那些遇到过的问题

无法解析字符串值中的占位符

Hwe*_*wen 71 java spring

我试图使用.properties文件中的属性,但它似乎不起作用.

这是我的代码:

@Service("ServiceFTP")
@Transactional
public class ServiceFTPImpl implements ServiceFTP {

@Value("${project.ftp.adresse}")
private String adresse;

@Value("${project.ftp.login}")
private String compte;

@Value("${project.ftp.password}")
private String motDePasse;

@Value("${project.ftp.root}")
private String ROOT;

[...]

}
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此类使用@Value注释来获取属性.它也被声明为Spring Service并链接到我的infraContext.xml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:context="http://www.springframework.org/schema/context"
   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd">

<context:property-placeholder location="classpath:context-core.properties"/>

[...]

</beans>
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使用context:property-placeholder,我将此文件链接到我的context-core.properties文件:

project.ftp.adresse = localhost
project.ftp.login = anonymous
project.ftp.password =
project.ftp.root = /anonymous/
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这确实有道理,对吗？

但是当我尝试启动我的项目时,Tomcat抛出了这个异常:

    ERROR [context.ContextLoader.initWebApplicationContext()] Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'ServiceFTP': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.lang.String project.sins.service.impl.ServiceFTPImpl.adresse; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'project.ftp.adresse' in string value "${project.ftp.adresse}"
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:607)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:925)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:472)
    at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:388)
    at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:293)
    at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:111)
    at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4887)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5381)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:633)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:657)
    at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1636)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:722)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.lang.String project.sins.service.impl.ServiceFTPImpl.adresse; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'project.ftp.adresse' in string value "${project.ftp.adresse}"
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:513)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:92)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284)
    ... 27 more
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'project.ftp.adresse' in string value "${project.ftp.adresse}"
    at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:173)
    at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:125)
    at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:151)
    at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:142)
    at org.springframework.context.support.PropertySourcesPlaceholderConfigurer$2.resolveStringValue(PropertySourcesPlaceholderConfigurer.java:169)
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:748)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:740)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:730)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:485)
    ... 29 more
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或者,简而言之: java.lang.IllegalArgumentException: Could not resolve placeholder 'project.ftp.adresse' in string value "${project.ftp.adresse}"

编辑:

这是我的web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://java.sun.com/xml/ns/javaee"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
         id="sins" version="2.5">

    <display-name>Project</display-name>

    <listener>
        <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
    </listener>

    <context-param>
        <param-name>log4jExposeWebAppRoot</param-name>
        <param-value>false</param-value>
    </context-param>

    <filter>
        <filter-name>ExpiresFilter</filter-name>
        <filter-class>org.apache.catalina.filters.ExpiresFilter</filter-class>
        <init-param>
            <param-name>ExpiresByType text/html</param-name>
            <param-value>now plus 0 seconds</param-value>
        </init-param>
        <init-param>
            <param-name>ExpiresByType application/json</param-name>
            <param-value>now plus 0 seconds</param-value>
        </init-param>
    </filter>

    <filter-mapping>
        <filter-name>ExpiresFilter</filter-name>
        <url-pattern>/*</url-pattern>
        <dispatcher>REQUEST</dispatcher>
    </filter-mapping>

    <filter>
        <filter-name>EncodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>EncodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <filter>
        <filter-name>Spring OpenEntityManagerInViewFilter</filter-name>
        <filter-class>
            org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter
        </filter-class>
    </filter>

    <filter-mapping>
        <filter-name>Spring OpenEntityManagerInViewFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <listener>
        <listener-class>org.apache.struts2.tiles.StrutsTilesListener</listener-class>
    </listener>

    <context-param>
        <param-name>
            org.apache.tiles.impl.BasicTilesContainer.DEFINITIONS_CONFIG
        </param-name>
        <param-value>
            /WEB-INF/tiles/user.xml
        </param-value>
    </context-param>

    <resource-ref>
        <res-ref-name>jdbc/si_nsg</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>
    </resource-ref>

    <session-config>
        <session-timeout>60</session-timeout>
    </session-config>

</web-app>
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我的infraContext.xml是在另一个名为applicationContext.xml的.xml文件中导入的:

<?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:jee="http://www.springframework.org/schema/jee"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
    http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.1.xsd">

    <bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
        <property name="environment">
            <bean class="org.springframework.web.context.support.StandardServletEnvironment"/>
        </property>
    </bean>

    <import resource="classpath:securityContext.xml"/>

    [...]
    <import resource="classpath:project/sins/persistenceContext.xml"/>

    <import resource="classpath:project/sins/infraContext.xml"/>

</beans>
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我显然遗漏了一些东西,但我无法弄清楚是什么.

如果您需要更多详细信息,请告诉我,因为这是我的第一个问题,我会尽快回答:).

M. *_*num 68

在您的配置中,您有2个PropertySourcesPlaceholderConfigurer实例.

applicationContext.xml中

<bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
    <property name="environment">
        <bean class="org.springframework.web.context.support.StandardServletEnvironment"/>
    </property>
</bean>
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infraContext.xml

<context:property-placeholder location="classpath:context-core.properties"/>
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默认情况下,a PlaceholderConfigurer会快速失败,因此如果占位符无法解析,则会抛出异常.applicationContext.xml文件中的实例没有属性,因此在所有占位符上都会失败.

解决方案:从applicationContext.xml中删除一个,因为它不会添加任何只会破坏的东西.

  • 不,你可以拥有多个,但默认情况下,如果找不到占位符,它们会快速失败.您可以通过将`ignore-unresolved-placeholders`设置为`true`来禁用它. (10认同)
  • 我如何在带有注释的 Spring Boot 中处理它？ (3认同)

ola*_*tno 15

我在 Spring Boot 应用程序中遇到了类似的问题。

当您将属性配置添加到主应用程序 SCR 目录中的 application.properties 文件时，请确保对 test 目录下的 application.properties 文件执行相同的操作。

小智 9

您也可以尝试默认值。spring 值注释

\n\n

可以为可能未定义的属性提供默认值。在此示例中，将注入值 \xe2\x80\x9csome default\xe2\x80\x9d：

\n\n
@Value("${unknown.param:some default}")\nprivate String someDefault;\n
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如果在属性文件中将相同的属性定义为系统属性，则将应用系统属性。

\n

小智 8

我在我的微服务中遇到同样的错误，每当你在程序中声明 @Value 注释时，即@Value("${project.api.key}")

确保具有相同值的 application.properties 文件不应为空白project.api.key= 添加一些值

MostIMP：否则会抛出错误“创建名为'ServiceFTP'的bean时出错：注入自动装配的依赖项”

use*_*552 7

我遇到了同样的问题，通过添加解决了它

<filtering>true</filtering>
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在 pom.xml 中：

之前（不起作用）：

<build>
    <resources>
        <resource>
            <directory>src/main/resources</directory>               
        </resource>
    </resources>
</build>
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之后（它有效）：

<build>
    <resources>
        <resource>
            <directory>src/main/resources</directory>
            <filtering>true</filtering>
        </resource>
    </resources>
</build>
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之后，您只需运行mvn clean install并部署应用程序。

小智 5

如果应用程序无法访问 some_file_name.properties 文件，则会出现此问题。请确保属性文件位于 spring 的 resources 文件夹下。

故障排除步骤

1：在资源文件夹下添加属性文件。

2：如果你没有资源文件夹。通过右键单击项目“新建”>“源文件夹”导航“新建”来创建一个，将其命名为“资源”并将属性文件放在其下。

对于基于注释的实现

Add @PropertySource(ignoreResourceNotFound = true, value = "classpath:some_file_name.properties")//在使用占位符之前添加

例子：

作业1Controller.Java

@PropertySource(ignoreResourceNotFound = true, value = "classpath:assignment1.properties")
@RestController  
public class Assignment1Controller {

//  @Autowired
//  Assignment1Services assignment1Services;
    @Value("${app.title}")
    private String appTitle;
     @RequestMapping(value = "/hello")  
        public String getValues() {

          return appTitle;

        }  

}
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赋值1.属性

app.title=Learning Spring
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Spring引导无法解析字符串中的占位符 7
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