问题描述
Spring Boot项目中运行之后,出现如下的错误:
*************************** APPLICATION FAILED TO START *************************** Description: Failed to configure a DataSource: ‘url‘ attribute is not specified and no embedded datasource could be configured. Reason: Failed to determine a suitable driver class Action: Consider the following: If you want an embedded database (H2, HSQL or Derby), please put it on the classpath. If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).
或者出现@Value注解的值无法导入的时候,
Could not resolve placeholder ‘elasticsearch.host‘ in value "${elasticsearch.host}"
可以用以下的解决方案
问题分析及解决方案
问题原因: Mybatis没有找到合适的加载类,其实是大部分spring - datasource - url没有加载成功,分析原因如下所示.
- DataSourceAutoConfiguration会自动加载.
- 没有配置spring - datasource - url 属性.
- spring - datasource - url 配置的地址格式有问题.
- 配置 spring - datasource - url的文件没有加载.
网上给出了这几种解决方案.
方案一 (解决原因1)
排除此类的autoconfig。启动以后就可以正常运行。
@SpringBootApplication(exclude= {DataSourceAutoConfiguration.class})
方案二 (解决原因2)
在application.properties/或者application.yml文件中没有添加数据库配置信息.
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
方案三 (解决原因3)
在spring xml配置文件中引用了数据库地址 所以需要对:等进行转义处理.但是在application.properties/或者application.yml文件并不需要转义,错误和正确方法写在下面了.
#错误示例 spring.datasource.url = jdbc:mysql\://192.168.0.20\:1504/f_me?setUnicode=true&characterEncoding=utf8 #正确示例 spring.datasource.url = jdbc:mysql://192.168.0.20:1504/f_me?setUnicode=true&char
方案四 (解决原因4)
要在pom文件中<build></build>添加如下.来保证yml或者properties文件能被正常扫描到且加载成功.(intellij idea 运行时,扫描不到src文件夹(java文件夹)里面的配置文件)
<resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.yml</include> <include>**/*.properties</include> </includes> <filtering>false</filtering> </resource> <resource> <directory>src/main/resources</directory> <includes> <include>**/*.yml</include> <include>**/*.properties</include> </includes> <filtering>false</filtering> </resource> </resources>
原文地址:https://www.cnblogs.com/phlive/p/11459147.html
时间: 2024-11-13 10:03:47