add test

mall-service/src/test/java/com/txz/mall/util/RandomUtilTest.java

@@ -0,0 +1,21 @@
+package com.txz.mall.util;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class RandomUtilTest {
+    
+    @Test
+    public void testUniqueRandom_withValidList_shouldReturnCorrectCount() {
+        List<Integer> originalList = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+        // List<Integer> originalList = Arrays.asList(1, 2);
+        int count = 1;
+        for (int i = 0; i < 20; i++) {
+            List<Integer> result = RandomUtil.uniqueRandom(originalList, count);
+            System.out.println(result);
+        }
+    }
+    
+}