标签：ace   文件   manager   数据   data   mapper   ram   def   .data   

配置

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-dbcp2</artifactId>
            <version>2.2.0</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>6.0.6</version>
        </dependency>

application.yml

spring:
    datasource:
      driver-class-name: com.mysql.cj.jdbc.Driver
      dbcp2:
        driver-class-name: com.mysql.cj.jdbc.Driver
        password: ***
        url: jdbc:mysql://127.0.0.1:3306/pzx?serverTimezone=UTC&characterEncoding=utf8&useUnicode=true&useSSL=false
        username: app
        max-total: 1024

Config文件

@Component
@ConfigurationProperties("spring.datasource.dbcp2")
class MySqlConfig {

    var driverClassName = "com.mysql.jdbc.Driver"
    var username = ""
    var password = ""
    var url = ""
    var maxTotal = 0;
    var maxIdel = 0;
    var maxWaitMillis = 0L

    @Bean
    fun dataSource(): BasicDataSource {
        println("BasicDataSource inited: ${url}")
        val dataSource = BasicDataSource()
        dataSource.driverClassName = driverClassName
        dataSource.url = url
        dataSource.username = username
        dataSource.password = password
        dataSource.maxTotal = maxTotal
        dataSource.maxIdle = maxIdel
        dataSource.maxWaitMillis = maxWaitMillis
        dataSource.setValidationQuery("SELECT 1")
        dataSource.testOnBorrow = true
        return dataSource
    }

}


@Component
@AutoConfigureAfter(MySqlConfig::class)
class MyBatisSessionConfig {
    @Bean
    fun mapperScannerConfigurer(): MapperScannerConfigurer {
        val mapperScannerConfigurer = MapperScannerConfigurer()
        //获取之前注入的beanName为sqlSessionFactory的对象
        mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory")
        //指定xml配置文件的路径
        mapperScannerConfigurer.setBasePackage("pzx.db.mybatis.mapper")
        return mapperScannerConfigurer
    }
}


@Configuration
//加上这个注解，使得支持事务
@EnableTransactionManagement
class MyBatisConfig : TransactionManagementConfigurer {

    @Autowired
    private var dataSource: DataSource? = null

    override fun annotationDrivenTransactionManager(): PlatformTransactionManager {
        return DataSourceTransactionManager(dataSource!!)
    }

    @Bean(name = arrayOf("sqlSessionFactory"))
    fun sqlSessionFactoryBean(): SqlSessionFactory? {
        val bean = SqlSessionFactoryBean()
        bean.setDataSource(dataSource)

        try {
            return bean.`object`
        } catch (e: Exception) {
            e.printStackTrace()
            throw RuntimeException(e)
        }

    }

    @Bean
    fun sqlSessionTemplate(sqlSessionFactory: SqlSessionFactory): SqlSessionTemplate {
        return SqlSessionTemplate(sqlSessionFactory)
    }
}

Mapper文件

@Mapper
interface CityMapper {
    @Select("select * from s_city where code = #{code}")
    @Results(value = arrayOf(Result(column = "password", property = "password")))
    fun findByCode(@Param("code") code: String): SysCity?
}

调用

    @Autowired
    lateinit var ds : CityMapper

    @GetMapping("/testMySql")
    fun testMySql(request: HttpServletRequest): String {
        var e = ds.findByCode("110")

        return request.UserId;
    }

源码跟踪

依次执行：

• MapperMethod.execute -> sqlSession.selectOne
• SqlSessionTemplate.selectOne
• DefaultSqlSession.selectOne
• DefaultSqlSession.selectList ->
  MappedStatement ms = configuration.getMappedStatement(statement);
  return executor.query(ms, wrapCollection(parameter), rowBounds, Executor.NO_RESULT_HANDLER);

到这里， Configuration 出现了。

• CachingExecutor.query ->
  createCacheKey
  query

出现在Sql及CacheKey： 383339099:1114119213:pzx.db.mybatis.mapper.CityMapper.findByCode:0:2147483647:select * from s_city where code = ?:110:SqlSessionFactoryBean
分为以下部分： hashcode:checksum:各个部分。 前面的 hashcode:checksum 可以表示唯一了， 添加后面的部分， 是为了描述元数据。个人感觉后面部分可以简化为： 排序关联表(主键的唯一值) 的方式。唯一值仅在关联表是一个，且根据主键查询的情况。

• CachingExecutor.query ->
  MappedStatement.getCache
  SimpleExecutor.query

可惜 MappedStatement.getCache 返回了空。没走缓存。

MyBatis 笔记

标签：ace   文件   manager   数据   data   mapper   ram   def   .data   

原文地址：https://www.cnblogs.com/newsea/p/8997606.html