Spring Application Context未從application.properties文件獲取屬性

Question

我正在用spring和gradle創建一個控制台應用程序。 我想在我的application.properties文件中包含信息以供程序訪問。

上面是此工具的類結構的圖片。

這是applicationContext文件

    <?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:util="http://www.springframework.org/schema/util"

       xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/util
            http://www.springframework.org/schema/util/spring-util-3.0.xsd">
    <util:properties id="app_properties" location="classpath:config/application.properties"/>
</beans>

這是application.properties文件

tenant.cache.refresh=10

我現在正在嘗試在主類（驅動程序）中使用此鍵

public class Driver {

    @Value("#{app_properties['tenant.cache.refresh']}")
    private static Integer cacheRefreshTime;

    private static final org.slf4j.Logger LOGGER = LoggerFactory.getLogger(Driver.class);
    public static void main(String[] args) throws IOException {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        System.out.println(cacheRefreshTime);
    }

當我這樣做時，將輸出null，說明cacheRefreshTime尚未初始化。

堆棧跟蹤看起來像

11:04:09.552 [main] DEBUG o.s.core.env.StandardEnvironment - Adding [systemProperties] PropertySource with lowest search precedence
11:04:09.558 [main] DEBUG o.s.core.env.StandardEnvironment - Adding [systemEnvironment] PropertySource with lowest search precedence
11:04:09.558 [main] DEBUG o.s.core.env.StandardEnvironment - Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
11:04:09.561 [main] INFO  o.s.c.s.ClassPathXmlApplicationContext - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@4de6b200: startup date [Wed Jul 30 11:04:09 PDT 2014]; root of context hierarchy
11:04:09.590 [main] DEBUG o.s.core.env.StandardEnvironment - Adding [systemProperties] PropertySource with lowest search precedence
11:04:09.590 [main] DEBUG o.s.core.env.StandardEnvironment - Adding [systemEnvironment] PropertySource with lowest search precedence
11:04:09.590 [main] DEBUG o.s.core.env.StandardEnvironment - Initialized StandardEnvironment with PropertySources [systemProperties,systemEnvironment]
11:04:09.600 [main] INFO  o.s.b.f.xml.XmlBeanDefinitionReader - Loading XML bean definitions from class path resource [applicationContext.xml]
11:04:09.615 [main] DEBUG o.s.b.f.xml.DefaultDocumentLoader - Using JAXP provider [com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl]
11:04:09.641 [main] DEBUG o.s.b.f.xml.PluggableSchemaResolver - Loading schema mappings from [META-INF/spring.schemas]
11:04:09.646 [main] DEBUG o.s.b.f.xml.PluggableSchemaResolver - Loaded schema mappings: {http://www.springframework.org/schema/jee/spring-jee-3.2.xsd=org/springframework/ejb/config/spring-jee-3.2.xsd, http://www.springframework.org/schema/util/spring-util.xsd=org/springframework/beans/factory/xml/spring-util-4.0.xsd, http://www.springframework.org/schema/task/spring-task.xsd=org/springframework/scheduling/config/spring-task-4.0.xsd, http://www.springframework.org/schema/beans/spring-beans-3.1.xsd=org/springframework/beans/factory/xml/spring-beans-3.1.xsd, http://www.springframework.org/schema/cache/spring-cache.xsd=org/springframework/cache/config/spring-cache-4.0.xsd, http://www.springframework.org/schema/aop/spring-aop-3.0.xsd=org/springframework/aop/config/spring-aop-3.0.xsd, http://www.springframework.org/schema/task/spring-task-3.1.xsd=org/springframework/scheduling/config/spring-task-3.1.xsd, http://www.springframework.org/schema/aop/spring-aop-2.0.xsd=org/springframework/aop/config/spring-aop-2.0.xsd, http://www.springframework.org/schema/aop/spring-aop-4.0.xsd=org/springframework/aop/config/spring-aop-4.0.xsd, http://www.springframework.org/schema/tool/spring-tool-2.5.xsd=org/springframework/beans/factory/xml/spring-tool-2.5.xsd, http://www.springframework.org/schema/beans/spring-beans.xsd=org/springframework/beans/factory/xml/spring-beans-4.0.xsd, http://www.springframework.org/schema/jee/spring-jee-2.5.xsd=org/springframework/ejb/config/spring-jee-2.5.xsd, http://www.springframework.org/schema/jdbc/spring-jdbc-3.1.xsd=org/springframework/jdbc/config/spring-jdbc-3.1.xsd, http://www.springframework.org/schema/tool/spring-tool-3.1.xsd=org/springframework/beans/factory/xml/spring-tool-3.1.xsd, http://www.springframework.org/schema/jee/spring-jee-3.1.xsd=org/springframework/ejb/config/spring-jee-3.1.xsd, http://www.springframework.org/schema/aop/spring-aop.xsd=org/springframework/aop/config/spring-aop-4.0.xsd, http://www.springframework.org/schema/tx/spring-tx-3.2.xsd=org/springframework/transaction/config/spring-tx-3.2.xsd, http://www.springframework.org/schema/context/spring-context-3.2.xsd=org/springframework/context/config/spring-context-3.2.xsd, http://www.springframework.org/schema/beans/spring-beans-2.0.xsd=org/springframework/beans/factory/xml/spring-beans-2.0.xsd, http://www.springframework.org/schema/util/spring-util-3.2.xsd=org/springframework/beans/factory/xml/spring-util-3.2.xsd, http://www.springframework.org/schema/lang/spring-lang-3.2.xsd=org/springframework/scripting/config/spring-lang-3.2.xsd, http://www.springframework.org/schema/beans/spring-beans-4.0.xsd=org/springframework/beans/factory/xml/spring-beans-4.0.xsd, http://www.springframework.org/schema/beans/spring-beans-3.0.xsd=org/springframework/beans/factory/xml/spring-beans-3.0.xsd, http://www.springframework.org/schema/cache/spring-cache-3.2.xsd=org/springframework/cache/config/spring-cache-3.2.xsd, http://www.springframework.org/schema/task/spring-task-3.0.xsd=org/springframework/scheduling/config/spring-task-3.0.xsd, http://www.springframework.org/schema/task/spring-task-4.0.xsd=org/springframework/scheduling/config/spring-task-4.0.xsd, http://www.springframework.org/schema/tx/spring-tx-2.5.xsd=org/springframework/transaction/config/spring-tx-2.5.xsd, http://www.springframework.org/schema/context/spring-context-2.5.xsd=org/springframework/context/config/spring-context-2.5.xsd, http://www.springframework.org/schema/jdbc/spring-jdbc-4.0.xsd=org/springframework/jdbc/config/spring-jdbc-4.0.xsd, http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd=org/springframework/jdbc/config/spring-jdbc-3.0.xsd, http://www.springframework.org/schema/tool/spring-tool-3.0.xsd=org/springframework/beans/factory/xml/spring-tool-3.0.xsd, http://www.springframework.org/schema/tx/spring-tx.xsd=org/springframework/transaction/config/spring-tx-4.0.xsd, http://www.springframework.org/schema/lang/spring-lang.xsd=org/springframework/scripting/config/spring-lang-4.0.xsd, http://www.springframework.org/schema/tool/spring-tool-2.0.xsd=org/springframework/beans/factory/xml/spring-tool-2.0.xsd, http://www.springframework.org/schema/util/spring-util-2.5.xsd=org/springframework/beans/factory/xml/spring-util-2.5.xsd, http://www.springframework.org/schema/lang/spring-lang-2.5.xsd=org/springframework/scripting/config/spring-lang-2.5.xsd, http://www.springframework.org/schema/tool/spring-tool-4.0.xsd=org/springframework/beans/factory/xml/spring-tool-4.0.xsd, http://www.springframework.org/schema/aop/spring-aop-3.2.xsd=org/springframework/aop/config/spring-aop-3.2.xsd, http://www.springframework.org/schema/jee/spring-jee-3.0.xsd=org/springframework/ejb/config/spring-jee-3.0.xsd, http://www.springframework.org/schema/tx/spring-tx-3.1.xsd=org/springframework/transaction/config/spring-tx-3.1.xsd, http://www.springframework.org/schema/jee/spring-jee-2.0.xsd=org/springframework/ejb/config/spring-jee-2.0.xsd, http://www.springframework.org/schema/context/spring-context-3.1.xsd=org/springframework/context/config/spring-context-3.1.xsd, http://www.springframework.org/schema/jee/spring-jee-4.0.xsd=org/springframework/ejb/config/spring-jee-4.0.xsd, http://www.springframework.org/schema/util/spring-util-3.1.xsd=org/springframework/beans/factory/xml/spring-util-3.1.xsd, http://www.springframework.org/schema/lang/spring-lang-3.1.xsd=org/springframework/scripting/config/spring-lang-3.1.xsd, http://www.springframework.org/schema/cache/spring-cache-3.1.xsd=org/springframework/cache/config/spring-cache-3.1.xsd, http://www.springframework.org/schema/context/spring-context.xsd=org/springframework/context/config/spring-context-4.0.xsd, http://www.springframework.org/schema/jee/spring-jee.xsd=org/springframework/ejb/config/spring-jee-4.0.xsd, http://www.springframework.org/schema/aop/spring-aop-2.5.xsd=org/springframework/aop/config/spring-aop-2.5.xsd, http://www.springframework.org/schema/jdbc/spring-jdbc.xsd=org/springframework/jdbc/config/spring-jdbc-4.0.xsd, http://www.springframework.org/schema/beans/spring-beans-3.2.xsd=org/springframework/beans/factory/xml/spring-beans-3.2.xsd, http://www.springframework.org/schema/tx/spring-tx-2.0.xsd=org/springframework/transaction/config/spring-tx-2.0.xsd, http://www.springframework.org/schema/aop/spring-aop-3.1.xsd=org/springframework/aop/config/spring-aop-3.1.xsd, http://www.springframework.org/schema/tx/spring-tx-4.0.xsd=org/springframework/transaction/config/spring-tx-4.0.xsd, http://www.springframework.org/schema/task/spring-task-3.2.xsd=org/springframework/scheduling/config/spring-task-3.2.xsd, http://www.springframework.org/schema/context/spring-context-4.0.xsd=org/springframework/context/config/spring-context-4.0.xsd, http://www.springframework.org/schema/tx/spring-tx-3.0.xsd=org/springframework/transaction/config/spring-tx-3.0.xsd, http://www.springframework.org/schema/context/spring-context-3.0.xsd=org/springframework/context/config/spring-context-3.0.xsd, http://www.springframework.org/schema/tool/spring-tool.xsd=org/springframework/beans/factory/xml/spring-tool-4.0.xsd, http://www.springframework.org/schema/util/spring-util-3.0.xsd=org/springframework/beans/factory/xml/spring-util-3.0.xsd, http://www.springframework.org/schema/lang/spring-lang-3.0.xsd=org/springframework/scripting/config/spring-lang-3.0.xsd, http://www.springframework.org/schema/util/spring-util-2.0.xsd=org/springframework/beans/factory/xml/spring-util-2.0.xsd, http://www.springframework.org/schema/cache/spring-cache-4.0.xsd=org/springframework/cache/config/spring-cache-4.0.xsd, http://www.springframework.org/schema/lang/spring-lang-2.0.xsd=org/springframework/scripting/config/spring-lang-2.0.xsd, http://www.springframework.org/schema/util/spring-util-4.0.xsd=org/springframework/beans/factory/xml/spring-util-4.0.xsd, http://www.springframework.org/schema/lang/spring-lang-4.0.xsd=org/springframework/scripting/config/spring-lang-4.0.xsd, http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd=org/springframework/jdbc/config/spring-jdbc-3.2.xsd, http://www.springframework.org/schema/tool/spring-tool-3.2.xsd=org/springframework/beans/factory/xml/spring-tool-3.2.xsd, http://www.springframework.org/schema/beans/spring-beans-2.5.xsd=org/springframework/beans/factory/xml/spring-beans-2.5.xsd}
11:04:09.651 [main] DEBUG o.s.b.f.xml.PluggableSchemaResolver - Found XML schema [http://www.springframework.org/schema/beans/spring-beans.xsd] in classpath: org/springframework/beans/factory/xml/spring-beans-4.0.xsd
11:04:09.689 [main] DEBUG o.s.b.f.xml.PluggableSchemaResolver - Found XML schema [http://www.springframework.org/schema/util/spring-util-3.0.xsd] in classpath: org/springframework/beans/factory/xml/spring-util-3.0.xsd
11:04:09.693 [main] DEBUG o.s.b.f.xml.PluggableSchemaResolver - Found XML schema [http://www.springframework.org/schema/tool/spring-tool-3.0.xsd] in classpath: org/springframework/beans/factory/xml/spring-tool-3.0.xsd
11:04:09.701 [main] DEBUG o.s.b.f.x.DefaultBeanDefinitionDocumentReader - Loading bean definitions
11:04:09.711 [main] DEBUG o.s.b.f.x.DefaultNamespaceHandlerResolver - Loaded NamespaceHandler mappings: {http://www.springframework.org/schema/p=org.springframework.beans.factory.xml.SimplePropertyNamespaceHandler, http://www.springframework.org/schema/util=org.springframework.beans.factory.xml.UtilNamespaceHandler, http://www.springframework.org/schema/jee=org.springframework.ejb.config.JeeNamespaceHandler, http://www.springframework.org/schema/aop=org.springframework.aop.config.AopNamespaceHandler, http://www.springframework.org/schema/jdbc=org.springframework.jdbc.config.JdbcNamespaceHandler, http://www.springframework.org/schema/cache=org.springframework.cache.config.CacheNamespaceHandler, http://www.springframework.org/schema/c=org.springframework.beans.factory.xml.SimpleConstructorNamespaceHandler, http://www.springframework.org/schema/tx=org.springframework.transaction.config.TxNamespaceHandler, http://www.springframework.org/schema/task=org.springframework.scheduling.config.TaskNamespaceHandler, http://www.springframework.org/schema/lang=org.springframework.scripting.config.LangNamespaceHandler, http://www.springframework.org/schema/context=org.springframework.context.config.ContextNamespaceHandler}
11:04:09.723 [main] DEBUG o.s.b.f.xml.XmlBeanDefinitionReader - Loaded 1 bean definitions from location pattern [applicationContext.xml]
11:04:09.723 [main] DEBUG o.s.c.s.ClassPathXmlApplicationContext - Bean factory for org.springframework.context.support.ClassPathXmlApplicationContext@4de6b200: org.springframework.beans.factory.support.DefaultListableBeanFactory@e0e2081: defining beans [app_properties]; root of factory hierarchy
11:04:09.737 [main] DEBUG o.s.c.s.ClassPathXmlApplicationContext - Unable to locate MessageSource with name 'messageSource': using default [org.springframework.context.support.DelegatingMessageSource@693a2c6a]
11:04:09.739 [main] DEBUG o.s.c.s.ClassPathXmlApplicationContext - Unable to locate ApplicationEventMulticaster with name 'applicationEventMulticaster': using default [org.springframework.context.event.SimpleApplicationEventMulticaster@43f49e84]
11:04:09.740 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@e0e2081: defining beans [app_properties]; root of factory hierarchy
11:04:09.740 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Creating shared instance of singleton bean 'app_properties'
11:04:09.741 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Creating instance of bean 'app_properties'
11:04:09.751 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Eagerly caching bean 'app_properties' to allow for resolving potential circular references
11:04:09.785 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Invoking afterPropertiesSet() on bean with name 'app_properties'
11:04:09.785 [main] INFO  o.s.b.f.config.PropertiesFactoryBean - Loading properties file from class path resource [config/application.properties]
11:04:09.786 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Finished creating instance of bean 'app_properties'
11:04:09.788 [main] DEBUG o.s.c.s.ClassPathXmlApplicationContext - Unable to locate LifecycleProcessor with name 'lifecycleProcessor': using default [org.springframework.context.support.DefaultLifecycleProcessor@10ea348e]
11:04:09.788 [main] DEBUG o.s.b.f.s.DefaultListableBeanFactory - Returning cached instance of singleton bean 'lifecycleProcessor'
11:04:09.789 [main] DEBUG o.s.c.e.PropertySourcesPropertyResolver - Searching for key 'spring.liveBeansView.mbeanDomain' in [systemProperties]
11:04:09.789 [main] DEBUG o.s.c.e.PropertySourcesPropertyResolver - Searching for key 'spring.liveBeansView.mbeanDomain' in [systemEnvironment]
11:04:09.790 [main] DEBUG o.s.c.e.PropertySourcesPropertyResolver - Could not find key 'spring.liveBeansView.mbeanDomain' in any property source. Returning [null]
null

任何想法如何解決這一問題？ 提前致謝。

我試圖使該字段不是靜態的，並且還嘗試添加PropertyPlaceholderConfigurer。 我的applicationContext看起來像

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

        <bean id="properties" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
            <property name="locations">
                <list>
                    <value>classpath:config/application.properties</value>
                </list>
            </property>
        </bean>
    </beans>

當我運行此代碼時，我得到了相同的堆棧跟蹤。 空仍然被打印。 我創建了一個單獨的類，該類具有一個非靜態字段，並且僅具有一個打印該字段的方法。 然后，我的主類創建該虛擬類的實例，並調用print字段方法。 此時將打印null。

在我的applicationContext文件中，當我嘗試說class =“ org.spring ...”時，在第7行出現錯誤

它說類或接口除外。 好像找不到課程。 但是我在build.gralde中包含了以下依賴項

    compile "org.springframework:spring-context"
compile "org.springframework:spring-context-support"

我的代碼編譯並運行良好，問題是盡管堆棧跟蹤表明已找到並加載了application.properites，但該字段為null。

ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
@Value("#{app_properties['tenant.cache.refresh']}")
private Integer cacheRefreshTime;

Answer 1

Spring不能（盡管可以）工作static字段。 使它成為實例字段，創建一個包含它的類型的bean並檢查它。 請注意，您將需要一個PropertyPlaceholderConfigurer來進行處理。 僅創建Properties bean是不夠的。

您還需要使用

<context:annotation-config />