在Spring Cloud中使用@RefreshScope重新加载Spring属性时出错

Question

I'm testing one prototype for spring-cloud using @RefreshScope annotation. I'm using one external property file for that. Which I have provided and configured in runtime argument.

pom.xml dependency

<?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      http://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>2.1.1.RELEASE</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>com.proto.reload</groupId>
<artifactId>CachingService</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>CachingService</name>
<description>Demo project for cache</description>

<properties>
    <java.version>1.8</java.version>
</properties>

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

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-context</artifactId>
        <version>1.1.8.RELEASE</version>
    </dependency>

    <!-- <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-config-client</artifactId> 
        <version>1.1.3.RELEASE</version> </dependency> -->
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

This is main class

package com.proto.reload;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.context.ApplicationPidFileWriter;

@SpringBootApplication
public class CachingServiceApplication {

public static void main(String[] args) {
    if (args.length == 0) {
        System.out.println("Invalid Commandline argument. Please provide Consumer Properties file.");
        System.exit(0);
    }
    new SpringApplicationBuilder(CachingServiceApplication.class)
            .listeners(new ApplicationPidFileWriter())
            .properties("spring.config.name:" + args[0].replaceAll(".properties", ""))
            .build()
            .run(args);

    while (true) {
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        System.out.println(ConfigClass.getName());
    }
}

}

Config class having @RefreshScope annotation

package com.proto.reload;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.context.annotation.Configuration;

@Configuration
@RefreshScope
public class ConfigClass {

    private static String name;

    public static String getName() {
        return name;
    }

    @Value("${app.prop.name}")
    public void setName(String name) {
        this.name = name;
    }

}

And this is property file I'm passing through argument

app.prop.name=FirstOldValue

spring.pid.file=TestOne.pid

When I run this code, I get the following error.

   12:38:41.051 [main] DEBUG org.springframework.boot.context.logging.ClasspathLoggingApplicationListener - Application failed to start with classpath: [file:/C:/Program%20Files/Java/jre1.8.0_191/lib/resources.jar, file:/C:/Program%20Files/Java/jre1.8.0_191/lib/rt.jar, file:/C:/Program%20Files/Java/jre1.8.0_191/lib/jsse.jar, file:/C:/Program%20Files/Java/jre1.8.0_191/lib/jce.jar, file:/C:/Program%20Files/Java/jre1.8.0_191/lib/charsets.jar, file:/C:/Program%20Files/Java/jre1.8.0_191/lib/jfr.jar, file:/C:/Program%20Files/Java/jre1.8.0_191/lib/ext/access-bridge-64.jar, file:/C:/Program%20Files/Java/jre1.8.0_191/lib/ext/cldrdata.jar, ...]
12:38:41.105 [main] ERROR org.springframework.boot.SpringApplication - Application run failed
java.lang.NoSuchMethodError: org.springframework.boot.builder.SpringApplicationBuilder.<init>([Ljava/lang/Object;)V
    at org.springframework.cloud.bootstrap.BootstrapApplicationListener.bootstrapServiceContext(BootstrapApplicationListener.java:120)
    at org.springframework.cloud.bootstrap.BootstrapApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:84)
    at org.springframework.cloud.bootstrap.BootstrapApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:62)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127)
    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:75)
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54)
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:347)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:306)
    at com.proto.reload.CachingServiceApplication.main(CachingServiceApplication.java:19)

Am I using @RefreshScope in wrong way ? This code works fine when I remove dependency and @RefreshScope, but its not updating property value at runtime. My goal is to load modified property value at runtime.

Answer 1

1.1.8.RELEASE for Spring Cloud is part of the Camden Release train which is for Spring Boot 1.4.x releases.

Please see the Release Trains section for what release train to use for your Spring Boot version

https://spring.io/projects/spring-cloud

Currently they are,

Release Train Boot Version

Greenwich 2.1.x

Finchley 2.0.x

Edgware 1.5.x

Dalston 1.5.x

As your using spring boot 2.1.1 your dependency management should look like the below, note as Greenwich doesn't have a RELEASE yet you need to add the milestone repository.

 <repositories>
    <repository>
        <id>spring-milestones</id>
        <name>Spring Milestones</name>
        <url>http://repo.spring.io/milestone</url>
        <snapshots>
            <enabled>false</enabled>
        </snapshots>
    </repository>
</repositories>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>Greenwich.RC2</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-context</artifactId>
    </dependency>

</dependencies>

Answer 2

Add cloud context depedency and try again

<dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-context</artifactId>
        <version>1.1.8.RELEASE</version>
    </dependency>

Update : it is just not a valid use case to have @Configuration and @RefreshScope on the same element. As per this URL thread : https://github.com/spring-cloud/spring-cloud-config/issues/43