How to configure SpringBoot Mybatis files

Development environment: IDEA 2022.1.4 Mybatis

1. Overview

When BiliBili learned SprintBoot before, I typed the code according to the video. SpringBoot integrates MyBatis and writes a separate mybatis-config.xml file. Configure data connection, mapper and other information. Later, I asked a colleague who is engaged in Java and told me that the mybatis-config.xml file can actually be written to application.yml. I didn't understand it at the time. Later, as I explored it, I gradually understood it.

2. Configure mybatis-config.xml separately

2.1 Configuration content

I studied the video at that time and also wrote down a summary of the learning.

<?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核心配置文件-->
<!--顺序 properties->settings->typeAliases->typeHandlers->objectFactory->objectWrapperFactory->reflectorFactory->plugins->environments->databaseIdProvider->mappers-->
<configuration>
    <!--jdbc.properties配置文件-->
    <properties resource="jdbc.properties"></properties>
 
    <!--设置mybatis输出日志 Mybatis默认就是STDOUT_LOGGING-->
    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
 
    <!--  类型别名 默认为类名 指定这个后 mapper的xml文件指定返回值时候 可直接写类名(不区分大小写) 建议直接拷贝类名  -->
    <typeAliases>
        <package name="com.ceaning.crudp.entity"/>
    </typeAliases>
 
    <!-- 环境配置 -->
    <!-- development IDEA默认 开发环境 -->
    <!-- 可以自定义 比如定义test formal 看心情 每个SqlSessionFactory实例只能选择一种环境 这个可随时配置 -->
    <!-- test 测试环境 -->
    <!-- formal 正式环境 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>
    <!-- 映射器 每一个mapper.xml都需要在Mybatis的核心文件中注册! -->
    <!-- 注册方式1 使用xml文件 <mapper resource="com/ceaning/efmis/mapper/UserMapper.xml"/> -->
    <!-- 注册方式2 使用class文件 <mapper class="com.ceaning.efmis.mapper.UserMapper"/> -->
    <!-- 注册方式3 mapper代理方式 <package name="com.ceaning.efmis.mapper"/> -->
    <!--
        注册方式2(使用class文件)和注册方式3(使用包扫描注册)
        1.接口和他的Mapper配置文件必须同名
        2.接口和他的Mapper配置文件必须在同一个包下
    -->
    <mappers>
        <package name="com.ceaning.crudp.mapper"/>
    </mappers>
</configuration>

The content of jdbc.properties is as follows:

I write the jdbc configuration separately because I am worried that if it is deployed in WAR format in the future and the content of mybatis-config.xml is modified, there will be too much content and it is difficult to modify it. Wrong, just do a separate jdbc configuration. (Actually, I think too much)

driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
url=jdbc:sqlserver://127.0.0.1:1433;databaseName=EFMIS
username=sa
password=123qwe,.

2.2 Auxiliary class

The function of the auxiliary class is to load the configuration and create a SqlSessionFactory when the class is initially called to facilitate subsequent SQL queries.

public class MybatisUtils {
    //SqlSessionFactory 静态单例模式
    private static SqlSessionFactory sqlSessionFactory;
 
    //使用Mybatis第一步 获取SqlSessionFactory对象
    static {
        try{
            String resource="mybatis-config.xml";
            InputStream inputStream= Resources.getResourceAsStream(resource);
            sqlSessionFactory= new SqlSessionFactoryBuilder().build(inputStream);
        } catch (Exception e){
            e.printStackTrace();
        }
    }
 
    //获取SqlSession实例
    //该实例包含了面向数据库执行sql命令所需要的所有方法
    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }
}

2.3 Call operation

Here I take the login operation as an example. This way you can connect to the database for operations.

@PostMapping("/user/login")
    public Result<?> login(@RequestBody User user){
        SqlSession sqlSession= null;
        Map<String, Object> map= new HashMap<>();
        try{
            sqlSession= MybatisUtils.getSqlSession();
            UserMapper mapper= sqlSession.getMapper(UserMapper.class);
            user= mapper.login(user);
            if (user!= null){
                //生成token
                Map<String, String> tokenmap= new HashMap<>();
                tokenmap.put("loginname", user.getLoginname());
                tokenmap.put("password", user.getPassword());
                String token= JwtUtils.getToken(tokenmap);
                //返回数据
                map.put("user", user);
                map.put("token", token);
                return Result.ok(map);
            } else {
                return Result.error(CommonConstant.SYS_ERR_CODE, "用户不存在!");
            }
        } catch (Exception e){
            e.printStackTrace();
            return Result.error("异常!"+ e.getMessage());
        } finally {
            if (sqlSession!= null){
                sqlSession.close();
            }
        }
    }

3. application.yml configuration mybatis

3.1 Configuration content

Don’t worry about the extra content. The main thing is to configure the data source spring.datasource. Configure database connection information.

 Server:
  port: 8090
 
spring:
  # quartz定时任务配置
  quartz:
    # 数据库存储方式
    job-store-type: jdbc
    org:
      quartz:
        jobStore:
          class: org.springframework.scheduling.quartz.LocalDataSourceJobStore
  #配置数据源
  datasource:
    url: jdbc:sqlserver://127.0.0.1:1433;SelectMethod=cursor;databaseName=EFMIS
    username: sa
    password: 123qwe,.
    driver-class-name: com.microsoft.sqlserver.jdbc.SQLServerDriver
  #json
  jackson:
    date-format: yyyy-MM-dd HH:mm:ss
    time-zone: GMT+8
  #热部署
  devtools:
    restart:
      enabled: true
      additional-paths: src/main/java
      exclude: static/**
  jta:
    atomikos:
      properties:
        recovery:
          forget-orphaned-log-entries-delay:
mybatis:
  configuration:
    #开启驼峰映射
    map-underscore-to-camel-case: true
    #开启缓存
    cache-enabled: true
  #加载mapper.xml文件
  mapper-locations: classpath:com/ceaning/crudp/mapper/*.xml
  #别名扫描
  type-aliases-package: com.ceaning.crudp.entity
logging:
  config: classpath:logback-spring.xml

3.2 Auxiliary class

@Component
public class SpringUtils implements BeanFactoryPostProcessor {
    /**
     * Spring应用上下文环境
     */
    private static ConfigurableListableBeanFactory beanFactory;
 
 
    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory configurableListableBeanFactory) throws BeansException {
        SpringUtils.beanFactory= configurableListableBeanFactory;
    }
 
    public static <T> T getBean(String name) throws BeansException{
        name= lowerCaseInit(name);
        if(containsBean(name)){
            return (T) beanFactory.getBean(name);
        } else{
            return null;
        }
    }
 
    /**
     * 获取
     * @param cls
     * @return
     * @param <T>
     * @throws BeansException
     */
    public static <T> T getBean(Class<T> cls) throws BeansException{
        T result= (T) beanFactory.getBean(cls);
        return result;
    }
 
    /**
     * 判断 BeanFactory是否包含bean对象
     * @param name
     * @return
     */
    public static boolean containsBean(String name){
        return beanFactory.containsBean(name);
    }
 
    /**
     * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。
     * 如果与给定名字相应的bean定义没有被找到，将会抛出一个异常（NoSuchBeanDefinitionException）
     * @param name
     * @return
     * @throws NoSuchBeanDefinitionException
     */
    public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException{
        return beanFactory.isSingleton(name);
    }
 
    public static Class<?> getType(String name) throws NoSuchBeanDefinitionException{
        return beanFactory.getType(name);
    }
 
    public static String[] getAliases(String name) throws NoSuchBeanDefinitionException{
        return beanFactory.getAliases(name);
    }
 
    /**
     * 首字母小写
     * @param name
     * @return
     */
    private static String lowerCaseInit(String name){
        if(name.length()>0){
            char c= name.charAt(0);
            if(c>=65 && c<=90){
                int i= c+ 32;
                return ((char)i)+ name.substring(1);
            } else{
                return name;
            }
        } else{
            return null;
        }
    }
}

3.3 Call operation

Here we take the login operation as an example. Database connection operations can also be performed.

@PostMapping("/user/login")
    public Result<?> login(@RequestBody User user){
        Map<String, Object> map= new HashMap<>();
        try{
            UserMapper mapper= SpringUtils.getBean(UserMapper.class);
            user= mapper.login(user);
            if (user!= null){
                //生成token
                Map<String, String> tokenmap= new HashMap<>();
                tokenmap.put("loginname", user.getLoginname());
                tokenmap.put("password", user.getPassword());
                String token= JwtUtils.getToken(tokenmap);
                //返回数据
                map.put("user", user);
                map.put("token", token);
                return Result.ok(map);
            } else {
                return Result.error(CommonConstant.SYS_ERR_CODE, "用户不存在!");
            }
        } catch (Exception e){
            e.printStackTrace();
            return Result.error("异常!"+ e.getMessage());
        } 
    }

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