【DEBUG】Error starting ApplicationContext. To display the conditions report re-run your application w

BUG INFO

本项目源自《尚硅谷SpringBoot核心技术篇 —— springboot-data-jdbc-demo》

根据application.yml自动加载配置department.sql和employee.sql时的报错信息

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-03-09 11:30:11.671 ERROR 30260 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

***************************
APPLICATION FAILED TO START
***************************

Description:

Binding to target [[email protected] type = java.util.List<java.lang.String>, value = 'provided', annotations = array<Annotation>[[empty]]] failed:

    Property: spring.datasource.schema[0].classpath
    Value: sql/department.sql
    Origin: class path resource [application.yml]:8:20
    Reason: The elements [spring.datasource.schema[0].classpath,spring.datasource.schema[1].classpath] were left unbound.
    Property: spring.datasource.schema[1].classpath
    Value: sql/employee.sql
    Origin: class path resource [application.yml]:9:20
    Reason: The elements [spring.datasource.schema[0].classpath,spring.datasource.schema[1].classpath] were left unbound.

Action:

Update your application's configuration


Process finished with exit code 1

BUG分析

• application.yml配置

  spring:
    datasource:
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://192.168.137.130:3306/jdbc?serviceTimezone=UTC
      username: root
      password: xxxxxx
  

• 添加schema之前，运行 SpringbootDataJdbcDemoApplicationTests.java 看到自己的默认数据源是HikariDatasource ，课程中的则是来自Tomcat 。

  class com.zaxxer.hikari.HikariDataSource
  [email protected] wrapping [email protected]
  

  同样可以切换其他数据源，如配置Druid阿里巴巴数据源

• 添加指定位置的sql文件配置

  schema:
    - classpath: sql/department.sql
    - classpath: sql/employee.sql
  

• 结果出现了上述的DUG INFO

  Reason: The elements [spring.datasource.schema[0].classpath,spring.datasource.schema[1].classpath] were left unbound.
  

  因为我们配置的schema是List<String>类型，而且List内存放的是String 类型数据，提示元素信息未绑定，是因为在配置的时候，冒号两侧加了空格，导致识别不了此路径下的sql文件 。

  schema[0] 即classpath:sql/department.sql

  schema[1] 即classpath:sql/employee.sql

  private List<String> schema;
  

DEBUG方案

• 配置spring.datasource.schema时，schema内的元素是Spring类型，classpath冒号两侧不可添加空格

• 在以上步骤完成后，解决了报错问题，但是，无报错信息，建表还是未成功啊！

• 查阅相关文档后，给出以下解决方案：

  • 添加spring.datasource.initialization-mode: always

    spring:
      datasource:
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://192.168.137.130:3306/jdbc?serviceTimezone=UTC
        username: root
        password: xxxxxx
        schema:
          - classpath:sql/department.sql
          - classpath:sql/employee.sql
        type: com.alibaba.druid.pool.DruidDataSource
        initialization-mode: always
    

• 至此，完美解决！