test/hotspot/jtreg/runtime/appcds/test-classes/Util.java

@@ -37,11 +37,11 @@
      */
     public static Class defineModifiedClass(ClassLoader loader, File clsFile, String fromString, String toString)
         throws FileNotFoundException, IOException, NoSuchMethodException, IllegalAccessException,
                InvocationTargetException
     {
-        DataInputStream dis = new DataInputStream(new FileInputStream(clsFile));
+      try (DataInputStream dis = new DataInputStream(new FileInputStream(clsFile))) {
         byte[] buff = new byte[(int)clsFile.length()];
         dis.readFully(buff);
         replace(buff, fromString, toString);
 
         System.out.println("Loading from: " + clsFile + " (" + buff.length + " bytes)");

@@ -56,10 +56,11 @@
         Class cls = (Class)defineClass.invoke(loader, buff, new Integer(0), new Integer(buff.length));
         System.out.println("Loaded : " + cls);
 
         return cls;
     }
+    }
 
     /**
      * @return the number of occurrences of the <code>from</code> string that
      * have been replaced.
      */

@@ -144,13 +145,12 @@
 
     public static byte[] getClassFileFromJar(File jarFile, String className) throws FileNotFoundException, IOException {
         JarFile jf = new JarFile(jarFile);
         JarEntry ent = jf.getJarEntry(className.replace('.', '/') + ".class");
 
-        DataInputStream dis = new DataInputStream(jf.getInputStream(ent));
+        try (DataInputStream dis = new DataInputStream(jf.getInputStream(ent))) {
         byte[] buff = new byte[(int)ent.getSize()];
         dis.readFully(buff);
-        dis.close();
-
         return buff;
     }
+    }
 }