ERROR org.springframework.boot.SpringApplication - Application run failed org.springframework.beans.

今天突然需要用到spring里的context时，就直接在xml文件里面导入 xmlns:context="http://www.springframework.org/schema/context"使用

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd">
    <context:property-placeholder location="classpath:captcha/captcha.properties" />

运行项目就报错了

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-03-20 10:51:59.732 [restartedMain] ERROR org.springframework.boot.
SpringApplication - Application run failed
org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 7 in XML document from class path resource [kaptcha.xml] is invalid; 
nested exception is org.xml.sax.SAXParseException; lineNumber: 7; columnNumber: 85; cvc-complex-type.2.4.c: 通配符的匹配很全面, 但无法找到元素 'context:property-placeholder' 的声明。
	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:402)
	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:338)
	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:310)
	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:188)
	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:224)
	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:195)
	at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.lambda$loadBeanDefinitionsFromImportedResources$0(ConfigurationClassBeanDefinitionReader.java:390)
	at java.util.LinkedHashMap.forEach(LinkedHashMap.java:684)

检测之后发现没有导入命名空间，

解决方法

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context 
       http://www.springframework.org/schema/context/spring-context.xsd">
    <context:property-placeholder location="classpath:captcha/captcha.properties" />