmail.com

• @date: 2020/8/18 08:12

*/

@Configuration

@MapperScan(basePackages = “com.bolingcavalry.druidtwosource.mapper.second”, sqlSessionTemplateRef = “secondSqlSessionTemplate”)

public class DruidConfigSecond {

@Bean(name = “secondSqlSessionFactory”)

public SqlSessionFactory sqlSessionFactory(@Qualifier(“secondDataSource”) DataSource dataSource) throws Exception {

SqlSessionFactoryBean bean = new SqlSessionFactoryBean();

bean.setDataSource(dataSource);

bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources(“classpath:mappers/second/**/*Mapper.xml”));

return bean.getObject();

}

@Bean(name = “secondTransactionManager”)

public DataSourceTransactionManager transactionManager(@Qualifier(“secondDataSource”) DataSource dataSource) {

return new DataSourceTransactionManager(dataSource);

}

@Bean(name = “secondSqlSessionTemplate”)

public SqlSessionTemplate sqlSessionTemplate(@Qualifier(“secondSqlSessionFactory”) SqlSessionFactory sqlSessionFactory) throws Exception {

return new SqlSessionTemplate(sqlSessionFactory);

}

}

11. user表的mapper接口类很简单，只有三个接口，注意package位置：

package com.bolingcavalry.druidtwosource.mapper.first;

import com.bolingcavalry.druidtwosource.entity.User;

import org.springframework.stereotype.Repository;

import java.util.List;

@Repository

public interface UserMapper {

int insertWithFields(User user);

List findByName(String name);

int delete(int id);

}

12. address表的Mapper接口类：

package com.bolingcavalry.druidtwosource.mapper.second;

import com.bolingcavalry.druidtwosource.entity.Address;

import org.springframework.stereotype.Repository;

import java.util.List;

/**

• @Description: 地址实体的接口类

• @author: willzhao E-mail: zq2599@gmail.com

• @date: 2020/8/4 8:32

*/

@Repository

public interface AddressMapper {

int insertWithFields(Address address);

List

int delete(int id);

}

13. user表的service类：

package com.bolingcavalry.druidtwosource.service;

import com.bolingcavalry.druidtwosource.entity.User;

import com.bolingcavalry.druidtwosource.mapper.first.UserMapper;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import java.util.List;

public class UserService {

@Autowired

UserMapper userMapper;

public User insertWithFields(User user) {

userMapper.insertWithFields(user);

return user;

}

public List findByName(String name) {

return userMapper.findByName(name);

}

public int delete(int id) {

return userMapper.delete(id);

}

}

14. address表的service类：

package com.bolingcavalry.druidtwosource.service;

import com.bolingcavalry.druidtwosource.entity.Address;

import com.bolingcavalry.druidtwosource.entity.User;

import com.bolingcavalry.druidtwosource.mapper.first.UserMapper;

import com.bolingcavalry.druidtwosource.mapper.second.AddressMapper;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.stereotype.Service;

import java.util.List;

@Service

public class AddressService {

@Autowired

AddressMapper addressMapper;

public Address insertWithFields(Address address) {

addressMapper.insertWithFields(address);

return address;

}

public List

return addressMapper.findByCityName(cityName);

}

public int delete(int id) {

return addressMapper.delete(id);

}

}

15. user表的controller：

package com.bolingcavalry.druidtwosource.controller;

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