SqlSessionFactoryBean详解

水深无声 2022-11-30 04:19 140阅读 0赞

### 文章目录 ###

*   *  官方学习地址
     *  作用
     *  代码分析
     *  buildSqlSessionFactory方法

## 官方学习地址 ##

官网:[http://mybatis.org/spring/zh/factorybean.html][http_mybatis.org_spring_zh_factorybean.html]

## 作用 ##

## 代码分析 ##

类图:  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MzY2MDYz_size_16_color_FFFFFF_t_70_pic_center]  
继承的接口:

*  InitializingBean:这个接口的作用是spring初始化的时候会执行实现了InitializingBean接口的afterPropertiesSet方法;具体怎么执行暂时就不说了;
 *  ApplicationListener接口作用是在spring容器执行的各个阶段进行监听,SqlSessionFactoryBean实现这个接口是为了容器刷新的时候,更新sqlSessionFactory;可以自己看下onApplicationEvent方法实现;
 *  FactoryBean:实现这个接口表示这个类是一个工厂bean,通常是为了给返回的类进行加工处理的,而且获取类返回的是通过getObj返回的;

看这个类就从入口开始看,通过这个方法afterPropertiesSet;

@Override
      public void afterPropertiesSet() throws Exception { 
        //dataSource是必须要配置的
        notNull(dataSource, "Property 'dataSource' is required");
        notNull(sqlSessionFactoryBuilder, "Property 'sqlSessionFactoryBuilder' is required");
        state((configuration == null && configLocation == null) || !(configuration != null && configLocation != null),
                  "Property 'configuration' and 'configLocation' can not specified with together");
    
        //主要逻辑都在buildSqlSessionFactory方法,创建sqlSessionFactory,getObject就是返回的sqlSessionFactory 
        this.sqlSessionFactory = buildSqlSessionFactory();
      }
    
      @Override
      public SqlSessionFactory getObject() throws Exception { 
        if (this.sqlSessionFactory == null) { 
          afterPropertiesSet();
        }
    
        return this.sqlSessionFactory;
      }

## buildSqlSessionFactory方法 ##

看buildSqlSessionFactory方法,首先要先看Configuration类:  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MzY2MDYz_size_16_color_FFFFFF_t_70_pic_center 1]  
大概看一下,发现这个类其实就是我们在mybatis配置文件里面配置的属性,创建SqlSessionFactory实际就是不断给configuration赋值的过程.  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MzY2MDYz_size_16_color_FFFFFF_t_70_pic_center 2]  
然后后面一大段都是对configuration进行赋值;  
详情可以直接看官网:[https://mybatis.org/mybatis-3/zh/configuration.html][https_mybatis.org_mybatis-3_zh_configuration.html]  
我举几个常见的:  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MzY2MDYz_size_16_color_FFFFFF_t_70_pic_center 3]  
XMLMapperBuilder的主要解析:  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MzY2MDYz_size_16_color_FFFFFF_t_70_pic_center 4]

最后就是通过sqlSessionFactoryBuilder来创建SqlSessionFactory;

[http_mybatis.org_spring_zh_factorybean.html]: http://mybatis.org/spring/zh/factorybean.html
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MzY2MDYz_size_16_color_FFFFFF_t_70_pic_center 1]: /images/20221124/391a5067279e4b14b5623b308d679368.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MzY2MDYz_size_16_color_FFFFFF_t_70_pic_center 2]: /images/20221124/eac98fd522254597b6fee60f25895905.png
[https_mybatis.org_mybatis-3_zh_configuration.html]: https://mybatis.org/mybatis-3/zh/configuration.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MzY2MDYz_size_16_color_FFFFFF_t_70_pic_center 3]: /images/20221124/aec8cf395b2247f6bd3c6544a63c5fab.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MzY2MDYz_size_16_color_FFFFFF_t_70_pic_center 4]: /images/20221124/7084ee3df0bf4a3b890ea39f7b9b94e2.png