SpringMVC-Spring容器启动加载Mybitas过程

柔光的暖阳◎ 2023-06-27 05:55 27阅读 0赞

*  本案例用的是tomcat做的servlet容器
 *  浅谈一下spring和springMVC的关系，spring项目下有很多模块，mvc是其中之一，各个子模块与父模块相同，父模块不能链接子模块
 *  **在mvc项目初始化的时候会初始化两个Context,一个是Root WebApplication(mvc的context),一个是ApplicationContext（spring容器）**
 *  spring容器负责ioc aop ，mvc容器负责请求的转发视图解析，mvc容器可以请求spring容器，反之不行
 *  当servlet发布ServletContextEvent事件的时候会触发配置在web.xml里的监听
 *  **Dao层实际上是一个代理对象，在执行的时候先走MapperProxy.invoke()**

<listener>
    		<description>spring监听器</description>
    		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    	</listener>

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1eGllMTM_size_16_color_FFFFFF_t_70]\`

public void refresh() throws BeansException, IllegalStateException {
        	synchronized(this.startupShutdownMonitor) {
        	//读取contextConfigLocation值
            this.prepareRefresh();
            //创建beanFactory
            ConfigurableListableBeanFactory beanFactory = this.obtainFreshBeanFactory();
            //将spring.xml和mybitas.xml的扫描路径下的类和bean加载到beanFactory
            this.prepareBeanFactory(beanFactory);
            try {
                this.postProcessBeanFactory(beanFactory);
                this.invokeBeanFactoryPostProcessors(beanFactory);
                this.registerBeanPostProcessors(beanFactory);
                this.initMessageSource();
                this.initApplicationEventMulticaster();
                this.onRefresh();
                this.registerListeners();
                //发布加载将bean里面的name值设置到对象对应的属性里面
                this.finishBeanFactoryInitialization(beanFactory);
                this.finishRefresh();
            } catch (BeansException var9) {
                if (this.logger.isWarnEnabled()) {
                    this.logger.warn("Exception encountered during context initialization - cancelling refresh attempt: " + var9);
                }
    
                this.destroyBeans();
                this.cancelRefresh(var9);
                throw var9;
            } finally {
                this.resetCommonCaches();
            }
    
        }
    }
    `

*  初始化MapperScannerConfigurer对象，并将datasource和dao路径设置进去  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1eGllMTM_size_16_color_FFFFFF_t_70 1]  
    设置![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1eGllMTM_size_16_color_FFFFFF_t_70 2]
 *  2里面的主要方法就是执行了**this.buildSqlSessionFactory()**;
 *  这个方法执行了mybitas 配置文件初始化的工作
 *  配置文件的加载的精华就在configuration里面，如下
 *  **reflectorFactory**存的就是xml里面的entity引用
 *  **interceptorChain**存的拦截器，[用法详见][Link 1]
 *  **mappedStatements**这个是重头,将dao.method做key，自个写的sql做value存在这
 *  resultMaps看名字就知道是所有的resultMap  
    总之mapper.xml解析的所有东西都在这  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3h1eGllMTM_size_16_color_FFFFFF_t_70 3]WATING

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[Link 1]: https://blog.csdn.net/xuxie13/article/details/103741477
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