java - PropertyPlaceholderConfigurer 不适用于 ClassPathXmlApplicationContext

Question

我尝试使用 PropertyPlaceholderConfigurer 加载属性文件中的一些变量，但它不起作用。互联网上的一些网站建议当 spring aop 不在类路径中时会出现问题，但我确保 aop 框架在我的项目中。这是我的 springContext.xml:

    <!-- Register all placeholder locations -->
<bean
    class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer" >
    <property name="order" value="0" />
    <property name="ignoreUnresolvablePlaceholders" value="true" />
    <property name="locations">
        <list>
            <value>file:/mypath/file.properties</value>             
        </list>
    </property>
</bean>

<!-- Register all placeholder locations -->
<password-decrypter order="10" id="passwordConfigurer">
<decrypter algorithm="PBEWithSHAAnd128BitRC4" key="${Encryption.key}" />
    <decryption-entries>
        <decryption-entry bean-ref="ds" properties="password" />
    </decryption-entries>
</password-decrypter>

这是抛出错误:

Caused by: org.xml.sax.SAXParseException: cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'password-decrypter'.
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.createSAXParseException(ErrorHandlerWrapper.java:195)
at com.sun.org.apache.xerces.internal.util.ErrorHandlerWrapper.error(ErrorHandlerWrapper.java:131)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:384)
at com.sun.org.apache.xerces.internal.impl.XMLErrorReporter.reportError(XMLErrorReporter.java:318)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator$XSIErrorReporter.reportError(XMLSchemaValidator.java:417)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.reportSchemaError(XMLSchemaValidator.java:3182)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.handleStartElement(XMLSchemaValidator.java:1927)
at com.sun.org.apache.xerces.internal.impl.xs.XMLSchemaValidator.startElement(XMLSchemaValidator.java:705)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:400)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2755)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:648)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:140)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:511)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:808)
at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737)
at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:119)
at com.sun.org.apache.xerces.internal.parsers.DOMParser.parse(DOMParser.java:235)
at com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderImpl.parse(DocumentBuilderImpl.java:284)
at org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument(DefaultDocumentLoader.java:76)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:351)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:303)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:280)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:131)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:147)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:173)
at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:112)
at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:79)
at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:101)
at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:389)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:324)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:91)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:75)
at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:65)

在容器外部运行程序以将 PropertyPlaceholderConfigurer 与 ClassPathXmlApplicationContext 结合使用时，我是否需要做一些不同的事情？

Answer 1

还有一种替代方法。你可以按照下面提到的方法尝试一下。

不要在 applicationContext.xml 中定义 PropertyPlaceholderConfigurer，而是使用以下代码在 ServletContextListener 中定义它

    PropertyPlaceholderConfigurer configurer = new PropertyPlaceholderConfigurer();
    ResourceLoader resourceLoader = new DefaultResourceLoader();
    Resource resource = resourceLoader.getResource("classpath:localDB.properties");

    configurer.setLocation(resource);
    configurer.postProcessBeanFactory(beanFactory);

这里的beanFactory是一个使用ClassPathResource创建的XmlBeanFactory。

属性文件 localDB.properties 可以包含适当的值，并且它们可以在 applicationContext.xml 中用作 ${Encryption.key}，这里 Encryption.key 是来自属性文件