java 按照自定义顺序枚举实体类的属性值

工具类

    /**
     * 按照字段顺序进行拼接
     *
     * @param obj 对象，需要在字段上添加FieldOrder注解
     * @param fix 拼接符号
     * @param <T>
     * @return
     * @author JeWang
     */
    public static <T> String toSpit(T obj, String fix) throws IllegalAccessException {
        String ret = "";
        Field[] declaredFields = obj.getClass().getDeclaredFields();
        Field[] fields = new Field[declaredFields.length];
        for (Field declaredField : declaredFields) {
            FieldOrder annotation = declaredField.getAnnotation(FieldOrder.class);
            int order = annotation.order();
            fields[order - 1] = declaredField;
        }
        for (Field field : fields) {
            field.setAccessible(true);
            Object o = field.get(obj);
            if (o == null) {
                ret = ret + "" + fix;
            } else {
                ret = ret + o + fix;
            }
        }
        return ret;

注解

package cn.daenx.japi.bank.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface FieldOrder {

    /**
     * 标注该属性的顺序
     * 从1开始，不可跳跃
     *
     * @return 该属性的顺序
     */
    int order();
}

示例实体类

package cn.daenx.japi.bank.vo.req;

import cn.daenx.japi.bank.annotation.FieldOrder;
import lombok.Data;

@Data
public class R0804ReqVo {

    /**
     * 交易代码
     */
    @FieldOrder(order = 1)
    private String tradeCode;

    /**
     * POS厂商代码
     */
    @FieldOrder(order = 2)
    private String posFirmCode;

    /**
     * POS唯一编号
     */
    @FieldOrder(order = 3)
    private String posOnlyCode;

    /**
     * 银行卡账户名称
     */
    @FieldOrder(order = 4)
    private String bankAccountName;

    /**
     * 银行卡账户账号
     */
    @FieldOrder(order = 5)
    private String bankAccountNumber;

    /**
     * 银行卡发卡行
     */
    @FieldOrder(order = 6)
    private String bankIssuer;

    /**
     * 发起方
     */
    @FieldOrder(order = 7)
    private String fromType;
}

使用方法

      //生成请求内容
        String reqStr;
        try {
            reqStr = CommonUtils.toSpit(vo, "|");
        } catch (IllegalAccessException e) {
            return new R0801ResVo("请求数据转换失败");
        }