Java 无法解析字符串值中的占位符
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Could not resolve placeholder in string value
提问by Hwen
I am trying to use properties from a .propertiesfile, but it doesn't seem to work.
我正在尝试使用.properties文件中的属性，但它似乎不起作用。
Here is my code:
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;
[...]
}
This class uses @Valueannotations to get the properties.
It is also declared as a Spring Service and is linked to my infraContext.xmlfile :
这个类使用@Value注释来获取属性。它也被声明为 Spring 服务并链接到我的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>
Using context:property-placeholder, I link this file to my context-core.propertiesfile :
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/
This does make sense, right ?
这确实有道理，对吧？
But when I try to launch my project, Tomcat throw this exception :
但是当我尝试启动我的项目时，Tomcat 抛出此异常：
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.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.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$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:485)
... 29 more
Or, in short : java.lang.IllegalArgumentException: Could not resolve placeholder 'project.ftp.adresse' in string value "${project.ftp.adresse}"
或者，简而言之： java.lang.IllegalArgumentException: Could not resolve placeholder 'project.ftp.adresse' in string value "${project.ftp.adresse}"
EDIT :
编辑 ：
Here is my web.xml :
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>
My infraContext.xml is imported in another .xml file named applicationContext.xml :
我的 infraContext.xml 被导入到另一个名为 applicationContext.xml 的 .xml 文件中：
<?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>
I am obviously missing something, but I can't figure out what.
我显然错过了一些东西，但我无法弄清楚是什么。
Please let me know if you need more details, as it is my first question here, I'll try to answer as soon as I can :).
如果您需要更多详细信息，请告诉我，因为这是我在这里的第一个问题，我会尽快回答:)。
采纳答案by M. Deinum
In your configuration you have 2 PropertySourcesPlaceholderConfigurerinstances.
在您的配置中，您有 2 个PropertySourcesPlaceholderConfigurer实例。
applicationContext.xml
应用上下文.xml
<bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
<property name="environment">
<bean class="org.springframework.web.context.support.StandardServletEnvironment"/>
</property>
</bean>
infraContext.xml
基础上下文.xml
<context:property-placeholder location="classpath:context-core.properties"/>
By default a PlaceholderConfigureris going to fail-fast, so if a placeholder cannot be resolved it will throw an exception. The instance from the applicationContext.xmlfile has no properties and as such will fail on all placeholders.
默认情况下 aPlaceholderConfigurer会快速失败，因此如果无法解析占位符，它将抛出异常。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。
Solution: Remove the one from applicationContext.xmlas it doesn't add anything it only breaks things.
解决方案：从applicationContext.xml 中删除一个，因为它没有添加任何东西，它只会破坏一些东西。
回答by user2910552
I had the same problem, resolved it by adding
我遇到了同样的问题，通过添加解决了它
<filtering>true</filtering>
in pom.xml :
在 pom.xml 中：
before (didn't work):
之前（不起作用）：
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
</resource>
</resources>
</build>
after(it worked):
之后（它有效）：
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
After that you just run mvn clean installand deploy application.
之后，您只需运行mvn clean install并部署应用程序。
回答by Gani
This Issue occurs if the application is unable to access the some_file_name.properties file.Make sure that the properties file is placed under resources folder in spring.
如果应用程序无法访问 some_file_name.properties 文件，则会出现此问题。请确保在 spring 中将属性文件放置在资源文件夹下。
Trouble shooting Steps
故障排除步骤
1: Add the properties file under the resource folder.
1：在资源文件夹下添加属性文件。
2: If you don't have a resource folder. Create one by navigating new by Right click on the project new > Source Folder, name it as resource and place your properties file under it.
2：如果你没有资源文件夹。右键单击新建项目> 源文件夹，将其命名为资源并将您的属性文件放在其下。
For annotation based Implementation
对于基于注解的实现
Add @PropertySource(ignoreResourceNotFound = true, value = "classpath:some_file_name.properties")//Add it before using the place holder
添加@PropertySource(ignoreResourceNotFound = true, value = "classpath:some_file_name.properties")//在使用占位符之前添加
Example:
例子：
Assignment1Controller.Java
Assignment1Controller.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;
}
}
assignment1.properties
assignment1.properties
app.title=Learning Spring
回答by Semir Delji?
In my case, I was careless while merging the application.yml file, and I've unnecessary indented my properties to the right.
就我而言，我在合并 application.yml 文件时粗心大意，并且我不必要地将我的属性缩进到右边。
I've indented it like this:
我是这样缩进的：
spring:
application:
name: applicationName
............................
myProperties:
property1: property1value
While the code expected it to be like this:
虽然代码期望它是这样的：
spring:
application:
name: applicationName
.............................
myProperties:
property1: property1value
回答by Ben G
My solution was to add a space between the $ and the {.
我的解决方案是在 $ 和 { 之间添加一个空格。
For example:
例如：
@Value("${project.ftp.adresse}")
becomes
变成
@Value("$ {project.ftp.adresse}")
回答by cdesmetz
With Spring Boot :
使用 Spring Boot：
In the pom.xml
在 pom.xml 中
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<addResources>true</addResources>
</configuration>
</plugin>
</plugins>
</build>
Example in class Java
Java 类中的示例
@Configuration
@Slf4j
public class MyAppConfig {
@Value("${foo}")
private String foo;
@Value("${bar}")
private String bar;
@Bean("foo")
public String foo() {
log.info("foo={}", foo);
return foo;
}
@Bean("bar")
public String bar() {
log.info("bar={}", bar);
return bar;
}
[ ... ]
In the properties files :
在属性文件中：
src/main/resources/application.properties
src/main/resources/application.properties
foo=all-env-foo
src/main/resources/application-rec.properties
src/main/resources/application-rec.properties
bar=rec-bar
src/main/resources/application-prod.properties
src/main/resources/application-prod.properties
bar=prod-bar
In the VM arguments of Application.java
在 Application.java 的 VM 参数中
-Dspring.profiles.active=[rec|prod]
Don't forget to run mvn command after modifying the properties !
修改属性后不要忘记运行 mvn 命令！
mvn clean package -Dmaven.test.skip=true
In the log file for -Dspring.profiles.active=rec :
在 -Dspring.profiles.active=rec 的日志文件中：
The following profiles are active: rec
foo=all-env-foo
bar=rec-bar
In the log file for -Dspring.profiles.active=prod :
在 -Dspring.profiles.active=prod 的日志文件中：
The following profiles are active: prod
foo=all-env-foo
bar=prod-bar
In the log file for -Dspring.profiles.active=local :
在 -Dspring.profiles.active=local 的日志文件中：
Could not resolve placeholder 'bar' in value "${bar}"
Oups, I forget to create application-local.properties.
糟糕，我忘记创建 application-local.properties。
回答by akasha
You can also try default values. spring-value-annotation
您也可以尝试使用默认值。弹簧值注释
Default values can be provided for properties that might not be defined. In this example the value “some default” will be injected:
可以为可能未定义的属性提供默认值。在这个例子中，值“some default”将被注入：
@Value("${unknown.param:some default}")
private String someDefault;
If the same property is defined as a system property and in the properties file, then the system property would be applied.
如果在属性文件中将同一属性定义为系统属性，则将应用系统属性。
回答by Ankush Thakur
I got same error in my Micro-service, whenever you declare @Value annotation in program i.e @Value("${project.api.key}")
我在我的微服务中遇到同样的错误，每当你在程序中声明 @Value 注释时，即@Value("${project.api.key}")
make sure that your application.properties file with same values should not be blankproject.api.key= add some values
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:otherwise it will through error "Error creating bean with name 'ServiceFTP': Injection of autowired dependencies"
MostImp ：否则它将通过错误“创建名为'ServiceFTP'的bean时出错：注入自动装配的依赖项”
回答by Ankush Thakur
I got same error in my Micro-service, whenever you declare @Value annotation in program i.e @Value("${project.api.key}")
我在我的微服务中遇到同样的错误，每当你在程序中声明 @Value 注释时，即@Value("${project.api.key}")
make sure that your application.properties file with same values should not be blank project.api.key= add some values
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:otherwise it will throw error "Error creating bean with name 'ServiceFTP': Injection of autowired dependencies"
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”
回答by Renato Vasconcellos
Deleting or corrupting the pom.xml file can cause this error.
删除或损坏 pom.xml 文件可能会导致此错误。
