ExtJs7.X grid filter remote 后台java条件封装注解

背景：

由ExtJs7.X grid使用filter插件进行remote过滤的时候，传递了不少filter条件参数，本文基于参数进行解析，并封装为注解。

源码：

1、Ext filter 参数实体相关类：

@Data
public class FilterParam {

    protected String operator;

    protected String property;

    private Object value;
}

@Data
public class FilterArrayRaw extends FilterParam {
    private List value;

    public FilterArrayRaw() {
    }

    public FilterArrayRaw(JSONObject jo) {
        this.operator = jo.getStr("operator");
        this.property = jo.getStr("property");
        this.value = jo.getJSONArray("value").toList(String.class);
    }
}

@Data
public class FilterNumberRaw extends FilterParam {
    private Double value;

    public FilterNumberRaw() {
    }

    public FilterNumberRaw(JSONObject jo) {
        this.operator = jo.getStr("operator");
        this.property = jo.getStr("property");
        this.value = jo.get("value", Double.class);
    }
}

@Data
public class FilterStringRaw extends FilterParam {

    private String value;

    public FilterStringRaw() {
    }

    public FilterStringRaw(JSONObject jo) {
        this.operator = jo.getStr("operator");
        this.property = jo.getStr("property");
        this.value = jo.get("value", String.class);
    }
}

 基于ExtJs Filter的主要数据类型进行实体类定义。

2、注解定义，用于解析前端传递的grid filter参数

@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface GridFilterParam {

    /**
     * 参数名称
     *
     * @return 参数名称
     */
    String name() default "";

    /**
     * 默认无需必传
     *
     * @return boolean
     */
    boolean required() default false;
}

3、注解解析，继承自 HandlerMethodArgumentResolver 类

import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONArray;
import cn.hutool.json.JSONObject;
import org.codia.admin.annotation.GridFilterParam;
import xxx.xxx.filter.FilterArrayRaw;
import xxx.xxx.filter.FilterNumberRaw;
import xxx.xxx.filter.FilterParam;
import xxx.xxx.filter.FilterStringRaw;
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.util.ArrayList;
import java.util.List;

@Component
public class GridFilterResolver implements HandlerMethodArgumentResolver {

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return parameter.hasParameterAnnotation(GridFilterParam.class);
    }

    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer, NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
        //得到 GridFilterParam 注解信息并将其转换成用来记录注解信息的 JSONRequestParamNamedValueInfo 对象
        GridFilterParam jsonRequestParam = parameter.getParameterAnnotation(GridFilterParam.class);
        JSONRequestParamNamedValueInfo namedValueInfo = new JSONRequestParamNamedValueInfo(jsonRequestParam.name(), jsonRequestParam.required());
        if (namedValueInfo.name.isEmpty()) {
            namedValueInfo.name = parameter.getParameterName();
            if (namedValueInfo.name == null) {
                throw new IllegalArgumentException(
                        "Name for argument type [" + parameter.getNestedParameterType().getName() +
                                "] not available, and parameter name information not found in class file either.");
            }
        }

        HttpServletRequest servletRequest = webRequest.getNativeRequest(HttpServletRequest.class);

        //获得对应的 value 的 JSON 字符串
        String jsonText = servletRequest.getParameter(namedValueInfo.name);
        if (StrUtil.isNotEmpty(jsonText)) {
            //得到参数的 Class
//            Class clazz = parameter.getParameterType();
//
//            //使用 Jackson 将 JSON 字符串转换成我们想要的对象类
//            ObjectMapper mapper = new ObjectMapper();
//            Object value = mapper.readValue(jsonText, clazz);

            JSONArray result = new JSONArray(jsonText);

            List params = new ArrayList<>(result.size());

            result.forEach(raw -> {
                JSONObject jo = new JSONObject(raw);
                String operator = jo.getStr("operator");
                if (StrUtil.isNotEmpty(operator)) {
                    switch (operator) {
                        case "in":
                        case "notin": {
                            //array
                            params.add(new FilterArrayRaw(jo));
                            break;
                        }
                        case "like": {
                            //string
                            params.add(new FilterStringRaw(jo));
                            break;
                        }
                        case "<":
                        case "<=":
                        case "==":
                        case ">":
                        case ">=":
                        case "!=":
                        default: {
                            //number
                            params.add(new FilterNumberRaw(jo));
                        }
                    }
                }
            });

            return params;
        }
        return null;
    }

    private static class JSONRequestParamNamedValueInfo {

        private String name;

        private boolean required;

        public JSONRequestParamNamedValueInfo(String name, boolean required) {
            this.name = name;
            this.required = required;
        }
    }
}

利用Spring框架进行参数解析，完成filter参数条件封装。

效果：

参考： ExtJs 7.X grid filter remote 自定义查询字段别名_sword_happy的博客-CSDN博客