Question

1. 数据库连接失败

Failed to configure a DataSource

检查application.properties中的数据库URL、用户、密码，或排除数据源配置：

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})

2. Bean依赖缺失

No qualifying bean of type 'X' available

确保依赖的类已被Spring管理（添加@Component、@Service等注解）或正确配置Bean方法

3. 端口占用

Web server failed to start.Port 8080...

更换端口：server.port=8081或终止占用端口的进程

4. 配置文件错误

Could not resolve placeholder 'xxx'

检查application.properties中的属性拼写，或确保@Value注入的健值存在

5. 依赖冲突/缺失

ClassNotFoundException/NoClassDefFoundError

检查pom.xml或build.gradle，确保依赖项完整且版本兼容

6. 循环依赖

Requested bean is currently in creation

使用构造器注入替代字段注入，或用@Lazy延迟加载