Integrating Nacos with Spring Boot: Features, Advantages, and Code Example

Spring Boot is a popular microservice framework, and Nacos is Alibaba's open‑source Naming Configuration Service focused on service discovery and configuration management, supporting Java, Go, Python, C#, C++ and other languages.

Core features include a dynamic configuration service that centralizes and externalizes environment settings, a service discovery and management component with DNS‑based and RPC‑based (Dubbo, gRPC) modes plus health checks, and a dynamic DNS service offering weighted routing, flexible load balancing, and simple internal DNS resolution.

Nacos 2.x optimizes the communication layer by adopting gRPC for long‑living connections, which reduces frequent polling, lowers JVM Full GC pressure, and introduces keepalive messages, faster TCP disconnect detection, reliable streaming push, mitigation of TIME_WAIT issues, and finer‑grained synchronization to lessen inter‑node traffic.

To integrate Nacos with Spring Boot, add the following Maven dependencies:

<dependency>
    <groupId>com.alibaba.boot</groupId>
    <artifactId>nacos-config-spring-boot-starter</artifactId>
    <version>0.2.1</version>
</dependency>
<dependency>
    <groupId>com.alibaba.boot</groupId>
    <artifactId>nacos-config-spring-boot-actuator</artifactId>
    <version>0.2.1</version>
</dependency>

Configure the Nacos server address in application.yaml:

nacos:
  config:
    server-addr: 127.0.0.1:8848

Use @NacosPropertySource on the main class to specify the dataId and enable auto‑refresh, and @NacosValue to inject configuration values dynamically:

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class, DataSourceTransactionManagerAutoConfiguration.class})
@NacosPropertySource(dataId = "bulking-nacos-example", autoRefreshed = true)
public class StartApplication {
    public static void main(String[] args) {
        SpringApplication.run(StartApplication.class, args);
    }
}

An example controller demonstrates retrieving a configuration value via @NacosValue and exposing it through a REST endpoint:

@Controller
@RequestMapping("config")
public class ConfigController {
    @NacosValue(value = "${useLocalCache}", autoRefreshed = true)
    private boolean useLocalCache;

    @RequestMapping(value = "/get", method = GET)
    @ResponseBody
    public boolean get() {
        return useLocalCache;
    }
}

Run the application; Nacos provides a web console at http://localhost:8848/nacos/#/login (default credentials: nacos/nacos) to manage configurations, add dynamic config items, and observe real‑time updates without restarting the service.

The sample project is available at https://github.com/aalansehaiyang/spring-boot-bulking (module spring-boot-bulking-naco).