算是很全各种方式啦，就看哪种最适合在项目使用了

第一种方式，从 Authentication 获取

@RestController
public class IndexController {

    @GetMapping("/no-public/user-info")
    String getUserInfo(
            Authentication authentication
    ) {
        return authentication.getName();
    }
}

设置登录态的时候，填充到 principal 的是 MimeayDetail 类，在使用的时候可以将 authentication.getPrincipal() 转成 MimeayDetail

@RestController
public class IndexController {

    @GetMapping("/no-public/user-info")
    MimeayDetail getUserInfo(
            Authentication authentication
    ) {
        MimeayDetail mimeayDetail = (MimeayDetail) authentication.getPrincipal();
        return mimeayDetail;
    }
}

第二种方式, 从 Principal 获取

@RestController
public class IndexController {
    
    @GetMapping("/no-public/user-info")
    String getUserInfo(
            Principal principal
    ) {
        return principal.getName();
    }
}

第三种方式, 从自定义的用户类取

取整个自定义用户实体

@RestController
public class IndexController {

    @GetMapping("/no-public/user-info")
    MimeayDetail getUserInfo(
            @AuthenticationPrincipal MimeayDetail mimeayDetail
    ) {
        return mimeayDetail;
    }
}

自定义用户类内容

{
  "id": 1,
  "nickname": "chenxiaochi"
}

取自定义用户实体某个字段

public class IndexController {

    @GetMapping("/no-public/user-info")
    String getUserInfo(
            @AuthenticationPrincipal(expression = "nickname") String nickname
    ) {
        return nickname;
    }
}

查阅文档的时候，有一个做法也还不错，不想在程序中使用 AuthenticationPrincipal， 则可以在包装一层

@Target({ElementType.TYPE, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@AuthenticationPrincipal
public @interface MimeayUserDetail {
}

使用的时候就变成这样

@RestController
public class IndexController {

    @GetMapping("/no-public/user-info")
    MimeayDetail getUserInfo(
            @MimeayUserDetail MimeayDetail mimeayDetail
            ) {
        return mimeayDetail;
    }
}

其他方式

从 CurrentSecurityContext 获取

@RestController
public class IndexController {

    @GetMapping("/no-public/user-info")
    String getUserInfo(
           @CurrentSecurityContext(expression = "authentication") Authentication authentication
    ) {
        return authentication.getName();
    }
}

从 SecurityContextHolder 获取

@RestController
public class IndexController {

    @GetMapping("/no-public/user-info")
    MimeayDetail getUserInfo(
    ) {
        MimeayDetail mimeayDetail = (MimeayDetail) SecurityContextHolder.getContext().getAuthentication().getPrincipal();
        return mimeayDetail;
    }
}

可运行 demo

https://github.com/imeay/mimeay_security

参考文章

https://www.springcloud.io/post/2022-02/spring-security-get-current-user/#gsc.tab=0
https://www.baeldung.com/get-user-in-spring-security