Invalid bean definition with name 'dataSource' defined in class path resource [spring-mybatis.xml]:

项目更新并编译后启动服务器，报一下错误：

Invalid bean definition with name 'dataSource' defined in class path resource [spring-mybatis.xml]: Could not resolve placeholder 'initialSize' in string value "${initialSize}"; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'initialSize' in string value "${initialSize}"

报错信息的意思：在spring-mybatis.xml这个xml文件中，有个叫dataSource的bean的定义是非法的，原因是占位符${initialSize}无法解析，找到对应的jdbc.properties文件，发现是initialSize这个变量被注释掉了，放开注释即解决问题。