spring boot启动时加载外部配置文件的方法

@SpringBootApplication
public class Application {

 public static void main(String[] args) throws Exception {
  SpringApplicationBuilder springApplicationBuilder = new SpringApplicationBuilder(Application.class);
  springApplicationBuilder.web(true);
  Properties properties = getProperties();
  StandardEnvironment environment = new StandardEnvironment();
  environment.getPropertySources().addLast(new PropertiesPropertySource("micro-service", properties));
  springApplicationBuilder.environment(environment);
  springApplicationBuilder.run(args);
 }

 private static Properties getProperties() throws IOException {
  PropertiesFactoryBean propertiesFactoryBean = new PropertiesFactoryBean();
  ResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
  propertiesFactoryBean.setIgnoreResourceNotFound(true);
  Resource fileSystemResource = resolver.getResource("file:/opt/company/test.properties");
  propertiesFactoryBean.setLocations(fileSystemResource);
  propertiesFactoryBean.afterPropertiesSet();
  return propertiesFactoryBean.getObject();
 }
}

@Component
public class EnvironmentUtil {
 private static Environment environment;
 @Autowired
 public void setEnvironment(Environment environment) {
  EnvironmentUtil.environment = environment;
 }

 public static <T> T getProperty(String key, Class<T> targetType, T defaultValue) {
  return environment.getProperty(key, targetType, defaultValue);
 }

 public static <T> T getProperty(String key, Class<T> targetType) {
  return environment.getProperty(key, targetType);
 }

 public static String getProperty(String key) {
  return environment.getProperty(key);
 }

 public static String getProperty(String key, String defaultValue) {
  return environment.getProperty(key, defaultValue);
 }

 public static Integer getInteger(String key, Integer defaultValue) {
  return environment.getProperty(key, Integer.class, defaultValue);
 }
}