mapping values are not allowed here

造成该错误的原因呢，我这里是因为spring boot配置文件中格式问题

## 避免和 server 工程端口冲突
server.port=8080

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/read_data?useUnicode=true&characterEncoding=UTF-8&useSSL=false
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver

我修改成如下就正常了

## 避免和 server 工程端口冲突
server:
  port: 8080

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/read_data?useUnicode=true&characterEncoding=UTF-8&useSSL=false
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver