@Configuration
public class ConfigByValueAnnotation {

    @Value("${server.port}")
    private String serverPort;

    public String getServerPort() {
        return serverPort;
    }
}

@DisplayName("multipart get config")
@SpringBootTest
public class MultipartGetConfigTest {

    private static final Logger log = LoggerFactory.getLogger(MultipartGetConfigTest.class);

    @Autowired
    private ConfigByValueAnnotation configByValueAnnotation;

    @Test
    public void getByValueAnnotation(){
        log.info("get by @Value, value: {}", configByValueAnnotation.getServerPort());
    }
}

@Component
@ConfigurationProperties(prefix = "server", ignoreInvalidFields = true)
public class ConfigByConfigurationProperties {

    private Integer port;

    public Integer getPort() {
        return port;
    }

    public ConfigByConfigurationProperties setPort(Integer port) {
        this.port = port;
        return this;
    }
}

@Configuration
public class ConfigByConfigurationPropertiesV2 {

    @Bean("configByValueAnnotationV2")
    @ConfigurationProperties(prefix = "server2")
    public Properties properties(){
        return new Properties();
    }

}

@DisplayName("multipart get config")
@SpringBootTest
public class MultipartGetConfigTest {

       private static final Logger log = LoggerFactory.getLogger(MultipartGetConfigTest.class);
    
       @Autowired
       private ConfigByConfigurationProperties configByConfigurationProperties;
    
       @Autowired
       @Qualifier("configByValueAnnotationV2")
       private Properties properties;
    
       @Test
       public void getByConfigurationProperties(){
           log.info("get by @ConfigurationProperties, value: {}", configByConfigurationProperties.getPort());
           log.info("get by @ConfigurationProperties and manual create bean, value: {}", properties.getProperty("port"));
       }

}

@Component
public class ConfigByEnvironment implements EnvironmentAware {

  private static final Logger log = LoggerFactory.getLogger(ConfigByEnvironment.class);
 
  private Environment environment;
 
  public Optional<String> get(String configKey){
      String config = environment.getProperty(configKey);
      return Objects.isNull(config) ? Optional.empty() : Optional.of(config);
  }
 
  public void get(String configKey, Consumer<String> consumer){
      Optional<String> config = get(configKey);
      if(!config.isPresent()){
          log.warn("application config, get config by key fail, key: {}", configKey);
      }
      config.ifPresent(consumer);
  }
 
  @Override
  public void setEnvironment(@NonNull Environment environment) {
      this.environment = environment;
  }
}

public enum ConfigByEnvironmentKey {

  SERVER_PORT("server.port", "server port");
 
  private String key;
 
  private String description;
 
  ConfigByEnvironmentKey(String key, String description) {
      this.key = key;
      this.description = description;
  }
 
  public String getKey() {
      return key;
  }
 
  public String getDescription() {
      return description;
  }
}

@DisplayName("multipart get config")
   @SpringBootTest
   public class MultipartGetConfigTest {

       private static final Logger log = LoggerFactory.getLogger(MultipartGetConfigTest.class);
    
       @Autowired
       private ConfigByEnvironment configByEnvironment;
    
       @Test
       public void getByEnvironment(){
           configByEnvironment.get(ConfigByEnvironmentKey.SERVER_PORT.getKey()).ifPresent(value -> log.info("get by environment, value: {}", value));
       }

}