The prefix "context" for element "context:property-placeholder" is not bound.
在文件头中引入：xmlns:context="http://www.springframework.org/schema/context"后
变成了
cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'context:property-placeholder'.
求解求解
在文件头中引入：xmlns:context="http://www.springframework.org/schema/context"
在xsi:schemaLocation这个字符串中添加context相关的解析文件
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.2.xsd。