I encountered an issue where, when using Apollo to inject a static variable property, the variable is null during project startup. However, when the variable is modified via Apollo, its value is displayed correctly. The code is roughly as follows.

@Service
public class ApolloServiceImpl implements ApolloService {
    @Value("${acc.clean.apollo.loading.num:10}")
    private static Long apollo_num ;
    @Value("${acc.clean.apollo.loading.num:10}")
    private Long num1;

    @Override
    public String getApolloNum() {
        return "static value：" + apollo_num + " private value：" + num1;
    }
}

The execution result during project startup

static value：null private value：14

The execution result after modifying the data via Apollo

static value：17 private value：17

I understand that the way of injecting static variables in the code was incorrect and have already fixed it. However, I want to know the reason behind this phenomenon (the data being null during project startup but correct after modification). I suspect it's due to the order of configuration data loading.