spring 静态变量注入

spring 中不支持直接进行静态变量值的注入，我们看一下代码：

@Component(value = "KafkaConfig")
@ConfigurationProperties(prefix = "baseConfig")
public class KafkaConfig {
private static String logBrokerList;

 public static String getLogBrokerList() {
    return logBrokerList;
 }

 public static void setLogBrokerList(String logBrokerList) {
    KafkaConfig.logBrokerList = logBrokerList;
 }
}

配置文件如下：

baseConfig:
  logBrokerList: 10.10.2.154:9092
  logTopic: test  
  monitorTopic: monitor  

项目启动时使用 logBrokerList变量

@SpringBootApplication
public class Application {
public  static void main(String[] args) throws Exception {
SpringApplication.run(Application.class, args);
System.out.println("config static test :" + KafkaConfig.getLogBrokerList());
}
}

执行结果：config static test ：null

---

解决办法

利用spring的set注入方法，通过非静态的setter方法注入静态变量
，我们可以改成这样就静态变量可以获取到你配置的信息了：

@Component(value = "KafkaConfig")
@ConfigurationProperties(prefix = "baseConfig")
public class KafkaConfig {
private static String logBrokerList;

public static String getLogBrokerList() {
return logBrokerList;
}
@Value("${baseConfig.logBrokerList}")
public  void setLogBrokerList(String logBrokerList) {
KafkaConfig.logBrokerList = logBrokerList;
}
}

执行结果：config static test :10.10.2.154:9092