application.properties 文件和 application.yml 文件的区别

yml文件的好处，天然的树状结构，方便查看，最终会转成application.properties

注意点：

1，原有的key，例如spring.jpa.properties.hibernate.dialect，按“.”分割，都变成树状的配置

2，key后面的冒号，后面一定要跟一个空格

3，把原有的application.properties删掉。然后一定要执行一下  maven -X clean instal

#application.yml
 
server:
  port: 8080
  
spring:
    datasource:
        name: test
        url: jdbc:mysql://127.0.0.1:3306/test
        username: root
        password: xxx
        # 使用druid数据源
        type: com.alibaba.druid.pool.DruidDataSource
        driver-class-name: com.mysql.jdbc.Driver
        filters: stat
        maxActive: 20
        initialSize: 1
        maxWait: 60000
        minIdle: 1
        timeBetweenEvictionRunsMillis: 60000
        minEvictableIdleTimeMillis: 300000
        validationQuery: select 'x'
        testWhileIdle: true
        testOnBorrow: false
        testOnReturn: false
        poolPreparedStatements: true
        maxOpenPreparedStatements: 20