1 /*
   2  * Copyright (c) 2000, 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 import java.io.*;
  25 import java.util.*;
  26 
  27 /*
  28  * @test
  29  * @bug     4202914 4363318 6991528 6998871
  30  * @summary Basic test of serialization of stack trace information
  31  * @author  Josh Bloch
  32  */
  33 
  34 public class StackTraceSerialization {
  35     public static void main(String args[]) throws Exception {
  36         testWithSetStackTrace();
  37         testWithFillInStackTrace();
  38     }
  39 
  40     private static void testWithSetStackTrace() {
  41         StackTraceElement[] stackTrace = {new StackTraceElement("foo", "bar", "baz", -1)};
  42 
  43         Throwable t = new TestThrowable(true, false); // Immutable and empty stack
  44         assertEmptyStackTrace(t);
  45 
  46         // Verify fillInStackTrace is now a no-op.
  47         t.fillInStackTrace();
  48         assertEmptyStackTrace(t);
  49 
  50         // Verify setStackTrace is now a no-op.
  51         t.setStackTrace(stackTrace);
  52         assertEmptyStackTrace(t);
  53 
  54         // Verify null-handling
  55         try {
  56             t.setStackTrace(null);
  57             throw new RuntimeException("No NPE on a null stack trace.");
  58         } catch(NullPointerException npe) {
  59             assertEmptyStackTrace(t);
  60         }
  61 
  62         try {
  63             t.setStackTrace(new StackTraceElement[]{null});
  64             throw new RuntimeException("No NPE on a null stack trace element.");
  65         } catch(NullPointerException npe) {
  66             assertEmptyStackTrace(t);
  67         }
  68 
  69         if (!equal(t, reconstitute(t)))
  70             throw new RuntimeException("Unequal Throwables with set stacktrace");
  71 
  72         Throwable t2 = new Throwable();
  73         t2.setStackTrace(stackTrace);
  74         if (!equal(t2, reconstitute(t2)))
  75             throw new RuntimeException("Unequal Throwables with set stacktrace");
  76 
  77     }
  78 
  79     private static class TestThrowable extends Throwable {
  80         public TestThrowable(boolean enableSuppression,
  81                              boolean writableStackTrace) {
  82             super("the medium", null,
  83                   enableSuppression,
  84                   writableStackTrace);
  85         }
  86     }
  87 
  88     private static void assertEmptyStackTrace(Throwable t) {
  89         if (t.getStackTrace().length != 0)
  90             throw new AssertionError("Nonempty stacktrace.");
  91     }
  92 
  93     private static void testWithFillInStackTrace() {
  94         Throwable original = null;
  95         try {
  96             a();
  97         } catch(HighLevelException e) {
  98             original = e;
  99         }
 100 
 101         if (!equal(original, reconstitute(original)))
 102             throw new RuntimeException("Unequal Throwables with filled-in stacktrace");
 103     }
 104     
 105     /**
 106      * Serialize the argument and return the deserialized result.
 107      */
 108     private static Throwable reconstitute(Throwable t) {
 109         Throwable result = null;
 110         try(ByteArrayOutputStream bout = new ByteArrayOutputStream();
 111             ObjectOutputStream out = new ObjectOutputStream(bout)) {
 112             out.writeObject(t);
 113             out.flush();
 114             try(ByteArrayInputStream bin =
 115                 new ByteArrayInputStream(bout.toByteArray());
 116                 ObjectInputStream in = new ObjectInputStream(bin)) {
 117                 result = (Throwable) in.readObject();
 118             }
 119         } catch(IOException | ClassNotFoundException e) {
 120             throw new RuntimeException(e);
 121         }
 122         return result;
 123     }
 124 
 125     /**
 126      * Returns true if e1 and e2 have equal stack traces and their
 127      * causes are recursively equal (by the same definition) and their
 128      * suppressed exception information is equals.  Returns false or
 129      * throws NullPointerExeption otherwise.
 130      */
 131     private static boolean equal(Throwable t1, Throwable t2) {
 132         return t1==t2 ||
 133             (Arrays.equals(t1.getStackTrace(), t2.getStackTrace()) &&
 134              equal(t1.getCause(), t2.getCause()) &&
 135              Objects.equals(t1.getSuppressed(), t2.getSuppressed()));
 136     }
 137 
 138     static void a() throws HighLevelException {
 139         try {
 140             b();
 141         } catch(MidLevelException e) {
 142             throw new HighLevelException(e);
 143         }
 144     }
 145     static void b() throws MidLevelException {
 146         c();
 147     }
 148     static void c() throws MidLevelException {
 149         try {
 150             d();
 151         } catch(LowLevelException e) {
 152             throw new MidLevelException(e);
 153         }
 154     }
 155     static void d() throws LowLevelException {
 156        e();
 157     }
 158     static void e() throws LowLevelException {
 159         throw new LowLevelException();
 160     }
 161 
 162     private static final String OUR_CLASS  = StackTraceSerialization.class.getName();
 163     private static final String OUR_FILE_NAME = "StackTraceSerialization.java";
 164 
 165     private static void check(StackTraceElement e, String methodName, int n) {
 166         if (!e.getClassName().equals(OUR_CLASS))
 167             throw new RuntimeException("Class: " + e);
 168         if (!e.getMethodName().equals(methodName))
 169             throw new RuntimeException("Method name: " + e);
 170         if (!e.getFileName().equals(OUR_FILE_NAME))
 171             throw new RuntimeException("File name: " + e);
 172         if (e.getLineNumber() != n)
 173             throw new RuntimeException("Line number: " + e);
 174     }
 175 }
 176 
 177 class HighLevelException extends Exception {
 178     HighLevelException(Throwable cause) { super(cause); }
 179 }
 180 
 181 class MidLevelException extends Exception {
 182     MidLevelException(Throwable cause)  { super(cause); }
 183 }
 184 
 185 class LowLevelException extends Exception {
 186 }