1 /*
   2  * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 7020047
  27  * @summary Test null handling of try-with-resources statement
  28  */
  29 
  30 public class TwrNullTests {
  31     /*
  32      * Each try-with-resources statement generates two calls to the
  33      * close method for each resource: one for when there is a primary
  34      * exception present and the second for when a primary exception
  35      * is absent.  The null handling of both cases needs to be
  36      * checked.
  37      */
  38     public static void main(String... args) {
  39         testNormalCompletion();
  40         testNoSuppression();
  41     }
  42 
  43     /*
  44      * Verify empty try-with-resources on a null resource completes
  45      * normally; no NPE from the generated close call.
  46      */
  47     private static void testNormalCompletion() {
  48         try(AutoCloseable resource = null) {
  49             return; // Nothing so see here, move along.
  50         } catch (Exception e) {
  51             throw new AssertionError("Should not be reached", e);
  52         }
  53     }
  54 
  55     /*
  56      * Verify that a NPE on a null resource is <em>not</em> added as a
  57      * suppressed exception to an exception from try block.
  58      */
  59     private static void testNoSuppression() {
  60         try(AutoCloseable resource = null) {
  61             throw new java.io.IOException();
  62         } catch(java.io.IOException ioe) {
  63             Throwable[] suppressed = ioe.getSuppressed();
  64             if (suppressed.length != 0) {
  65                 throw new AssertionError("Non-empty suppressed exceptions",
  66                                          ioe);
  67             }
  68         } catch (Exception e) {
  69             throw new AssertionError("Should not be reached", e);
  70         }
  71     }
  72 }