The issue of Spring Boot not loading the NacosConfigBootstrapConfiguration class often arises due to misconfigurations or compatibility issues between Spring Boot and Nacos. Here are the main reasons and solutions:
1. Spring Boot Version and Nacos Spring Boot Starter Version Mismatch
The NacosConfigBootstrapConfiguration class is part of the spring-cloud-alibaba or nacos-spring-boot dependencies. If there is a version mismatch between Spring Boot and the Nacos starter, the class may not be loaded.
Solution:
- Check your Spring Boot version.
- Ensure that the version of
spring-cloud-alibabaornacos-spring-bootyou are using is compatible with your Spring Boot version.
For example:
- For Spring Boot 2.3.x , use
spring-cloud-alibaba 2.2.x.RELEASE. - For Spring Boot 2.5.x , use
spring-cloud-alibaba 2021.x.
Refer to the official compatibility table for accurate version mappings.
2. Spring Boot Changed the Bootstrap Context in 2.4.x
Starting with Spring Boot 2.4 , the bootstrap.properties or bootstrap.yml mechanism was replaced by the spring.config.import property. If you're using a version after Spring Boot 2.4.x, the configuration loading behavior has changed, and you might need to adjust your configuration files.
Solution:
- Migrate from
bootstrap.ymltoapplication.yml. - Use
spring.config.import=nacos:to explicitly define Nacos configuration.
Example:
spring: config: import: nacos://localhost:8848 nacos: config: server-addr: localhost:8848
3. Nacos Dependencies Missing in Classpath
If the NacosConfigBootstrapConfiguration class is not in your project, it might be due to missing or incorrectly included dependencies.
Solution:
Ensure you have the correct dependencies in your pom.xml (for Maven) or build.gradle (for Gradle).
For Maven:
<dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId> <version>2021.0.4.0</version> </dependency>
For Gradle:
implementation 'com.alibaba.cloud:spring-cloud-starter-alibaba-nacos-config:2021.0.4.0'
4. Incorrect Configuration in application.yml or bootstrap.yml
If the server-addr or other required properties are not specified correctly, Nacos will fail to initialize.
Solution:
Ensure your configuration file includes the necessary properties:
spring: cloud: nacos: config: server-addr: localhost:8848
5. Nacos Configuration Not Activated
If the application profile or configuration is not correctly set up, the Nacos configuration may not be activated.
Solution:
- Ensure you have the correct Spring profiles (
application.propertiesorapplication.yml) activated. - Check for
spring.profiles.activein your configurations.
Debugging Steps
- Check Logs: Look for any errors or warnings during application startup that reference Nacos configuration.
- Enable Debug Logging : Add
-Dlogging.level.com.alibaba.nacos=DEBUGto the JVM arguments to see detailed logs for Nacos. - Validate Dependencies : Use tools like
mvn dependency:treeto ensure the required dependencies are correctly resolved.