Args 工具类的使用（参数判断）

配合全局异常处理，遇到不能容忍的错误就往外抛

notNull：字段判空

public JSONObject useCoupon(String coupon_code, JSONObject in) {
    // 1、获取参数
    String openid = in.getByPath("openid", String.class);
    String appid = in.getByPath("appid", String.class);

    // 2、非空判断
    Args.notNull(coupon_code, "URL 'coupon_code'");
    Args.notNull(openid, "requestBody 'openid'");
    Args.notNull(appid, "requestBody 'appid'");

    // 3、根据 coupon_code 找到 stockId
    CouponEntity couponEntity = couponDao.selectOne(new LambdaQueryWrapper<CouponEntity>()
            .eq(CouponEntity::getCode, coupon_code));
    Args.notNull(couponEntity, String.format("'coupon_code' %s 未找到对应的 stockId", coupon_code));

notEmpty：集合判空

List<JSONObject> coupon_list = coupon.toList(JSONObject.class);
Args.notEmpty(coupon_list, "'coupon.[]'");

check：校验

public int updatePrice(String orderId) {
      // 1、校验参数
      Args.notNull(orderId, "'order_id'");

      // 2、查询数据
      OrderEntity orderEntity = baseMapper.selectById(orderId);
      Args.check(orderEntity != null, "'order_id' 在数据库中不存在~");

positive：不能为负

/* 1、检查 非数组字段 */
Integer order_amount = in.getByPath("order_amount", Integer.class);// 订单总金额，单位为分
Args.positive(order_amount, "'order_amount'");

check：枚举校验

// 2.3 检查字段
String coupon_status = c.getByPath("coupon_status", String.class);// SENDED已发送，但未使用, USED已使用,EXPIRED已到期,EXCHANGED券到时间未支付，系统再退回券
Integer coupon_type = c.getByPath("coupon_type", Integer.class);// 1: 支付券 2 商家券
Integer to_type = c.getByPath("to_type", Integer.class);//  1 ：计入 2 :不计入

// 检查 参数合法性。
EnumUtils.check(Constant.CouponStatus.class, coupon_status, "coupon.[].coupon_status");
EnumUtils.checkFields(Constant.ToType.class, "num", to_type, "coupon.[].to_type");
EnumUtils.checkFields(Constant.CouponType.class, "num", coupon_type, "coupon.[].coupon_type");

Constant.java

package com.decathlon.easypromo.util;

import lombok.Getter;

/**
 * 常量
 *
 * @author 陶攀峰
 */
public class Constant {

    /**
     * TO 类型。
     * 1 Record to TO，2 Do not record to TO【平安=1，默认=2】
     *
     * @author 陶攀峰
     * @date 2021/3/24 上午9:51
     */
    @Getter
    public enum ToType {
        RECORD_TO(1),
        NOT_RECORD_TO(2);

        private int num;

        ToType(int num) {
            this.num = num;
        }
    }

    /**
     * 优惠卷四种状态
     *
     * @author 陶攀峰
     * @date 2021/3/24 上午9:37
     */
    public enum CouponStatus {
        SENDED,//已发送，但未使用
        USED,//已使用
        EXPIRED,//已到期
        EXCHANGED,//券到时间未支付，系统再退回券
    }

    /**
     * 优惠卷类型
     *
     * @author 陶攀峰
     * @date 2021/4/9 下午3:10
     */
    @Getter
    public enum CouponType {
        PAYMENT(1),// 支付券
        MERCHANT(2);// 商家券

        private int num;

        CouponType(int num) {
            this.num = num;
        }
    }
}

EnumUtils.java

package com.decathlon.easypromo.util;

import cn.hutool.core.util.EnumUtil;
import org.apache.http.util.Args;

import java.util.List;

/**
 * 枚举工具类
 *
 * @author 陶攀峰
 * @version 1.0
 * @date 2021/4/9 下午2:46
 */
public class EnumUtils {

    /**
     * 传入一个值 var，检查是否存在枚举列表 clazz 中
     *
     * @param clazz     枚举类的 class 对象
     * @param var       传入参数
     * @param paramName 参数名
     * @author 陶攀峰
     * @date 2021/4/9 下午2:52
     */
    public static void check(Class clazz, Object var, String paramName) {
        Args.check(EnumUtil.contains(clazz, var.toString().toUpperCase()), "'%s' should in %s", paramName, EnumUtil.getNames(clazz));
    }

    /**
     * 传入一个值 var，检查是否存在枚举类的属性 fieldName 列表中
     *
     * @param clazz     枚举类的 class 对象
     * @param fieldName 枚举类成员属性名称
     * @param var       传入参数
     * @param paramName 参数名
     * @author 陶攀峰
     * @date 2021/4/9 下午4:59
     */
    public static void checkFields(Class clazz, String fieldName, Object var, String paramName) {
        List<Object> fieldValues = EnumUtil.getFieldValues(clazz, fieldName);
        Args.check(fieldValues.contains(var), "'%s' should in %s", paramName, fieldValues);
    }

}

Args：源码

<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpcore -->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpcore</artifactId>
    <version>4.4.14</version>
</dependency>

package org.apache.http.util;

import java.util.Collection;

public class Args {

    public static void check(final boolean expression, final String message) {
        if (!expression) {
            throw new IllegalArgumentException(message);
        }
    }

    public static void check(final boolean expression, final String message, final Object... args) {
        if (!expression) {
            throw new IllegalArgumentException(String.format(message, args));
        }
    }

    public static void check(final boolean expression, final String message, final Object arg) {
        if (!expression) {
            throw new IllegalArgumentException(String.format(message, arg));
        }
    }

    public static <T> T notNull(final T argument, final String name) {
        if (argument == null) {
            throw new IllegalArgumentException(name + " may not be null");
        }
        return argument;
    }

    public static <T extends CharSequence> T notEmpty(final T argument, final String name) {
        if (argument == null) {
            throw new IllegalArgumentException(name + " may not be null");
        }
        if (TextUtils.isEmpty(argument)) {
            throw new IllegalArgumentException(name + " may not be empty");
        }
        return argument;
    }

    public static <T extends CharSequence> T notBlank(final T argument, final String name) {
        if (argument == null) {
            throw new IllegalArgumentException(name + " may not be null");
        }
        if (TextUtils.isBlank(argument)) {
            throw new IllegalArgumentException(name + " may not be blank");
        }
        return argument;
    }

    public static <T extends CharSequence> T containsNoBlanks(final T argument, final String name) {
        if (argument == null) {
            throw new IllegalArgumentException(name + " may not be null");
        }
        if (argument.length() == 0) {
            throw new IllegalArgumentException(name + " may not be empty");
        }
        if (TextUtils.containsBlanks(argument)) {
            throw new IllegalArgumentException(name + " may not contain blanks");
        }
        return argument;
    }

    public static <E, T extends Collection<E>> T notEmpty(final T argument, final String name) {
        if (argument == null) {
            throw new IllegalArgumentException(name + " may not be null");
        }
        if (argument.isEmpty()) {
            throw new IllegalArgumentException(name + " may not be empty");
        }
        return argument;
    }

    public static int positive(final int n, final String name) {
        if (n <= 0) {
            throw new IllegalArgumentException(name + " may not be negative or zero");
        }
        return n;
    }

    public static long positive(final long n, final String name) {
        if (n <= 0) {
            throw new IllegalArgumentException(name + " may not be negative or zero");
        }
        return n;
    }

    public static int notNegative(final int n, final String name) {
        if (n < 0) {
            throw new IllegalArgumentException(name + " may not be negative");
        }
        return n;
    }

    public static long notNegative(final long n, final String name) {
        if (n < 0) {
            throw new IllegalArgumentException(name + " may not be negative");
        }
        return n;
    }

}