application.yml)

　　使用springboot默认创建项目，是application.properties,改成yml格式时，需要注意以下几点：

注释中不能用中文
yml格式，采用tree形状，key和value中的“冒号",冒号与值之间要有空格，如 username: root
同一级别节点格式要对齐,下面红包部分由于没有对齐，运行项目时报错

spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/business?useUnicode=true&characterEncoding=utf-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
    username: root
     password: root
    driverClassName: com.mysql.cj.jdbc.Driver
    # use mysql
  jpa:
    database: mysql
      # is show  sql
    show-sql: true
mybatis:
  typeAliasesPackage: com.xj.demo.model
  mapper-locations: classpath:mapper/*.xml
# JWT Object save audience
audience:
    clientId: 098f6bcd4621d373cade4e832627b4f6
    # A key that can be replaced by Base64 encryption
    base64Secret: MDk4ZjZiY2Q0NjIxZDM3M2NhZGU0ZTgzMjYyN2I0ZjY=
    # The issuing subject of the JWT shall be deposited in the issuer
    name: springbootapi
    # Expired 24 hours
    expiresSecond: 86400

pagehelper:
    helperDialect: mysql
    reasonable: true  # To minimize or maximize the number of pages when the input page is negative or larger
    supportMethodsArguments: true
    params: count:countSql

　　yml中格式错误，肉眼不太容易找出错误，推荐一个在线查看的工具：http://old.qqe2.com/jsontool/yaml.php