spring - 由 : java. lang.IllegalArgumentException 引起:无法解析值 'some.other.property' 中的占位符 "${some.other.property}"

Question

我是 Spring 技术的新手，这个问题已经困扰我几个小时了。我的 Spring Cloud 配置客户端无法从配置服务器读取属性，因为我收到 IllegalArgumentException。配置服务器显示所有属性，但我认为 propertySources 列表 中的 name 属性存在问题，我的疯狂猜测是这就是我遇到此问题的原因。我在这里附上源代码、错误和输出。请帮帮我!!

错误:

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.4.1)

2021-01-03 22:52:41.286  INFO 6124 --- [  restartedMain] c.e.c.ConfigClientAppApplication         : Starting ConfigClientAppApplication using Java 14.0.2 on RahulNair with PID 6124 (C:\Users\nairr\Documents\DB Learnings\Spring Apps\Spring Cloud\config-client-app\target\classes started by nairr in C:\Users\nairr\Documents\DB Learnings\Spring Apps\Spring Cloud\Spring_Cloud_And_Microservices)
2021-01-03 22:52:41.286  INFO 6124 --- [  restartedMain] c.e.c.ConfigClientAppApplication         : No active profile set, falling back to default profiles: default
2021-01-03 22:52:41.467  INFO 6124 --- [  restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
2021-01-03 22:52:41.467  INFO 6124 --- [  restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG'
2021-01-03 22:52:43.907  INFO 6124 --- [  restartedMain] o.s.cloud.context.scope.GenericScope     : BeanFactory id=ccf80bff-8490-3f1d-990f-4b6383bd7788
2021-01-03 22:52:44.391  INFO 6124 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 6451 (http)
2021-01-03 22:52:44.407  INFO 6124 --- [  restartedMain] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2021-01-03 22:52:44.407  INFO 6124 --- [  restartedMain] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.41]
2021-01-03 22:52:44.548  INFO 6124 --- [  restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2021-01-03 22:52:44.548  INFO 6124 --- [  restartedMain] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 3081 ms
2021-01-03 22:52:45.038  INFO 6124 --- [  restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor  : Initializing ExecutorService 'applicationTaskExecutor'
2021-01-03 22:52:45.471  INFO 6124 --- [  restartedMain] o.s.b.d.a.OptionalLiveReloadServer       : LiveReload server is running on port 35729
2021-01-03 22:52:45.647  INFO 6124 --- [  restartedMain] o.s.b.a.e.web.EndpointLinksResolver      : Exposing 15 endpoint(s) beneath base path '/actuator'
2021-01-03 22:52:45.723  INFO 6124 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 6451 (http) with context path ''
2021-01-03 22:52:45.833  WARN 6124 --- [  restartedMain] ConfigServletWebServerApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.configClientController': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'some.other.property' in value "${some.other.property}"
2021-01-03 22:52:45.836  INFO 6124 --- [  restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'
2021-01-03 22:52:45.853  INFO 6124 --- [  restartedMain] o.apache.catalina.core.StandardService   : Stopping service [Tomcat]
2021-01-03 22:52:45.877  INFO 6124 --- [  restartedMain] ConditionEvaluationReportLoggingListener : 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2021-01-03 22:52:45.908 ERROR 6124 --- [  restartedMain] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.configClientController': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'some.other.property' in value "${some.other.property}"
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:405) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1415) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:608) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:531) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$1(AbstractBeanFactory.java:374) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.cloud.context.scope.GenericScope$BeanLifecycleWrapper.getBean(GenericScope.java:381) ~[spring-cloud-context-3.0.0.jar:3.0.0]
    at org.springframework.cloud.context.scope.GenericScope.get(GenericScope.java:184) ~[spring-cloud-context-3.0.0.jar:3.0.0]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:371) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1159) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.cloud.context.scope.refresh.RefreshScope.eagerlyInitialize(RefreshScope.java:124) ~[spring-cloud-context-3.0.0.jar:3.0.0]
    at org.springframework.cloud.context.scope.refresh.RefreshScope.start(RefreshScope.java:116) ~[spring-cloud-context-3.0.0.jar:3.0.0]
    at org.springframework.cloud.context.scope.refresh.RefreshScope.onApplicationEvent(RefreshScope.java:111) ~[spring-cloud-context-3.0.0.jar:3.0.0]
    at org.springframework.cloud.context.scope.refresh.RefreshScope.onApplicationEvent(RefreshScope.java:66) ~[spring-cloud-context-3.0.0.jar:3.0.0]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:426) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:383) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:943) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:591) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:144) ~[spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:767) ~[spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) ~[spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:426) ~[spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:326) ~[spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1309) ~[spring-boot-2.4.1.jar:2.4.1]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1298) ~[spring-boot-2.4.1.jar:2.4.1]
    at com.example.configclientapp.ConfigClientAppApplication.main(ConfigClientAppApplication.java:12) ~[classes/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) ~[spring-boot-devtools-2.4.1.jar:2.4.1]
Caused by: java.lang.IllegalArgumentException: Could not resolve placeholder 'some.other.property' in value "${some.other.property}"
    at org.springframework.util.PropertyPlaceholderHelper.parseStringValue(PropertyPlaceholderHelper.java:178) ~[spring-core-5.3.2.jar:5.3.2]
    at org.springframework.util.PropertyPlaceholderHelper.replacePlaceholders(PropertyPlaceholderHelper.java:124) ~[spring-core-5.3.2.jar:5.3.2]
    at org.springframework.core.env.AbstractPropertyResolver.doResolvePlaceholders(AbstractPropertyResolver.java:239) ~[spring-core-5.3.2.jar:5.3.2]
    at org.springframework.core.env.AbstractPropertyResolver.resolveRequiredPlaceholders(AbstractPropertyResolver.java:210) ~[spring-core-5.3.2.jar:5.3.2]
    at org.springframework.context.support.PropertySourcesPlaceholderConfigurer.lambda$processProperties$0(PropertySourcesPlaceholderConfigurer.java:175) ~[spring-context-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveEmbeddedValue(AbstractBeanFactory.java:931) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1308) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1287) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:119) ~[spring-beans-5.3.2.jar:5.3.2]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:399) ~[spring-beans-5.3.2.jar:5.3.2]
    ... 33 common frames omitted


Process finished with exit code 0

当我点击 Spring Cloud 配置服务器的 ./{config-client-name}/{client-profile} 端点时，我得到以下输出。我认为有问题的部分以黄色突出显示。

Spring Cloud Config Server Output Image

以下是我的配置服务器代码

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>config-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>config-server</name>
    <description>Demo project for Spring cloud</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>2020.0.0</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
                <includes>
                    <include>**/*.properties</include>
                </includes>
            </resource>
        </resources>
    </build>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>

</project>

application.properties

spring.application.name=config-server
server.port=8888
spring.cloud.config.server.git.uri=https://github.com/rahul976451/config-server-props.git

JAVA代码

package com.example.configserver;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.config.server.EnableConfigServer;

@SpringBootApplication
@EnableConfigServer
public class ConfigServerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConfigServerApplication.class, args);
    }

}

以下是我的配置客户端代码

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.1</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>config-client-app</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>config-client-app</name>
    <description>Demo project for Spring cloud</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>2020.0.0</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-client</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
                <includes>
                    <include>**/*.properties</include>
                </includes>
            </resource>
        </resources>
    </build>

    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </repository>
    </repositories>

</project>

application.properties 文件

server.port=6451
management.endpoints.web.exposure.include=*

bootstrap.properties 文件

spring.application.name=config-client-app
spring.cloud.config.uri=http://localhost:8888
eureka.client.server-url.defaultZone=http://localhost:8761/eureka/

JAVA代码ma​​in.java

package com.example.configclientapp;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class ConfigClientAppApplication {

    public static void main(String[] args) {
        SpringApplication.run(ConfigClientAppApplication.class, args);
    }

}

ConfigClientAppConfiguration.java

package com.example.configclientapp;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@Component
@ConfigurationProperties(prefix ="some") //Going to represent our property that is named some.property
public class ConfigClientAppConfiguration {

    private String property;

    public String getProperty() {
        return property;
    }

    public void setProperty(String property) {
        this.property = property;
    }
}

ConfigClientController.java

package com.example.configclientapp;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RefreshScope
public class ConfigClientController {
    @Autowired
    private ConfigClientAppConfiguration properties;

    @Value("${some.other.property}") //from the configuration server's application.properties file
    private String someOtherProperty;

    @RequestMapping("/")
    public String printConfig(){
        StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append(properties.getProperty());
        stringBuilder.append(" || ");
        stringBuilder.append(someOtherProperty);
        return stringBuilder.toString();
    }
}

抱歉，如果我有任何愚蠢的错误，请指出。谢谢!

Answer 1

“${some.other.property}”正在尝试在 application.properties 文件中搜索该属性，并尝试将其值注入(inject)到 someOtherProperty 变量中，正如这部分代码所预期的那样:

 @Value("${some.other.property}") //from the configuration server's application.properties file
    private String someOtherProperty;

查看您的 application.properties 文件，很明显没有定义名为 some.other.property 的此类条目。问题就在这里，Spring 正在尝试注入(inject)一个不存在于此类文件中的值。