ResponseBodyAdvice踩坑及解决

@RestControllerAdvice(basePackages = "com.alan.api.controller")
public class ApiResponseBodyAdvice implements ResponseBodyAdvice {
    static org.slf4j.Logger logger = LoggerFactory.getLogger("logback_api");
    @Override
    public boolean supports(MethodParameter returnType, Class converterType) {
        return (AnnotatedElementUtils.hasAnnotation(returnType.getContainingClass(), ResponseBody.class) ||
                returnType.hasMethodAnnotation(ResponseBody.class));
    }
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType,
                  Class selectedConverterType, ServerHttpRequest serverHttpRequest, ServerHttpResponse response) {
        HttpServletRequest request = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getRequest();
        if(request != null){
            Object obj = request.getSession().getAttribute(BaseController.session_user);
            String path = request.getServletPath();
            if (StringUtils.isBlank(path)) {
                path = request.getPathInfo();
            }
            if (obj != null) {
                path = request.getPathInfo();
                logger.info("userId:"+ ((DataUser) obj).getUserId());
            }
            logger.info("url:"+ path);
            logger.info("request:"+ JSON.toJSONString(request.getParameterMap()));
            logger.info("response:"+body);
        }
        return body;
    }
}

public interface ResponseBodyAdvice<T> { 
    / * *
    *该组件是否支持给定的控制器方法返回类型
    *和选择的{@code HttpMessageConverter}类型。
    返回类型
    * @param converterType选择的转换器类型
    * @return {@code true}如果{@link #beforeBodyWrite}应该被调用;
    * {@code false}否则
    * /
	boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType);
    / * *
    *在{@code HttpMessageConverter}被选中之后和之前调用
    *它的write方法被调用。
    * @param body要写入的主体
    控制器方法的返回类型：
    * @param selectedContentType通过内容协商选择的内容类型
    * @param selectedConverterType选择写入响应的转换器类型
    * @param request当前请求
    * @param response当前响应
    * @return传入的主体或修改过的(可能是新的)实例
   * /
	@Nullable
	T beforeBodyWrite(@Nullable T body, MethodParameter returnType, MediaType selectedContentType,
			Class<? extends HttpMessageConverter<?>> selectedConverterType,
			ServerHttpRequest request, ServerHttpResponse response);
}

@RestController //此注解包含@ResponseBody注解
@RequestMapping("/nandao")
public class ResponseBodyAdviceController {
 
    @RequestMapping(value = "/hello", method = RequestMethod.GET)
    public int hello() {
         //业务代码省略
        return 5;
    } 
}

/**
*此注解针对controller层的类做增强功能，即对加了@RestController注解的类进行处理
*/
@ControllerAdvice(annotations = RestController.class)
public class RestResultWrapper implements ResponseBodyAdvice<Object> {
    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return true;
    }
 
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request,
                                  ServerHttpResponse response) {
 
            //定义一个统一的返回类
            RestResult responseResult = new RestResult( "0", body, "success");
             //如果handler处理类的返回类型是String（即控制层的返回值类型），为了保证一致性，这里需要将ResponseResult转回去
            if(body instanceof String) {
                return JSON.toJSONString(responseResult);
            }
           //封装后的数据返回到前端页面
            return JSONObject.toJSON(responseResult);       
    } 
}

/**
 * @author nandao
 * Created on 2021/1/12-21:47.
 * 统一返回Rest风格的数据结构
 */
public class RestResult<T>  implements Serializable {
 
    /**
     * 成功的code码
     */
    private String code = "2000";
    /**
     * 成功时返回的数据，失败时返回具体的异常信息
     */
    private T data;
    /**
     * 请求失败返回的提示信息，给前端进行页面展示的信息
     */
    private String message ; 
    public RestResult() {
    }
 
    @Override
    public String toString() {
 
        return "RestResult{" +
                "code='" + code + '\'' +
                ", data=" + data +
                ", message=" + message +
                '}';
    }
 
    public RestResult(String code, T data, String message) {
        this.code = code;
        this.data = data;
        this.message = message;
    }
 
    public String getCode() {
        return code;
    }
 
    public void setCode(String code) {
        this.code = code;
    }
 
    public T getData() {
        return data;
    }
 
    public void setData(T data) {
        this.data = data;
    }
 
    public String getMessage() {
        return message;
    }
 
    public void setMessage(String message) {
        this.message = message;
    }
}