自定义@RequestBody注解如何获取JSON数据

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.PARAMETER)
public @interface JsonArg {
    @AliasFor("name")
    String value() default "";

    @AliasFor("value")
    String name() default "";

    boolean required() default true;

    String defaultValue() default ValueConstants.DEFAULT_NONE;
}

public class JsonArgMethodArgumentResolver extends AbstractNamedValueMethodArgumentResolver {
    
    @Override
    protected NamedValueInfo createNamedValueInfo(MethodParameter parameter) {
        JsonArg ann = parameter.getParameterAnnotation(JsonArg.class);
        return (ann != null ? new JsonArgNamedValueInfo(ann) : new JsonArgNamedValueInfo());
    }

    
    @Override
    protected Object resolveName(String name, MethodParameter parameter, NativeWEBRequest request) throws Exception {
        ContentCachingRequestWrapper contentCachingRequestWrapper = request.getNativeRequest(ContentCachingRequestWrapper.class);
        String body;
        assert contentCachingRequestWrapper != null;
        byte[] contentAsByteArray = contentCachingRequestWrapper.getContentAsByteArray();
        if (contentAsByteArray.length == 0) {
            try (BufferedReader reader = contentCachingRequestWrapper.getReader()) {
                body = reader.lines().collect(Collectors.joining(""));
            }
        } else {
            body = new String(contentAsByteArray);
        }
        return JSONObject.parseObject(body).get(name);
    }

    
    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return true;
    }

    private static class JsonArgNamedValueInfo extends NamedValueInfo {
        public JsonArgNamedValueInfo() {
            super("", false, ValueConstants.DEFAULT_NONE);
        }

        public JsonArgNamedValueInfo(JsonArg annotation) {
            super(annotation.name(), annotation.required(), annotation.defaultValue());
        }
    }
}

@Component
public class CachingRequestBodyFilter extends GenericFilterBean {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        if (servletRequest instanceof httpservletRequest) {
            filterChain.doFilter(new ContentCachingRequestWrapper((HttpServletRequest) servletRequest), servletResponse);
        } else {
            filterChain.doFilter(servletRequest, servletResponse);
        }
    }
}

@Configuration
public class springMVCConfig implements WebMvcConfigurer {
    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers) {
        resolvers.add(new JsonArgMethodArgumentResolver());
    }
}

public CommonResult<Object> signUp(
            @JsonArg(name = "uname") String username,
            @JsonArg(required = false, name = "pwd", defaultValue = "123") String passWord
    ) {
        log.info("[Username]: {}, [Password]: {}", username, password);
        return null;
}