准备数据表

create database spring_db character set utf8;
use spring_db;
create table tbl_account(id int primary key auto_increment,name varchar(35),money double
);

maven导入项目中需要的jar包

  <dependencies><dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>5.2.10.RELEASE</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version><scope>test</scope></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.16</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.20</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.2.8</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.2.10.RELEASE</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>1.3.0</version></dependency></dependencies>

创建jdbc.properties外部配置文件

jdbc.name=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/spring_db?useSSL=true&useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
jdbc.username=root
jdbc.password=123456

创建数据源的配置类JdbcConfig

package com.example.config;import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;import javax.sql.DataSource;public class JdbcConfig {@Value("${jdbc.name}")private String driver;@Value("${jdbc.url}")private String url;@Value("${jdbc.username}")private String username;@Value("${jdbc.password}")private String password;@Beanpublic DataSource dataSource(){DruidDataSource ds=new DruidDataSource();ds.setDriverClassName(driver);ds.setUrl(url);ds.setUsername(username);ds.setPassword(password);return ds;}
}

创建MyBatis配置类MyBatisConfig

package com.example.config;import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.context.annotation.Bean;import javax.sql.DataSource;public class MyBatisConfig {@Beanpublic SqlSessionFactoryBean sqlSessionFactory(DataSource dataSource){SqlSessionFactoryBean sb=new SqlSessionFactoryBean();//设置模型类的别名扫描sb.setTypeAliasesPackage("com.example.domain");//设置数据源sb.setDataSource(dataSource);return sb;}//定义bean，返回MapperScannerConfigurer对象//相当于MyBatis配置文件中的<package>扫描包路径@Beanpublic MapperScannerConfigurer mapperScannerConfigurer(){MapperScannerConfigurer msc = new MapperScannerConfigurer();msc.setBasePackage("com.example.dao");return msc;}
}

创建Spring的配置类

package com.example.config;import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.PropertySource;//表示这是一个配置类
@Configuration
//包扫描
@ComponentScan("com.example")
//加载外部配置文件
@PropertySource("classpath:jdbc.properties")
//导入数据源配置类和MyBatis配置类
@Import({JdbcConfig.class,MyBatisConfig.class})
public class SpringConfig {
}

创建实体类POJO层

package com.example.damain;public class Account {private Integer id;private String name;private Double money;//省略了getter方法和setter方法//省略了toString方法

创建数据接口层dao层

package com.example.dao;import com.example.domain.Account;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;import java.util.List;public interface AccountDao {@Insert("insert into tbl_account(name,money)values(#{name},#{money})")void save(Account account);@Delete("delete from tbl_account where id = #{id} ")void delete(Integer id);@Update("update tbl_account set name = #{name} , money = #{money} where id = #{id} ")void update(Account account);@Select("select * from tbl_account")List<Account> findAll();@Select("select * from tbl_account where id = #{id} ")Account findById(Integer id);
}

创建Service接口和实现类

package com.example.service;import com.example.domain.Account;import java.util.List;public interface AccountService {void save(Account account);void delete(Integer id);void update(Account account);List<Account> findAll();Account findById(Integer id);
}

package com.example.service.impl;import com.example.dao.AccountDao;
import com.example.domain.Account;
import com.example.service.AccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;import java.util.List;@Service
public class AccountServiceImpl implements AccountService {@Autowiredprivate AccountDao dao;@Overridepublic void save(Account account) {dao.save(account);}@Overridepublic void delete(Integer id) {dao.delete(id);}@Overridepublic void update(Account account) {dao.update(account);}@Overridepublic List<Account> findAll() {return dao.findAll();}@Overridepublic Account findById(Integer id) {return dao.findById(id);}
}

创建运行类

import com.example.config.SpringConfig;
import com.example.domain.Account;
import com.example.service.AccountService;
import org.junit.Test;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
public class Test01 {@Testpublic void test01(){AnnotationConfigApplicationContext app = new AnnotationConfigApplicationContext(SpringConfig.class);AccountService bean = app.getBean(AccountService.class);Account account = bean.findById(1);System.out.println(account);}
}