添加重载方法。

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

@@ -27,7 +27,15 @@ public class NumberUtil {
         throw new IllegalStateException("Utility class");
     }
 
-    public static int sum(int... numbers) {
+    public static int sum(short... numbers) {
+        int result = 0;
+        for (short number : numbers) {
+            result += number;
+        }
+        return result;
+    }
+
+    public static long sum(int... numbers) {
         int result = 0;
         for (int number : numbers) {
             result += number;
@@ -42,4 +50,20 @@ public class NumberUtil {
         }
         return result;
     }
+
+    public static double sum(float... numbers) {
+        double result = 0;
+        for (double number : numbers) {
+            result += number;
+        }
+        return result;
+    }
+
+    public static double sum(double... numbers) {
+        double result = 0;
+        for (double number : numbers) {
+            result += number;
+        }
+        return result;
+    }
 }