这种问题 在网上查的是说使用了重复的property-placeholder 可能是在别的xml 也用了property-placeholder
解决方法 加上 ignore-unresolvable="true"
Attribute : ignore-unresolvable
Specifies if failure to find the property value to replace a key should be ignored. Default is
"false", meaning that this placeholder configurer will raise an exception if it cannot resolve a
key. Set to "true" to allow the configurer to pass on the key to any others in the context that
have not yet visited the key in question.
大概意思是 开启后 允许配置程序将密钥传递给上下文中的任何其他配置程序