添加 BigDecimal 的 equal 方法。

src/main/java/xyz/zhouxy/plusone/commons/util/BigDecimals.java

@@ -0,0 +1,14 @@
+package xyz.zhouxy.plusone.commons.util;
+
+import java.math.BigDecimal;
+
+public class BigDecimals {
+
+    public static boolean equals(BigDecimal a, BigDecimal b) {
+        return (a == b) || (a != null && a.compareTo(b) == 0);
+    }
+
+    private BigDecimals() {
+        throw new IllegalStateException("Utility class");
+    }
+}