From 09a91c35f80ed52cc0a8c7f187161d00bede8214 Mon Sep 17 00:00:00 2001
From: xiang2lin <251481237@qq.com>
Date: Fri, 16 May 2025 13:34:43 +0800
Subject: [PATCH] =?UTF-8?q?=E7=A8=8E=E7=8E=87=E8=AE=A1=E7=AE=97?=
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---
 .../plugin/cinvoice/util/TaxCalculator.java   | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 base-buildpackage/src/main/java/com/hzya/frame/plugin/cinvoice/util/TaxCalculator.java

diff --git a/base-buildpackage/src/main/java/com/hzya/frame/plugin/cinvoice/util/TaxCalculator.java b/base-buildpackage/src/main/java/com/hzya/frame/plugin/cinvoice/util/TaxCalculator.java
new file mode 100644
index 00000000..4a93f4f4
--- /dev/null
+++ b/base-buildpackage/src/main/java/com/hzya/frame/plugin/cinvoice/util/TaxCalculator.java
@@ -0,0 +1,40 @@
+package com.hzya.frame.plugin.cinvoice.util;
+
+import java.math.BigDecimal;
+
+/**
+ * @Description 税额计算器
+ * @Author xiangerlin
+ * @Date 2025/5/9 11:26
+ **/
+public class TaxCalculator {
+    /**
+     * 计算税额的方法
+     *
+     * @param amountWithTax 含税金额（BigDecimal）
+     * @param taxRate       税率（BigDecimal，例如 new BigDecimal("0.13") 表示 13%）
+     * @return 税额（BigDecimal）
+     */
+    public static BigDecimal calculateTax(BigDecimal amountWithTax, BigDecimal taxRate) {
+        if (amountWithTax == null || taxRate == null || taxRate.compareTo(BigDecimal.ZERO) < 0) {
+            throw new IllegalArgumentException("参数错误");
+        }
+        // 不含税金额 = 含税金额 / (1 + 税率)
+        BigDecimal one = BigDecimal.ONE;
+        BigDecimal taxInclusiveRate = one.add(taxRate);
+        BigDecimal amountWithoutTax = amountWithTax.divide(taxInclusiveRate, 6, BigDecimal.ROUND_HALF_UP);
+
+        // 税额 = 含税金额 - 不含税金额
+        BigDecimal tax = amountWithTax.subtract(amountWithoutTax).setScale(2, BigDecimal.ROUND_HALF_UP);
+        return tax;
+    }
+
+    public static void main(String[] args) {
+        // 示例：含税金额为 113，税率为 13%
+        BigDecimal amountWithTax = new BigDecimal("568");
+        BigDecimal taxRate = new BigDecimal("0.09");
+
+        BigDecimal tax = calculateTax(amountWithTax, taxRate);
+        System.out.println("税额为: " + tax); // 输出结果应为 13.00
+    }
+}