博客

问题：post请求，只有一两个参数时，不想再定义一个对象进行接收，直接使用String是接收不到的。

1、定义一个注解：@RequestJson

/**
 * @author zp
 * @date 2022/5/26 9:07
 * post请求时前台传来的String类型参数
 */
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface RequestJson {

    String value();

}

2、注解的具体实现:

import com.alibaba.fastjson.JSONObject;
import com.ruoyi.framework.annotation.RequestJson;
import org.springframework.core.MethodParameter;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;

import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;

/**
 * @author zp
 * @date 2022/5/26 9:14
 */
@Component
public class RequestJsonMethodArgumentResolver implements HandlerMethodArgumentResolver {
    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.hasParameterAnnotation(RequestJson.class);
    }

    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
        RequestJson requestJson = parameter.getParameterAnnotation(RequestJson.class);
        HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
        BufferedReader reader = request.getReader();
        StringBuilder sb = new StringBuilder();
        char[] buf = new char[1024];
        int rd;
        while ((rd = reader.read(buf)) != -1) {
            sb.append(buf, 0, rd);
        }
        JSONObject jsonObject = JSONObject.parseObject(sb.toString());
        String value = requestJson.value();
        if (jsonObject == null) {
            return null;
        }
        return jsonObject.get(value);
    }
}

3、注册到配置文件中去

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

	@Autowired
    private RequestJsonMethodArgumentResolver requestJsonMethodArgumentResolver;
    
	@Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
        argumentResolvers.add(requestJsonMethodArgumentResolver);
    }
}

END；

Controller层方法：

	@ApiOperation("测试RequestJson注解")
    @PostMapping("/test")
    public R test(@RequestJson("name")@NotBlank(message = "不能为空") String name, @RequestJson("sex")Integer sex){
        return R.ok(name+"----"+sex);
    }

参数：