--- a/test/hotspot/jtreg/runtime/appcds/UseAppCDS.java	Wed Dec 06 11:11:16 2017 +0100
+++ b/test/hotspot/jtreg/runtime/appcds/UseAppCDS.java	Wed Dec 13 15:37:48 2017 -0800
@@ -108,12 +108,14 @@
 
     public static List<String> toClassNames(String filename) throws IOException {
         ArrayList<String> classes = new ArrayList<>();
-        BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(filename)));
-        for (; ; ) {
-            String line = br.readLine();
-            if (line == null)
-                break;
-            classes.add(line.replaceAll("/", "."));
+        try (BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(filename)))) {
+            for (; ; ) {
+                String line = br.readLine();
+                if (line == null) {
+                    break;
+                }
+                classes.add(line.replaceAll("/", "."));
+            }
         }
         return classes;
     }