修复类型转化失败问题

km-common/src/main/java/com/xiaojukeji/know/streaming/km/common/utils/CommonUtils.java

@@ -241,4 +241,14 @@ public class CommonUtils {
         }
         return intList;
     }
+
+    public static boolean isNumeric(String str){
+        for (int i = 0; i < str.length(); i++){
+            if (!Character.isDigit(str.charAt(i))){
+                return false;
+            }
+        }
+
+        return true;
+    }
 }