springboot yml定义属性,下文中${} 引用说明

application.yml
spring:
 datasource:
  driver-class-name: com.mysql.cj.jdbc.Driver
  url: jdbc:mysql://172.16.126.135:3306/emall?characterEncoding=utf-8
  username: watson.wei
  password: Password123#

import lombok.Getter;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
 
@Component
@Getter
public class YamlUtil {
  // 【注】@Value("${prefix_name}")注解的变量不能是static或final，否则yamlUtil获取的值为null
  @Value("${spring.datasource.url}")
  private String datasourceUrl;
 
  @Value("${spring.datasource.username}")
  private String datasourceUsername;
 
  @Value("${spring.datasource.password}")
  private String datasourcePassword;
}

import com.demo.shiro.util.YamlUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
@Service
@Slf4j
public class YamlTest {
  // 【注】不能使用new YamlUtil()来创建对象，否则yamlUtil获取的值为null
  @Autowired
  private YamlUtil yamlUtil;
 
  public void test() {
    log.info(yamlUtil.getDatasourcePassword());
  }
}