记一次笔记：ComponentScan指定扫描包，导致默认包扫描器失效

迈不过友情╰ 2023-09-27 10:52 149阅读 0赞

springboot启动类启动时，会默认扫描启动类所在的目录，在启动类上添加ComponentScan去指定扫描位置，从而可以扫多个包，尤其是第三方中的jar/maven依赖中的组件

但是，当指定扫描包后，原来的包默认扫描器会随之失效，如果不注意，会导致项目的组件没办法使用，如下：

![04fd13a214304a118daa8b0b7e644c74.png][]

当在启动类指定扫描第三方的组件包，如下：

>     package com.shuizhu;
>     
>     import org.springframework.boot.SpringApplication;
>     import org.springframework.boot.autoconfigure.SpringBootApplication;
>     import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
>     import org.springframework.context.annotation.ComponentScan;
>     
>     @ComponentScan(basePackages = {"com.thrid"})
>     @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
>     public class ShuizhuMultipleDsApplication {
>     
>         public static void main(String[] args) {
>             SpringApplication.run(ShuizhuMultipleDsApplication.class, args);
>         }
>     
>     }

我的controller层有个接口吗，如下：

package com.shuizhu.controller;
    
    import com.bosera.dw.commons.controller.BaseCtrl;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    /**
     * @author 睡竹
     * @date 2022/9/20
     */
    @RestController
    public class TestController {
        @GetMapping("/test")
        public String test(){
            return "success";
        }
    }

**当访问该接口时，会报404**

还需要在启动类上，添加当前项目的包位置，如下：

>     package com.shuizhu;
>     
>     import org.springframework.boot.SpringApplication;
>     import org.springframework.boot.autoconfigure.SpringBootApplication;
>     import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
>     import org.springframework.context.annotation.ComponentScan;
>     
>     @ComponentScan(basePackages = {"com.thrid","com.shuizhu"})
>     @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
>     public class ShuizhuMultipleDsApplication {
>     
>         public static void main(String[] args) {
>             SpringApplication.run(ShuizhuMultipleDsApplication.class, args);
>         }
>     
>     }

[04fd13a214304a118daa8b0b7e644c74.png]: https://img-blog.csdnimg.cn/04fd13a214304a118daa8b0b7e644c74.png