var x = 0 def IncreaseOne(): Int = { x += 1 x } def IncreaseOne() = { x += 1 x } def IncreaseOne = { x += 1 x } def IncreaseOne(): Unit = { x += 1 x } def IncreaseOne() { x += 1 x } def IncreaseOne = { x += 1 x } 上文中,前三个方法的定义是等同的,后三个也是等同的.规则非常简单,如果方法…
今天学Struts, tomcat报出了异常信息 Exception starting filter [struts2] Unable to load configuration.还有 No result type specified for result named 'success', 找了很久终于在stackoverflow上找到了报错原因,在struts.xml的配置文件中需要加上 namespace="/"; 这样就不会报错了 <package name="p…
使用mybatis时出现异常问题: 有如下的错误 Error querying database. Cause: org.apache.ibatis.executor.ExecutorException: A query was run and no Result Maps were found for the Mapped Statement 'user.insertUser!selectKey'. It's likely that neither a Result Type nor a Re…
media type(媒体类型)是css 2中的一个非常有用的属性,通过media type我们可以对不同的设备指定特定的样式,从而实现更丰富的界面.media query(媒体查询)是对media type的一种增强,是CSS 3的重要内容之一.随着移动互联网的发展,media query开始得到大家的重视. media type 让我们先了解一下media type,其实这个大家会比较熟悉一点,我们通常会用到的media type会是all 和screen,然后是print,一些网站会专门通…
Type 接口[重要] Type接口完整的定义: public interface java.lang.reflect.Type { /** * Returns a string describing this type, including information about any type parameters. * @implSpec The default implementation calls {@code toString}. * @return a string describ…
首先说明一下遇到的问题: PG数据库,对其中的某张表增加一列后,应用报错,信息如下: 应用使用相关框架如下:SpringBoot.MyBatis. ### Cause: org.postgresql.util.PSQLException: ERROR: cached plan must not change result type ; uncategorized SQLException for SQL []; SQL state [0A000]; error code [0]; ERROR:…
ExecutorException: A query was run and no Result Maps were found for the Mapped Statement 'com.win.mall.dao.CartMapper.test'. It's likely that neither a Result Type nor a Result Map was specified. 原因:mybatis没有resultMap报错 在mapper文件的 select 标签中没有指定 res…