Java实现单位换算功能

Java实现单位换算功能

本文实例为大家分享了java实现单位换算功能的具体代码，供大家参考，具体内容如下

使用枚举进行简单计算

只加入了一些简单常用的单位,如有需要自行添加,以标准单位为基准

package com.dessert.common.enu;

import org.apache.commons.lang3.StringUtils;

import java.math.BigDecimal;

public class UnitConversion {

/**

* 默认保留两位小数,四舍五入

*

* @param value 原始数值

* @param original 原始单位

* @param need 转换的单位

* @return

*/

public static BigDecimal conversion(BigDecimal value, UnitsEnum original, UnitsEnum need) {

return conversion(value, original, need, 2);

}

/**

* @param value 原始数值

* @param original 原始单位

* @param need 转换的单位

* @param scale 小数点位数

* @return

*/

public static BigDecimal conversion(BigDecimal value, UnitsEnum original, UnitsEnum need, int scale) {

if (original == UnitsEnum.UN_KNOWN || need == UnitsEnum.UN_KNOWN) {

throw new IllegalArgumentException("存在不支持的单位参数");

}

if (original.category != need.category) {

throw new IllegalArgumentException("转换单位不统一!" + original.category.name + "不能转换为" + need.category.name);

}

return value == null ? new BigDecimal(0) : value.multiply(need.rate).divide(original.rate, scale, BigDecimal.ROUND_HALF_UP);

}

/**

* 默认保留两位小数,四舍五入

*

* @param value 原始数值

* @param original 原始单位

* @param need 转换的单位

* @return

*/

public static BigDecimal conversion(BigDecimal value, String original, String need) {

return conversion(value, getUnitEnum(original), getUnitEnum(need));

}

public static UnitsEnum getUnitEnum(String unit) {

if (StringUtils.isNotEmpty(unit)) {

for (UnitsEnum unitEnum : UnitsEnum.values()) {

for (String possibleName : unitEnum.possibleNames) {

if (possibleName.equals(unit.toLowerCase())) {

return unitEnum;

}

}

}

}

return UnitsEnum.UN_KNOWN;

}

public enum UnitsEnum {

LG_KM(CategoryEnum.LENGTH, "km", new String[]{"km", "千米"}, new BigDecimal("0.001"), "千米"),

LG_M(CategoryEnum.LENGTH, "m", new String[]{"m", "米"}, new BigDecimal("1"), "米"),

LG_Dm(CategoryEnum.LENGTH, "dm", new String[]{"dm", "分米"}, new BigDecimal("10"), "分米"),

LG_CM(CategoryEnum.LENGTH, "cm", new String[]{"cm", "厘米"}, new BigDecimal("100"), "厘米"),

LG_MM(CategoryEnum.LENGTH, "mm", new String[]{"mm", "毫米"}, new BigDecimal("1000"), "毫米"),

LG_UM(CategoryEnum.LENGTH, "um", new String[]{"um", "微米"}, new BigDecimal("1000000"), "微米"),

LG_NM(CategoryEnum.LENGTH, "nm", new String[]{"nm", "纳米"}, new BigDecimal("1000000000"), "纳米"),

LG_INCH(CategoryEnum.LENGTH, "inch", new String[]{"in", "inch", "英寸"}, new BigDecimal("39.3700787"), "英寸"),

EG_T(CategoryEnum.WEIGHT, "t", new String[]{"t", "吨"}, new BigDecimal("0.001"), "吨"),

EG_KG(CategoryEnum.WEIGHT, "kg", new String[]{"kg", "千克"}, new BigDecimal("1"), "千克"),

EG_G(CategoryEnum.WEIGHT, "g", new String[]{"g", "克"}, new BigDecimal("1000"), "克"),

EG_MG(CategoryEnum.WEIGHT, "mg", new String[]{"mg", "毫克"}, new BigDecimal("1000000"), "毫克"),

EG_UG(CategoryEnum.WEIGHT, "g", new String[]{"g", "ug", "微克"}, new BigDecimal("1000000000"), "微克"),

EG_LB(CategoryEnum.WEIGHT, "lb", new String[]{"lb", "lbs", "磅"}, new BigDecimal("2.2046226"), "磅"),

EG_OZ(CategoryEnum.WEIGHT, "oz", new String[]{"oz", "盎司"}, new BigDecimal("35.2739619"), "盎司"),

EG_CT(CategoryEnum.WEIGHT, "ct", new String[]{"ct", "克拉"}, new BigDecimal("5000"), "克拉"),

UN_KNOWN(null, "未知", null, new BigDecimal("0"), "未知");

private CategoryEnum category;

private String units;

private String[] possibleNames;

private BigDecimal rate;

private String description;

UnitsEnum(CategoryEnum category, String units, String[] possibleNames, BigDecimal rate, String description) {

this.category = category;

this.units = units;

this.possibleNames = possibleNames;

this.rate = rate;

this.description = description;

}

public CategoryEnum getCategory() {

return category;

}

public String getUnits() {

return units;

}

public String[] getPossibleNaeIbaCOYmes() {

return possibleNames;

}

public BigDecimal getRate() {

return rate;

}

public String getDescription() {

return description;

}

private enum CategoryEnum {

LENGTH("length", UnitsEnum.LG_M, "长度"),

WEIGHT("weight", UnitsEnum.EG_KG, "重量");

private String name;

private UnitsEnum base;

private String description;

CategoryEnum(String name, UnitsEnum base, String description) {

this.name = name;

this.base = base;

this.description = description;

}

public String getName() {

return name;

}

public UnitsEnum getBase() {

return base;

}

public String getDescription() {

return description;

}

}

}

}

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