java - Spring @Value 注解无法解析

Question

我意识到这个问题已被问过无数次，但似乎没有一个解决方案适合我的情况。

我有一个基本的 Spring-WS 应用程序，我将其与单个 servlet 上下文组合在一起。我可以看到 @Component 注解的类和属性文件都在启动时被拾取，如下面的日志所示。但是，我的 @Value 注释字符串返回为 null。

1. 有人发现我的设置方式有什么问题吗？请随时询问我可能遗漏的任何其他信息。
2. 展望 future ，我可以使用哪些最佳方法来调查将来遇到的此类问题？

directmail-manager-servlet.xml:

<?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"
  xmlns:sws="http://www.springframework.org/schema/web-services"
  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
  http://www.springframework.org/schema/web-services http://www.springframework.org/schema/web-services/web-services-2.0.xsd
  http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <context:component-scan base-package="com.xxx.direct.mailserver"/>
    <context:property-placeholder location="classpath:manager.properties"/>

    <sws:annotation-driven/>

    <sws:dynamic-wsdl id="manager" portTypeName="EcwDirect"
        locationUri="/mailerManagerService/" targetNamespace="http://obfuscated.com/direct/definitions">
        <sws:xsd location="/WEB-INF/mailManagerRequest.xsd" />
    </sws:dynamic-wsdl>

</beans>

web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app 
    version="3.0" 
    xmlns="http://java.sun.com/xml/ns/javaee" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

    <display-name>xxxxxxxxx</display-name>

    <servlet>
        <servlet-name>directmail-manager</servlet-name>
        <servlet-class>org.springframework.ws.transport.http.MessageDispatcherServlet</servlet-class>
        <init-param>
            <param-name>transformWsdlLocations</param-name>
            <param-value>true</param-value>
        </init-param>
    </servlet>

    <servlet-mapping>
        <servlet-name>directmail-manager</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>

</web-app>

ma​​nager.properties:

mailserver.url="localhost"

我的带注释的类(class):

package com.xxx.direct.mailserver;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class TelnetMailServerUserController implements MailServerUserController {

    @Autowired
    @Value("${mailserver.url}")
    String mailserverUrl;

    @Override
    public void addUser(String username, String password) {

        System.out.println("server URL:" + mailserverUrl);
    }
}

使用该类的类:

@Service
public class MailManagerService {

    //TODO: craft and return response
    public void registerNewUser(List<Element> usersToAdd) {

        MailServerUserController userController = new TelnetMailServerUserController();

        //TODO: add users fo realz
        for(Element user : usersToAdd) {

            String emailAddress = user.getChildText("emailAddress", MailManagerEndpoint.NAMESPACE);
            String password = user.getChildText("password", MailManagerEndpoint.NAMESPACE);

            //TODO: log this:
            System.out.println("user " + emailAddress + " added");

            userController.addUser(emailAddress, password);

            //TODO: add to database
        }
    }
}

日志:

Apr 23, 2014 11:54:41 AM com.springsource.tcserver.security.PropertyDecoder <init>
INFO: tc Runtime property decoder using memory-based key
Apr 23, 2014 11:54:42 AM com.springsource.tcserver.security.PropertyDecoder <init>
INFO: tcServer Runtime property decoder has been initialized in 261 ms
Apr 23, 2014 11:54:42 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
Apr 23, 2014 11:54:42 AM com.springsource.tcserver.serviceability.rmi.JmxSocketListener init
INFO: Started up JMX registry on 127.0.0.1:6969 in 128 ms
Apr 23, 2014 11:54:42 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 959 ms
Apr 23, 2014 11:54:42 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Apr 23, 2014 11:54:42 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: VMware vFabric tc Runtime 2.9.3.RELEASE/7.0.42.A.RELEASE
Apr 23, 2014 11:54:42 AM org.apache.catalina.startup.HostConfig deployDescriptor
INFO: Deploying configuration descriptor C:\springsource\vfabric-tc-server-developer-2.9.3.RELEASE\base-instance\conf\Catalina\localhost\ROOT.xml
Apr 23, 2014 11:54:42 AM org.apache.catalina.startup.SetContextPropertiesRule begin
WARNING: [SetContextPropertiesRule]{Context} Setting property 'source' to 'org.eclipse.jst.jee.server:mail-server-manager' did not find a matching property.
Apr 23, 2014 11:54:44 AM org.apache.catalina.core.ApplicationContext log
INFO: No Spring WebApplicationInitializer types detected on classpath
Apr 23, 2014 11:54:44 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory C:\springsource\vfabric-tc-server-developer-2.9.3.RELEASE\base-instance\webapps\manager
Apr 23, 2014 11:54:44 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
Apr 23, 2014 11:54:44 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 1319 ms
Apr 23, 2014 11:54:44 AM org.apache.catalina.core.ApplicationContext log
INFO: Initializing Spring FrameworkServlet 'directmail-manager'
Apr 23, 2014 11:54:44 AM org.springframework.web.servlet.FrameworkServlet initServletBean
INFO: FrameworkServlet 'directmail-manager': initialization started
Apr 23, 2014 11:54:44 AM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing WebApplicationContext for namespace 'directmail-manager-servlet': startup date [Wed Apr 23 11:54:44 EDT 2014]; root of context hierarchy
Apr 23, 2014 11:54:44 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from ServletContext resource [/WEB-INF/directmail-manager-servlet.xml]
Apr 23, 2014 11:54:44 AM org.springframework.core.io.support.PropertiesLoaderSupport loadProperties
INFO: Loading properties file from class path resource [manager.properties]
Apr 23, 2014 11:54:45 AM org.springframework.ws.soap.addressing.server.AbstractAddressingEndpointMapping afterPropertiesSet
INFO: Supporting [WS-Addressing August 2004, WS-Addressing 1.0]
Apr 23, 2014 11:54:45 AM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@7c0f6d9: defining beans [mailManagerEndpoint,mailManagerService,telnetMailServerUserController,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.beans.factory.config.PropertyPlaceholderConfigurer#0,org.springframework.ws.server.endpoint.mapping.PayloadRootAnnotationMethodEndpointMapping#0,org.springframework.ws.soap.server.endpoint.mapping.SoapActionAnnotationMethodEndpointMapping#0,org.springframework.ws.soap.addressing.server.AnnotationActionEndpointMapping#0,org.springframework.ws.server.endpoint.adapter.method.dom.DomPayloadMethodProcessor#0,org.springframework.ws.server.endpoint.adapter.method.SourcePayloadMethodProcessor#0,org.springframework.ws.server.endpoint.adapter.method.jaxb.XmlRootElementPayloadMethodProcessor#0,org.springframework.ws.server.endpoint.adapter.method.jaxb.JaxbElementPayloadMethodProcessor#0,org.springframework.ws.server.endpoint.adapter.method.dom.JDomPayloadMethodProcessor#0,org.springframework.ws.server.endpoint.adapter.DefaultMethodEndpointAdapter#0,org.springframework.ws.soap.server.endpoint.SoapFaultAnnotationExceptionResolver#0,org.springframework.ws.soap.server.endpoint.SimpleSoapExceptionResolver#0,org.springframework.xml.xsd.SimpleXsdSchema#0,manager,org.springframework.context.annotation.ConfigurationClassPostProcessor.importAwareProcessor]; root of factory hierarchy
Apr 23, 2014 11:54:45 AM org.springframework.ws.soap.saaj.SaajSoapMessageFactory afterPropertiesSet
INFO: Creating SAAJ 1.3 MessageFactory with SOAP 1.1 Protocol
Apr 23, 2014 11:54:45 AM org.springframework.web.servlet.FrameworkServlet initServletBean
INFO: FrameworkServlet 'directmail-manager': initialization completed in 1012 ms
user test added
server URL:null

Answer 1

您没有使用 Spring 托管 bean。您正在自己创建一个对象。

MailServerUserController userController = new TelnetMailServerUserController();

在这种情况下，Spring 不参与处理 @Value 带注释的字段(或任何其他相关字段)。

相反，从上下文中获取 bean，然后注入(inject)它。

@Autowired
private MailServerUserController userController;