Myeclipse中.xml文件配置错误，出现"context:property-placeholder" is not bound错误

出现Exception in thread "main" org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 12 in XML document from class path resource [com/hsp/dispatch/beans.xml] is invalid; nested exception is org.xml.sax.SAXParseException: The prefix "context" for element "context:property-placeholder" is not bound.

原xml配置文件如下所示：

<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="
            http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
            http://www.springframework.org/schema/aop
            http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
            http://www.springframework.org/schema/tx
            http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

把它更改为如下所示（复制粘贴替换）：

<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"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
                            http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
                            http://www.springframework.org/schema/context
                            http://www.springframework.org/schema/context/spring-context-2.5.xsd
                            http://www.springframework.org/schema/tx
                            http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">