1 /*
   2  * Copyright (c) 2015, 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 8020968
  27  * @summary Basic test for Stream<StackFrame> state
  28  * @run main StackStreamState
  29  */
  30 
  31 import java.lang.StackWalker.StackFrame;
  32 import java.util.stream.Stream;
  33 
  34 public class StackStreamState {
  35     public static void main(String... args) {
  36         StackStreamState test = new StackStreamState();
  37         test.testStatic();
  38         test.testInstance();
  39         test.testLocal();
  40     }
  41 
  42     private static Stream<StackFrame> staticStream;
  43     private Stream<StackFrame> instanceStream;
  44     private final StackWalker walker = StackWalker.getInstance();
  45     void testStatic() {
  46         walker.walk(s -> {
  47             staticStream = s;
  48             return null;
  49         });
  50         checkStreamState(staticStream);
  51     }
  52     void testInstance() {
  53         walker.walk(s -> {
  54             instanceStream = s;
  55             return null;
  56         });
  57         checkStreamState(instanceStream);
  58     }
  59     void testLocal() {
  60         Stream<StackFrame> stream = walker.walk(s -> {
  61             return s;
  62         });
  63         checkStreamState(stream);
  64     }
  65     void checkStreamState(Stream<StackFrame> stream) {
  66         try {
  67             stream.count();
  68             throw new RuntimeException("IllegalStateException not thrown");
  69         } catch (IllegalStateException e) {
  70             System.out.println("Got expected IllegalStateException: " + e.getMessage());
  71             e.printStackTrace(System.out);
  72         }
  73     }
  74 }