1181 lines
50 KiB
Java
1181 lines
50 KiB
Java
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/*
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* Copyright (C) 2014 The Android Open Source Project
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* Copyright (c) 1994, 2020, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation. Oracle designates this
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* particular file as subject to the "Classpath" exception as provided
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* by Oracle in the LICENSE file that accompanied this code.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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package java.lang;
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import dalvik.annotation.optimization.FastNative;
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import dalvik.annotation.optimization.NeverInline;
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import java.io.*;
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import java.util.*;
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/**
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* The {@code Throwable} class is the superclass of all errors and
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* exceptions in the Java language. Only objects that are instances of this
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* class (or one of its subclasses) are thrown by the Java Virtual Machine or
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* can be thrown by the Java {@code throw} statement. Similarly, only
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* this class or one of its subclasses can be the argument type in a
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* {@code catch} clause.
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*
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* For the purposes of compile-time checking of exceptions, {@code
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* Throwable} and any subclass of {@code Throwable} that is not also a
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* subclass of either {@link RuntimeException} or {@link Error} are
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* regarded as checked exceptions.
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*
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* <p>Instances of two subclasses, {@link java.lang.Error} and
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* {@link java.lang.Exception}, are conventionally used to indicate
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* that exceptional situations have occurred. Typically, these instances
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* are freshly created in the context of the exceptional situation so
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* as to include relevant information (such as stack trace data).
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*
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* <p>A throwable contains a snapshot of the execution stack of its
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* thread at the time it was created. It can also contain a message
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* string that gives more information about the error. Over time, a
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* throwable can {@linkplain Throwable#addSuppressed suppress} other
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* throwables from being propagated. Finally, the throwable can also
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* contain a <i>cause</i>: another throwable that caused this
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* throwable to be constructed. The recording of this causal information
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* is referred to as the <i>chained exception</i> facility, as the
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* cause can, itself, have a cause, and so on, leading to a "chain" of
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* exceptions, each caused by another.
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*
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* <p>One reason that a throwable may have a cause is that the class that
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* throws it is built atop a lower layered abstraction, and an operation on
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* the upper layer fails due to a failure in the lower layer. It would be bad
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* design to let the throwable thrown by the lower layer propagate outward, as
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* it is generally unrelated to the abstraction provided by the upper layer.
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* Further, doing so would tie the API of the upper layer to the details of
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* its implementation, assuming the lower layer's exception was a checked
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* exception. Throwing a "wrapped exception" (i.e., an exception containing a
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* cause) allows the upper layer to communicate the details of the failure to
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* its caller without incurring either of these shortcomings. It preserves
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* the flexibility to change the implementation of the upper layer without
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* changing its API (in particular, the set of exceptions thrown by its
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* methods).
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*
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* <p>A second reason that a throwable may have a cause is that the method
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* that throws it must conform to a general-purpose interface that does not
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* permit the method to throw the cause directly. For example, suppose
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* a persistent collection conforms to the {@link java.util.Collection
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* Collection} interface, and that its persistence is implemented atop
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* {@code java.io}. Suppose the internals of the {@code add} method
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* can throw an {@link java.io.IOException IOException}. The implementation
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* can communicate the details of the {@code IOException} to its caller
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* while conforming to the {@code Collection} interface by wrapping the
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* {@code IOException} in an appropriate unchecked exception. (The
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* specification for the persistent collection should indicate that it is
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* capable of throwing such exceptions.)
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*
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* <p>A cause can be associated with a throwable in two ways: via a
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* constructor that takes the cause as an argument, or via the
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* {@link #initCause(Throwable)} method. New throwable classes that
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* wish to allow causes to be associated with them should provide constructors
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* that take a cause and delegate (perhaps indirectly) to one of the
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* {@code Throwable} constructors that takes a cause.
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*
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* Because the {@code initCause} method is public, it allows a cause to be
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* associated with any throwable, even a "legacy throwable" whose
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* implementation predates the addition of the exception chaining mechanism to
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* {@code Throwable}.
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*
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* <p>By convention, class {@code Throwable} and its subclasses have two
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* constructors, one that takes no arguments and one that takes a
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* {@code String} argument that can be used to produce a detail message.
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* Further, those subclasses that might likely have a cause associated with
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* them should have two more constructors, one that takes a
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* {@code Throwable} (the cause), and one that takes a
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* {@code String} (the detail message) and a {@code Throwable} (the
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* cause).
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*
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* @author Josh Bloch (Added exception chaining and programmatic access to
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* stack trace in 1.4.)
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* @jls 11.2 Compile-Time Checking of Exceptions
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* @since 1.0
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*/
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public class Throwable implements Serializable {
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/** use serialVersionUID from JDK 1.0.2 for interoperability */
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@java.io.Serial
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private static final long serialVersionUID = -3042686055658047285L;
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/**
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* The JVM saves some indication of the stack backtrace in this slot.
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*/
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private transient Object backtrace;
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/**
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* Specific details about the Throwable. For example, for
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* {@code FileNotFoundException}, this contains the name of
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* the file that could not be found.
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*
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* @serial
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*/
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private String detailMessage;
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/**
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* Holder class to defer initializing sentinel objects only used
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* for serialization.
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*/
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private static class SentinelHolder {
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/**
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* {@linkplain #setStackTrace(StackTraceElement[]) Setting the
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* stack trace} to a one-element array containing this sentinel
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* value indicates future attempts to set the stack trace will be
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* ignored. The sentinel is equal to the result of calling:<br>
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* {@code new StackTraceElement("", "", null, Integer.MIN_VALUE)}
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*/
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public static final StackTraceElement STACK_TRACE_ELEMENT_SENTINEL =
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new StackTraceElement("", "", null, Integer.MIN_VALUE);
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/**
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* Sentinel value used in the serial form to indicate an immutable
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* stack trace.
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*/
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public static final StackTraceElement[] STACK_TRACE_SENTINEL =
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new StackTraceElement[] {STACK_TRACE_ELEMENT_SENTINEL};
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}
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// Android-removed: Use libcore.util.EmptyArray for the empty stack trace.
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// Adding the constant UNASSIGNED_STACK breaks serialization of some subclasses
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// /**
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// * A shared value for an empty stack.
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// */
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// private static final StackTraceElement[] UNASSIGNED_STACK = new StackTraceElement[0];
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/*
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* To allow Throwable objects to be made immutable and safely
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* reused by the JVM, such as OutOfMemoryErrors, fields of
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* Throwable that are writable in response to user actions, cause,
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* stackTrace, and suppressedExceptions obey the following
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* protocol:
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*
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* 1) The fields are initialized to a non-null sentinel value
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* which indicates the value has logically not been set.
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*
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* 2) Writing a null to the field indicates further writes
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* are forbidden
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*
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* 3) The sentinel value may be replaced with another non-null
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* value.
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*
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* For example, implementations of the HotSpot JVM have
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* preallocated OutOfMemoryError objects to provide for better
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* diagnosability of that situation. These objects are created
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* without calling the constructor for that class and the fields
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* in question are initialized to null. To support this
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* capability, any new fields added to Throwable that require
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* being initialized to a non-null value require a coordinated JVM
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* change.
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*/
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/**
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* The throwable that caused this throwable to get thrown, or null if this
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* throwable was not caused by another throwable, or if the causative
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* throwable is unknown. If this field is equal to this throwable itself,
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* it indicates that the cause of this throwable has not yet been
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* initialized.
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*
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* @serial
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* @since 1.4
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*/
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private Throwable cause = this;
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/**
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* The stack trace, as returned by {@link #getStackTrace()}.
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*
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* The field is initialized to a zero-length array. A {@code
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* null} value of this field indicates subsequent calls to {@link
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* #setStackTrace(StackTraceElement[])} and {@link
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* #fillInStackTrace()} will be no-ops.
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*
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* @serial
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* @since 1.4
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*/
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// Android-changed: Use libcore.util.EmptyArray for the empty stack trace.
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// private StackTraceElement[] stackTrace = UNASSIGNED_STACK;
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private StackTraceElement[] stackTrace = libcore.util.EmptyArray.STACK_TRACE_ELEMENT;
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/**
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* The JVM code sets the depth of the backtrace for later retrieval
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*/
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// Android-removed: native getStackTrace is used instead.
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// private transient int depth;
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// Android-removed: Use empty collection in place of SUPPRESSED_SENTINEL.
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// Adding this constant breaks serialization of some subclasses
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/*
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// Setting this static field introduces an acceptable
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// initialization dependency on a few java.util classes.
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private static final List<Throwable> SUPPRESSED_SENTINEL = Collections.emptyList();
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*/
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/**
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* The list of suppressed exceptions, as returned by {@link
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* #getSuppressed()}. The list is initialized to a zero-element
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* unmodifiable sentinel list. When a serialized Throwable is
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* read in, if the {@code suppressedExceptions} field points to a
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* zero-element list, the field is reset to the sentinel value.
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*
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* @serial
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* @since 1.7
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*/
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// Android-changed: Use empty collection in place of SUPPRESSED_SENTINEL.
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// @SuppressWarnings("serial") // Not statically typed as Serializable
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// private List<Throwable> suppressedExceptions = SUPPRESSED_SENTINEL;
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private List<Throwable> suppressedExceptions = Collections.emptyList();
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/** Message for trying to suppress a null exception. */
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private static final String NULL_CAUSE_MESSAGE = "Cannot suppress a null exception.";
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/** Message for trying to suppress oneself. */
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private static final String SELF_SUPPRESSION_MESSAGE = "Self-suppression not permitted";
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/** Caption for labeling causative exception stack traces */
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private static final String CAUSE_CAPTION = "Caused by: ";
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/** Caption for labeling suppressed exception stack traces */
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private static final String SUPPRESSED_CAPTION = "Suppressed: ";
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/**
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* Constructs a new throwable with {@code null} as its detail message.
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* The cause is not initialized, and may subsequently be initialized by a
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* call to {@link #initCause}.
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*
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* <p>The {@link #fillInStackTrace()} method is called to initialize
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* the stack trace data in the newly created throwable.
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*/
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public Throwable() {
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fillInStackTrace();
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}
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/**
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* Constructs a new throwable with the specified detail message. The
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* cause is not initialized, and may subsequently be initialized by
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* a call to {@link #initCause}.
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*
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* <p>The {@link #fillInStackTrace()} method is called to initialize
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* the stack trace data in the newly created throwable.
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*
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* @param message the detail message. The detail message is saved for
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* later retrieval by the {@link #getMessage()} method.
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*/
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public Throwable(String message) {
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fillInStackTrace();
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detailMessage = message;
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}
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/**
|
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* Constructs a new throwable with the specified detail message and
|
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* cause. <p>Note that the detail message associated with
|
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* {@code cause} is <i>not</i> automatically incorporated in
|
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* this throwable's detail message.
|
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*
|
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|
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* <p>The {@link #fillInStackTrace()} method is called to initialize
|
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* the stack trace data in the newly created throwable.
|
||
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*
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* @param message the detail message (which is saved for later retrieval
|
||
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* by the {@link #getMessage()} method).
|
||
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* @param cause the cause (which is saved for later retrieval by the
|
||
|
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* {@link #getCause()} method). (A {@code null} value is
|
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* permitted, and indicates that the cause is nonexistent or
|
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* unknown.)
|
||
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* @since 1.4
|
||
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*/
|
||
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public Throwable(String message, Throwable cause) {
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fillInStackTrace();
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detailMessage = message;
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this.cause = cause;
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}
|
||
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|
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|
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/**
|
||
|
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* Constructs a new throwable with the specified cause and a detail
|
||
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* message of {@code (cause==null ? null : cause.toString())} (which
|
||
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* typically contains the class and detail message of {@code cause}).
|
||
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* This constructor is useful for throwables that are little more than
|
||
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* wrappers for other throwables (for example, {@link
|
||
|
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* java.security.PrivilegedActionException}).
|
||
|
|
*
|
||
|
|
* <p>The {@link #fillInStackTrace()} method is called to initialize
|
||
|
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* the stack trace data in the newly created throwable.
|
||
|
|
*
|
||
|
|
* @param cause the cause (which is saved for later retrieval by the
|
||
|
|
* {@link #getCause()} method). (A {@code null} value is
|
||
|
|
* permitted, and indicates that the cause is nonexistent or
|
||
|
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* unknown.)
|
||
|
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* @since 1.4
|
||
|
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*/
|
||
|
|
public Throwable(Throwable cause) {
|
||
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fillInStackTrace();
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||
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detailMessage = (cause==null ? null : cause.toString());
|
||
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this.cause = cause;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Constructs a new throwable with the specified detail message,
|
||
|
|
* cause, {@linkplain #addSuppressed suppression} enabled or
|
||
|
|
* disabled, and writable stack trace enabled or disabled. If
|
||
|
|
* suppression is disabled, {@link #getSuppressed} for this object
|
||
|
|
* will return a zero-length array and calls to {@link
|
||
|
|
* #addSuppressed} that would otherwise append an exception to the
|
||
|
|
* suppressed list will have no effect. If the writable stack
|
||
|
|
* trace is false, this constructor will not call {@link
|
||
|
|
* #fillInStackTrace()}, a {@code null} will be written to the
|
||
|
|
* {@code stackTrace} field, and subsequent calls to {@code
|
||
|
|
* fillInStackTrace} and {@link
|
||
|
|
* #setStackTrace(StackTraceElement[])} will not set the stack
|
||
|
|
* trace. If the writable stack trace is false, {@link
|
||
|
|
* #getStackTrace} will return a zero length array.
|
||
|
|
*
|
||
|
|
* <p>Note that the other constructors of {@code Throwable} treat
|
||
|
|
* suppression as being enabled and the stack trace as being
|
||
|
|
* writable. Subclasses of {@code Throwable} should document any
|
||
|
|
* conditions under which suppression is disabled and document
|
||
|
|
* conditions under which the stack trace is not writable.
|
||
|
|
* Disabling of suppression should only occur in exceptional
|
||
|
|
* circumstances where special requirements exist, such as a
|
||
|
|
* virtual machine reusing exception objects under low-memory
|
||
|
|
* situations. Circumstances where a given exception object is
|
||
|
|
* repeatedly caught and rethrown, such as to implement control
|
||
|
|
* flow between two sub-systems, is another situation where
|
||
|
|
* immutable throwable objects would be appropriate.
|
||
|
|
*
|
||
|
|
* @param message the detail message.
|
||
|
|
* @param cause the cause. (A {@code null} value is permitted,
|
||
|
|
* and indicates that the cause is nonexistent or unknown.)
|
||
|
|
* @param enableSuppression whether or not suppression is enabled or disabled
|
||
|
|
* @param writableStackTrace whether or not the stack trace should be
|
||
|
|
* writable
|
||
|
|
*
|
||
|
|
* @see OutOfMemoryError
|
||
|
|
* @see NullPointerException
|
||
|
|
* @see ArithmeticException
|
||
|
|
* @since 1.7
|
||
|
|
*/
|
||
|
|
protected Throwable(String message, Throwable cause,
|
||
|
|
boolean enableSuppression,
|
||
|
|
boolean writableStackTrace) {
|
||
|
|
if (writableStackTrace) {
|
||
|
|
fillInStackTrace();
|
||
|
|
} else {
|
||
|
|
stackTrace = null;
|
||
|
|
}
|
||
|
|
detailMessage = message;
|
||
|
|
this.cause = cause;
|
||
|
|
if (!enableSuppression)
|
||
|
|
suppressedExceptions = null;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns the detail message string of this throwable.
|
||
|
|
*
|
||
|
|
* @return the detail message string of this {@code Throwable} instance
|
||
|
|
* (which may be {@code null}).
|
||
|
|
*/
|
||
|
|
public String getMessage() {
|
||
|
|
return detailMessage;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Creates a localized description of this throwable.
|
||
|
|
* Subclasses may override this method in order to produce a
|
||
|
|
* locale-specific message. For subclasses that do not override this
|
||
|
|
* method, the default implementation returns the same result as
|
||
|
|
* {@code getMessage()}.
|
||
|
|
*
|
||
|
|
* @return The localized description of this throwable.
|
||
|
|
* @since 1.1
|
||
|
|
*/
|
||
|
|
public String getLocalizedMessage() {
|
||
|
|
return getMessage();
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns the cause of this throwable or {@code null} if the
|
||
|
|
* cause is nonexistent or unknown. (The cause is the throwable that
|
||
|
|
* caused this throwable to get thrown.)
|
||
|
|
*
|
||
|
|
* <p>This implementation returns the cause that was supplied via one of
|
||
|
|
* the constructors requiring a {@code Throwable}, or that was set after
|
||
|
|
* creation with the {@link #initCause(Throwable)} method. While it is
|
||
|
|
* typically unnecessary to override this method, a subclass can override
|
||
|
|
* it to return a cause set by some other means. This is appropriate for
|
||
|
|
* a "legacy chained throwable" that predates the addition of chained
|
||
|
|
* exceptions to {@code Throwable}. Note that it is <i>not</i>
|
||
|
|
* necessary to override any of the {@code PrintStackTrace} methods,
|
||
|
|
* all of which invoke the {@code getCause} method to determine the
|
||
|
|
* cause of a throwable.
|
||
|
|
*
|
||
|
|
* @return the cause of this throwable or {@code null} if the
|
||
|
|
* cause is nonexistent or unknown.
|
||
|
|
* @since 1.4
|
||
|
|
*/
|
||
|
|
public synchronized Throwable getCause() {
|
||
|
|
return (cause==this ? null : cause);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Initializes the <i>cause</i> of this throwable to the specified value.
|
||
|
|
* (The cause is the throwable that caused this throwable to get thrown.)
|
||
|
|
*
|
||
|
|
* <p>This method can be called at most once. It is generally called from
|
||
|
|
* within the constructor, or immediately after creating the
|
||
|
|
* throwable. If this throwable was created
|
||
|
|
* with {@link #Throwable(Throwable)} or
|
||
|
|
* {@link #Throwable(String,Throwable)}, this method cannot be called
|
||
|
|
* even once.
|
||
|
|
*
|
||
|
|
* <p>An example of using this method on a legacy throwable type
|
||
|
|
* without other support for setting the cause is:
|
||
|
|
*
|
||
|
|
* <pre>
|
||
|
|
* try {
|
||
|
|
* lowLevelOp();
|
||
|
|
* } catch (LowLevelException le) {
|
||
|
|
* throw (HighLevelException)
|
||
|
|
* new HighLevelException().initCause(le); // Legacy constructor
|
||
|
|
* }
|
||
|
|
* </pre>
|
||
|
|
*
|
||
|
|
* @param cause the cause (which is saved for later retrieval by the
|
||
|
|
* {@link #getCause()} method). (A {@code null} value is
|
||
|
|
* permitted, and indicates that the cause is nonexistent or
|
||
|
|
* unknown.)
|
||
|
|
* @return a reference to this {@code Throwable} instance.
|
||
|
|
* @throws IllegalArgumentException if {@code cause} is this
|
||
|
|
* throwable. (A throwable cannot be its own cause.)
|
||
|
|
* @throws IllegalStateException if this throwable was
|
||
|
|
* created with {@link #Throwable(Throwable)} or
|
||
|
|
* {@link #Throwable(String,Throwable)}, or this method has already
|
||
|
|
* been called on this throwable.
|
||
|
|
* @since 1.4
|
||
|
|
*/
|
||
|
|
public synchronized Throwable initCause(Throwable cause) {
|
||
|
|
if (this.cause != this)
|
||
|
|
throw new IllegalStateException("Can't overwrite cause with " +
|
||
|
|
Objects.toString(cause, "a null"), this);
|
||
|
|
if (cause == this)
|
||
|
|
throw new IllegalArgumentException("Self-causation not permitted", this);
|
||
|
|
this.cause = cause;
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* This is called by readObject of a few exceptions such as
|
||
|
|
* ClassNotFoundException and ExceptionInInitializerError to deserialize
|
||
|
|
* a stream output from an older runtime version where the cause may
|
||
|
|
* have set to null.
|
||
|
|
*/
|
||
|
|
final void setCause(Throwable t) {
|
||
|
|
this.cause = t;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns a short description of this throwable.
|
||
|
|
* The result is the concatenation of:
|
||
|
|
* <ul>
|
||
|
|
* <li> the {@linkplain Class#getName() name} of the class of this object
|
||
|
|
* <li> ": " (a colon and a space)
|
||
|
|
* <li> the result of invoking this object's {@link #getLocalizedMessage}
|
||
|
|
* method
|
||
|
|
* </ul>
|
||
|
|
* If {@code getLocalizedMessage} returns {@code null}, then just
|
||
|
|
* the class name is returned.
|
||
|
|
*
|
||
|
|
* @return a string representation of this throwable.
|
||
|
|
*/
|
||
|
|
public String toString() {
|
||
|
|
String s = getClass().getName();
|
||
|
|
String message = getLocalizedMessage();
|
||
|
|
return (message != null) ? (s + ": " + message) : s;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Prints this throwable and its backtrace to the
|
||
|
|
* standard error stream. This method prints a stack trace for this
|
||
|
|
* {@code Throwable} object on the error output stream that is
|
||
|
|
* the value of the field {@code System.err}. The first line of
|
||
|
|
* output contains the result of the {@link #toString()} method for
|
||
|
|
* this object. Remaining lines represent data previously recorded by
|
||
|
|
* the method {@link #fillInStackTrace()}. The format of this
|
||
|
|
* information depends on the implementation, but the following
|
||
|
|
* example may be regarded as typical:
|
||
|
|
* <blockquote><pre>
|
||
|
|
* java.lang.NullPointerException
|
||
|
|
* at MyClass.mash(MyClass.java:9)
|
||
|
|
* at MyClass.crunch(MyClass.java:6)
|
||
|
|
* at MyClass.main(MyClass.java:3)
|
||
|
|
* </pre></blockquote>
|
||
|
|
* This example was produced by running the program:
|
||
|
|
* <pre>
|
||
|
|
* class MyClass {
|
||
|
|
* public static void main(String[] args) {
|
||
|
|
* crunch(null);
|
||
|
|
* }
|
||
|
|
* static void crunch(int[] a) {
|
||
|
|
* mash(a);
|
||
|
|
* }
|
||
|
|
* static void mash(int[] b) {
|
||
|
|
* System.out.println(b[0]);
|
||
|
|
* }
|
||
|
|
* }
|
||
|
|
* </pre>
|
||
|
|
* The backtrace for a throwable with an initialized, non-null cause
|
||
|
|
* should generally include the backtrace for the cause. The format
|
||
|
|
* of this information depends on the implementation, but the following
|
||
|
|
* example may be regarded as typical:
|
||
|
|
* <pre>
|
||
|
|
* HighLevelException: MidLevelException: LowLevelException
|
||
|
|
* at Junk.a(Junk.java:13)
|
||
|
|
* at Junk.main(Junk.java:4)
|
||
|
|
* Caused by: MidLevelException: LowLevelException
|
||
|
|
* at Junk.c(Junk.java:23)
|
||
|
|
* at Junk.b(Junk.java:17)
|
||
|
|
* at Junk.a(Junk.java:11)
|
||
|
|
* ... 1 more
|
||
|
|
* Caused by: LowLevelException
|
||
|
|
* at Junk.e(Junk.java:30)
|
||
|
|
* at Junk.d(Junk.java:27)
|
||
|
|
* at Junk.c(Junk.java:21)
|
||
|
|
* ... 3 more
|
||
|
|
* </pre>
|
||
|
|
* Note the presence of lines containing the characters {@code "..."}.
|
||
|
|
* These lines indicate that the remainder of the stack trace for this
|
||
|
|
* exception matches the indicated number of frames from the bottom of the
|
||
|
|
* stack trace of the exception that was caused by this exception (the
|
||
|
|
* "enclosing" exception). This shorthand can greatly reduce the length
|
||
|
|
* of the output in the common case where a wrapped exception is thrown
|
||
|
|
* from same method as the "causative exception" is caught. The above
|
||
|
|
* example was produced by running the program:
|
||
|
|
* <pre>
|
||
|
|
* public class Junk {
|
||
|
|
* public static void main(String args[]) {
|
||
|
|
* try {
|
||
|
|
* a();
|
||
|
|
* } catch(HighLevelException e) {
|
||
|
|
* e.printStackTrace();
|
||
|
|
* }
|
||
|
|
* }
|
||
|
|
* static void a() throws HighLevelException {
|
||
|
|
* try {
|
||
|
|
* b();
|
||
|
|
* } catch(MidLevelException e) {
|
||
|
|
* throw new HighLevelException(e);
|
||
|
|
* }
|
||
|
|
* }
|
||
|
|
* static void b() throws MidLevelException {
|
||
|
|
* c();
|
||
|
|
* }
|
||
|
|
* static void c() throws MidLevelException {
|
||
|
|
* try {
|
||
|
|
* d();
|
||
|
|
* } catch(LowLevelException e) {
|
||
|
|
* throw new MidLevelException(e);
|
||
|
|
* }
|
||
|
|
* }
|
||
|
|
* static void d() throws LowLevelException {
|
||
|
|
* e();
|
||
|
|
* }
|
||
|
|
* static void e() throws LowLevelException {
|
||
|
|
* throw new LowLevelException();
|
||
|
|
* }
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* class HighLevelException extends Exception {
|
||
|
|
* HighLevelException(Throwable cause) { super(cause); }
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* class MidLevelException extends Exception {
|
||
|
|
* MidLevelException(Throwable cause) { super(cause); }
|
||
|
|
* }
|
||
|
|
*
|
||
|
|
* class LowLevelException extends Exception {
|
||
|
|
* }
|
||
|
|
* </pre>
|
||
|
|
* As of release 7, the platform supports the notion of
|
||
|
|
* <i>suppressed exceptions</i> (in conjunction with the {@code
|
||
|
|
* try}-with-resources statement). Any exceptions that were
|
||
|
|
* suppressed in order to deliver an exception are printed out
|
||
|
|
* beneath the stack trace. The format of this information
|
||
|
|
* depends on the implementation, but the following example may be
|
||
|
|
* regarded as typical:
|
||
|
|
*
|
||
|
|
* <pre>
|
||
|
|
* Exception in thread "main" java.lang.Exception: Something happened
|
||
|
|
* at Foo.bar(Foo.java:10)
|
||
|
|
* at Foo.main(Foo.java:5)
|
||
|
|
* Suppressed: Resource$CloseFailException: Resource ID = 0
|
||
|
|
* at Resource.close(Resource.java:26)
|
||
|
|
* at Foo.bar(Foo.java:9)
|
||
|
|
* ... 1 more
|
||
|
|
* </pre>
|
||
|
|
* Note that the "... n more" notation is used on suppressed exceptions
|
||
|
|
* just as it is used on causes. Unlike causes, suppressed exceptions are
|
||
|
|
* indented beyond their "containing exceptions."
|
||
|
|
*
|
||
|
|
* <p>An exception can have both a cause and one or more suppressed
|
||
|
|
* exceptions:
|
||
|
|
* <pre>
|
||
|
|
* Exception in thread "main" java.lang.Exception: Main block
|
||
|
|
* at Foo3.main(Foo3.java:7)
|
||
|
|
* Suppressed: Resource$CloseFailException: Resource ID = 2
|
||
|
|
* at Resource.close(Resource.java:26)
|
||
|
|
* at Foo3.main(Foo3.java:5)
|
||
|
|
* Suppressed: Resource$CloseFailException: Resource ID = 1
|
||
|
|
* at Resource.close(Resource.java:26)
|
||
|
|
* at Foo3.main(Foo3.java:5)
|
||
|
|
* Caused by: java.lang.Exception: I did it
|
||
|
|
* at Foo3.main(Foo3.java:8)
|
||
|
|
* </pre>
|
||
|
|
* Likewise, a suppressed exception can have a cause:
|
||
|
|
* <pre>
|
||
|
|
* Exception in thread "main" java.lang.Exception: Main block
|
||
|
|
* at Foo4.main(Foo4.java:6)
|
||
|
|
* Suppressed: Resource2$CloseFailException: Resource ID = 1
|
||
|
|
* at Resource2.close(Resource2.java:20)
|
||
|
|
* at Foo4.main(Foo4.java:5)
|
||
|
|
* Caused by: java.lang.Exception: Rats, you caught me
|
||
|
|
* at Resource2$CloseFailException.<init>(Resource2.java:45)
|
||
|
|
* ... 2 more
|
||
|
|
* </pre>
|
||
|
|
*/
|
||
|
|
public void printStackTrace() {
|
||
|
|
printStackTrace(System.err);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Prints this throwable and its backtrace to the specified print stream.
|
||
|
|
*
|
||
|
|
* @param s {@code PrintStream} to use for output
|
||
|
|
*/
|
||
|
|
public void printStackTrace(PrintStream s) {
|
||
|
|
printStackTrace(new WrappedPrintStream(s));
|
||
|
|
}
|
||
|
|
|
||
|
|
private void printStackTrace(PrintStreamOrWriter s) {
|
||
|
|
// Guard against malicious overrides of Throwable.equals by
|
||
|
|
// using a Set with identity equality semantics.
|
||
|
|
Set<Throwable> dejaVu = Collections.newSetFromMap(new IdentityHashMap<>());
|
||
|
|
dejaVu.add(this);
|
||
|
|
|
||
|
|
synchronized (s.lock()) {
|
||
|
|
// Print our stack trace
|
||
|
|
s.println(this);
|
||
|
|
StackTraceElement[] trace = getOurStackTrace();
|
||
|
|
for (StackTraceElement traceElement : trace)
|
||
|
|
s.println("\tat " + traceElement);
|
||
|
|
|
||
|
|
// Print suppressed exceptions, if any
|
||
|
|
for (Throwable se : getSuppressed())
|
||
|
|
se.printEnclosedStackTrace(s, trace, SUPPRESSED_CAPTION, "\t", dejaVu);
|
||
|
|
|
||
|
|
// Print cause, if any
|
||
|
|
Throwable ourCause = getCause();
|
||
|
|
if (ourCause != null)
|
||
|
|
ourCause.printEnclosedStackTrace(s, trace, CAUSE_CAPTION, "", dejaVu);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Print our stack trace as an enclosed exception for the specified
|
||
|
|
* stack trace.
|
||
|
|
*/
|
||
|
|
private void printEnclosedStackTrace(PrintStreamOrWriter s,
|
||
|
|
StackTraceElement[] enclosingTrace,
|
||
|
|
String caption,
|
||
|
|
String prefix,
|
||
|
|
Set<Throwable> dejaVu) {
|
||
|
|
// Android-removed: Use of assert keyword which breaks serialization of some subclasses.
|
||
|
|
// (Using assert adds a static field that determines whether assertions are enabled.)
|
||
|
|
// assert Thread.holdsLock(s.lock());
|
||
|
|
if (dejaVu.contains(this)) {
|
||
|
|
s.println(prefix + caption + "[CIRCULAR REFERENCE: " + this + "]");
|
||
|
|
} else {
|
||
|
|
dejaVu.add(this);
|
||
|
|
// Compute number of frames in common between this and enclosing trace
|
||
|
|
StackTraceElement[] trace = getOurStackTrace();
|
||
|
|
int m = trace.length - 1;
|
||
|
|
int n = enclosingTrace.length - 1;
|
||
|
|
while (m >= 0 && n >=0 && trace[m].equals(enclosingTrace[n])) {
|
||
|
|
m--; n--;
|
||
|
|
}
|
||
|
|
int framesInCommon = trace.length - 1 - m;
|
||
|
|
|
||
|
|
// Print our stack trace
|
||
|
|
s.println(prefix + caption + this);
|
||
|
|
for (int i = 0; i <= m; i++)
|
||
|
|
s.println(prefix + "\tat " + trace[i]);
|
||
|
|
if (framesInCommon != 0)
|
||
|
|
s.println(prefix + "\t... " + framesInCommon + " more");
|
||
|
|
|
||
|
|
// Print suppressed exceptions, if any
|
||
|
|
for (Throwable se : getSuppressed())
|
||
|
|
se.printEnclosedStackTrace(s, trace, SUPPRESSED_CAPTION,
|
||
|
|
prefix +"\t", dejaVu);
|
||
|
|
|
||
|
|
// Print cause, if any
|
||
|
|
Throwable ourCause = getCause();
|
||
|
|
if (ourCause != null)
|
||
|
|
ourCause.printEnclosedStackTrace(s, trace, CAUSE_CAPTION, prefix, dejaVu);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Prints this throwable and its backtrace to the specified
|
||
|
|
* print writer.
|
||
|
|
*
|
||
|
|
* @param s {@code PrintWriter} to use for output
|
||
|
|
* @since 1.1
|
||
|
|
*/
|
||
|
|
public void printStackTrace(PrintWriter s) {
|
||
|
|
printStackTrace(new WrappedPrintWriter(s));
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Wrapper class for PrintStream and PrintWriter to enable a single
|
||
|
|
* implementation of printStackTrace.
|
||
|
|
*/
|
||
|
|
private abstract static class PrintStreamOrWriter {
|
||
|
|
/** Returns the object to be locked when using this StreamOrWriter */
|
||
|
|
abstract Object lock();
|
||
|
|
|
||
|
|
/** Prints the specified string as a line on this StreamOrWriter */
|
||
|
|
abstract void println(Object o);
|
||
|
|
}
|
||
|
|
|
||
|
|
private static class WrappedPrintStream extends PrintStreamOrWriter {
|
||
|
|
private final PrintStream printStream;
|
||
|
|
|
||
|
|
WrappedPrintStream(PrintStream printStream) {
|
||
|
|
this.printStream = printStream;
|
||
|
|
}
|
||
|
|
|
||
|
|
Object lock() {
|
||
|
|
return printStream;
|
||
|
|
}
|
||
|
|
|
||
|
|
void println(Object o) {
|
||
|
|
printStream.println(o);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
private static class WrappedPrintWriter extends PrintStreamOrWriter {
|
||
|
|
private final PrintWriter printWriter;
|
||
|
|
|
||
|
|
WrappedPrintWriter(PrintWriter printWriter) {
|
||
|
|
this.printWriter = printWriter;
|
||
|
|
}
|
||
|
|
|
||
|
|
Object lock() {
|
||
|
|
return printWriter;
|
||
|
|
}
|
||
|
|
|
||
|
|
void println(Object o) {
|
||
|
|
printWriter.println(o);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Fills in the execution stack trace. This method records within this
|
||
|
|
* {@code Throwable} object information about the current state of
|
||
|
|
* the stack frames for the current thread.
|
||
|
|
*
|
||
|
|
* <p>If the stack trace of this {@code Throwable} {@linkplain
|
||
|
|
* Throwable#Throwable(String, Throwable, boolean, boolean) is not
|
||
|
|
* writable}, calling this method has no effect.
|
||
|
|
*
|
||
|
|
* @return a reference to this {@code Throwable} instance.
|
||
|
|
* @see java.lang.Throwable#printStackTrace()
|
||
|
|
*/
|
||
|
|
// Android-changed: Add @NeverInline to keep code size low.
|
||
|
|
@NeverInline
|
||
|
|
public synchronized Throwable fillInStackTrace() {
|
||
|
|
if (stackTrace != null ||
|
||
|
|
backtrace != null /* Out of protocol state */ ) {
|
||
|
|
// Android-changed: Use Android-specific nativeFillInStackTrace.
|
||
|
|
// fillInStackTrace(0);
|
||
|
|
backtrace = nativeFillInStackTrace();
|
||
|
|
// Android-changed: Use libcore.util.EmptyArray for the empty stack trace.
|
||
|
|
// stackTrace = UNASSIGNED_STACK;
|
||
|
|
stackTrace = libcore.util.EmptyArray.STACK_TRACE_ELEMENT;
|
||
|
|
}
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
// Android-changed: Use Android-specific nativeFillInStackTrace.
|
||
|
|
// private native Throwable fillInStackTrace(int dummy);
|
||
|
|
@FastNative
|
||
|
|
private static native Object nativeFillInStackTrace();
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Provides programmatic access to the stack trace information printed by
|
||
|
|
* {@link #printStackTrace()}. Returns an array of stack trace elements,
|
||
|
|
* each representing one stack frame. The zeroth element of the array
|
||
|
|
* (assuming the array's length is non-zero) represents the top of the
|
||
|
|
* stack, which is the last method invocation in the sequence. Typically,
|
||
|
|
* this is the point at which this throwable was created and thrown.
|
||
|
|
* The last element of the array (assuming the array's length is non-zero)
|
||
|
|
* represents the bottom of the stack, which is the first method invocation
|
||
|
|
* in the sequence.
|
||
|
|
*
|
||
|
|
* <p>Some virtual machines may, under some circumstances, omit one
|
||
|
|
* or more stack frames from the stack trace. In the extreme case,
|
||
|
|
* a virtual machine that has no stack trace information concerning
|
||
|
|
* this throwable is permitted to return a zero-length array from this
|
||
|
|
* method. Generally speaking, the array returned by this method will
|
||
|
|
* contain one element for every frame that would be printed by
|
||
|
|
* {@code printStackTrace}. Writes to the returned array do not
|
||
|
|
* affect future calls to this method.
|
||
|
|
*
|
||
|
|
* @return an array of stack trace elements representing the stack trace
|
||
|
|
* pertaining to this throwable.
|
||
|
|
* @since 1.4
|
||
|
|
*/
|
||
|
|
public StackTraceElement[] getStackTrace() {
|
||
|
|
return getOurStackTrace().clone();
|
||
|
|
}
|
||
|
|
|
||
|
|
private synchronized StackTraceElement[] getOurStackTrace() {
|
||
|
|
// Initialize stack trace field with information from
|
||
|
|
// backtrace if this is the first call to this method
|
||
|
|
// Android-changed: Use libcore.util.EmptyArray for the empty stack trace.
|
||
|
|
// if (stackTrace == UNASSIGNED_STACK ||
|
||
|
|
if (stackTrace == libcore.util.EmptyArray.STACK_TRACE_ELEMENT ||
|
||
|
|
(stackTrace == null && backtrace != null) /* Out of protocol state */) {
|
||
|
|
// BEGIN Android-changed: Use Android-specific nativeGetStackTrace.
|
||
|
|
// stackTrace = StackTraceElement.of(this, depth);
|
||
|
|
stackTrace = nativeGetStackTrace(backtrace);
|
||
|
|
backtrace = null;
|
||
|
|
if (stackTrace == null) {
|
||
|
|
return libcore.util.EmptyArray.STACK_TRACE_ELEMENT;
|
||
|
|
}
|
||
|
|
// END Android-changed: Use Android-specific nativeGetStackTrace.
|
||
|
|
} else if (stackTrace == null) {
|
||
|
|
// Android-changed: Use libcore.util.EmptyArray for the empty stack trace.
|
||
|
|
// return UNASSIGNED_STACK;
|
||
|
|
return libcore.util.EmptyArray.STACK_TRACE_ELEMENT;
|
||
|
|
}
|
||
|
|
return stackTrace;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Sets the stack trace elements that will be returned by
|
||
|
|
* {@link #getStackTrace()} and printed by {@link #printStackTrace()}
|
||
|
|
* and related methods.
|
||
|
|
*
|
||
|
|
* This method, which is designed for use by RPC frameworks and other
|
||
|
|
* advanced systems, allows the client to override the default
|
||
|
|
* stack trace that is either generated by {@link #fillInStackTrace()}
|
||
|
|
* when a throwable is constructed or deserialized when a throwable is
|
||
|
|
* read from a serialization stream.
|
||
|
|
*
|
||
|
|
* <p>If the stack trace of this {@code Throwable} {@linkplain
|
||
|
|
* Throwable#Throwable(String, Throwable, boolean, boolean) is not
|
||
|
|
* writable}, calling this method has no effect other than
|
||
|
|
* validating its argument.
|
||
|
|
*
|
||
|
|
* @param stackTrace the stack trace elements to be associated with
|
||
|
|
* this {@code Throwable}. The specified array is copied by this
|
||
|
|
* call; changes in the specified array after the method invocation
|
||
|
|
* returns will have no affect on this {@code Throwable}'s stack
|
||
|
|
* trace.
|
||
|
|
*
|
||
|
|
* @throws NullPointerException if {@code stackTrace} is
|
||
|
|
* {@code null} or if any of the elements of
|
||
|
|
* {@code stackTrace} are {@code null}
|
||
|
|
*
|
||
|
|
* @since 1.4
|
||
|
|
*/
|
||
|
|
public void setStackTrace(StackTraceElement[] stackTrace) {
|
||
|
|
// Validate argument
|
||
|
|
StackTraceElement[] defensiveCopy = stackTrace.clone();
|
||
|
|
for (int i = 0; i < defensiveCopy.length; i++) {
|
||
|
|
if (defensiveCopy[i] == null)
|
||
|
|
throw new NullPointerException("stackTrace[" + i + "]");
|
||
|
|
}
|
||
|
|
|
||
|
|
synchronized (this) {
|
||
|
|
if (this.stackTrace == null && // Immutable stack
|
||
|
|
backtrace == null) // Test for out of protocol state
|
||
|
|
return;
|
||
|
|
this.stackTrace = defensiveCopy;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns the specified element of the stack trace.
|
||
|
|
*
|
||
|
|
* package-protection for use by SharedSecrets.
|
||
|
|
*
|
||
|
|
* @param index index of the element to return.
|
||
|
|
* @throws IndexOutOfBoundsException if {@code index < 0 ||
|
||
|
|
* index >= getStackTraceDepth() }
|
||
|
|
*/
|
||
|
|
// Android-changed: Use Android-specific nativeGetStackTrace.
|
||
|
|
// native StackTraceElement getStackTraceElement(int index);
|
||
|
|
@FastNative
|
||
|
|
private static native StackTraceElement[] nativeGetStackTrace(Object stackState);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Reads a {@code Throwable} from a stream, enforcing
|
||
|
|
* well-formedness constraints on fields. Null entries and
|
||
|
|
* self-pointers are not allowed in the list of {@code
|
||
|
|
* suppressedExceptions}. Null entries are not allowed for stack
|
||
|
|
* trace elements. A null stack trace in the serial form results
|
||
|
|
* in a zero-length stack element array. A single-element stack
|
||
|
|
* trace whose entry is equal to {@code new StackTraceElement("",
|
||
|
|
* "", null, Integer.MIN_VALUE)} results in a {@code null} {@code
|
||
|
|
* stackTrace} field.
|
||
|
|
*
|
||
|
|
* Note that there are no constraints on the value the {@code
|
||
|
|
* cause} field can hold; both {@code null} and {@code this} are
|
||
|
|
* valid values for the field.
|
||
|
|
*
|
||
|
|
* @param s the {@code ObjectInputStream} from which data is read
|
||
|
|
* @throws IOException if an I/O error occurs
|
||
|
|
* @throws ClassNotFoundException if a serialized class cannot be loaded
|
||
|
|
*/
|
||
|
|
@java.io.Serial
|
||
|
|
private void readObject(ObjectInputStream s)
|
||
|
|
throws IOException, ClassNotFoundException {
|
||
|
|
s.defaultReadObject(); // read in all fields
|
||
|
|
|
||
|
|
// Set suppressed exceptions and stack trace elements fields
|
||
|
|
// to marker values until the contents from the serial stream
|
||
|
|
// are validated.
|
||
|
|
List<Throwable> candidateSuppressedExceptions = suppressedExceptions;
|
||
|
|
// Android-changed: Use empty collection in place of SUPPRESSED_SENTINEL.
|
||
|
|
// suppressedExceptions = SUPPRESSED_SENTINEL;
|
||
|
|
suppressedExceptions = Collections.emptyList();
|
||
|
|
|
||
|
|
StackTraceElement[] candidateStackTrace = stackTrace;
|
||
|
|
// Android-changed: Directly create empty array instead of cloning UNASSIGNED_STACK.
|
||
|
|
// stackTrace = UNASSIGNED_STACK.clone();
|
||
|
|
stackTrace = new StackTraceElement[0];
|
||
|
|
|
||
|
|
if (candidateSuppressedExceptions != null) {
|
||
|
|
int suppressedSize = validateSuppressedExceptionsList(candidateSuppressedExceptions);
|
||
|
|
if (suppressedSize > 0) { // Copy valid Throwables to new list
|
||
|
|
var suppList = new ArrayList<Throwable>(Math.min(100, suppressedSize));
|
||
|
|
|
||
|
|
for (Throwable t : candidateSuppressedExceptions) {
|
||
|
|
// Enforce constraints on suppressed exceptions in
|
||
|
|
// case of corrupt or malicious stream.
|
||
|
|
Objects.requireNonNull(t, NULL_CAUSE_MESSAGE);
|
||
|
|
if (t == this)
|
||
|
|
throw new IllegalArgumentException(SELF_SUPPRESSION_MESSAGE);
|
||
|
|
suppList.add(t);
|
||
|
|
}
|
||
|
|
// If there are any invalid suppressed exceptions,
|
||
|
|
// implicitly use the sentinel value assigned earlier.
|
||
|
|
suppressedExceptions = suppList;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
suppressedExceptions = null;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* For zero-length stack traces, use a clone of
|
||
|
|
* UNASSIGNED_STACK rather than UNASSIGNED_STACK itself to
|
||
|
|
* allow identity comparison against UNASSIGNED_STACK in
|
||
|
|
* getOurStackTrace. The identity of UNASSIGNED_STACK in
|
||
|
|
* stackTrace indicates to the getOurStackTrace method that
|
||
|
|
* the stackTrace needs to be constructed from the information
|
||
|
|
* in backtrace.
|
||
|
|
*/
|
||
|
|
if (candidateStackTrace != null) {
|
||
|
|
// Work from a clone of the candidateStackTrace to ensure
|
||
|
|
// consistency of checks.
|
||
|
|
candidateStackTrace = candidateStackTrace.clone();
|
||
|
|
if (candidateStackTrace.length >= 1) {
|
||
|
|
if (candidateStackTrace.length == 1 &&
|
||
|
|
// Check for the marker of an immutable stack trace
|
||
|
|
SentinelHolder.STACK_TRACE_ELEMENT_SENTINEL.equals(candidateStackTrace[0])) {
|
||
|
|
stackTrace = null;
|
||
|
|
} else { // Verify stack trace elements are non-null.
|
||
|
|
for (StackTraceElement ste : candidateStackTrace) {
|
||
|
|
Objects.requireNonNull(ste, "null StackTraceElement in serial stream.");
|
||
|
|
}
|
||
|
|
stackTrace = candidateStackTrace;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// A null stackTrace field in the serial form can result from
|
||
|
|
// an exception serialized without that field in older JDK
|
||
|
|
// releases; treat such exceptions as having empty stack
|
||
|
|
// traces by leaving stackTrace assigned to a clone of
|
||
|
|
// UNASSIGNED_STACK.
|
||
|
|
}
|
||
|
|
|
||
|
|
private int validateSuppressedExceptionsList(List<Throwable> deserSuppressedExceptions)
|
||
|
|
throws IOException {
|
||
|
|
// BEGIN Android-changed: Object class hasn't implemented the module system and getModule().
|
||
|
|
/*
|
||
|
|
if (!Object.class.getModule().
|
||
|
|
equals(deserSuppressedExceptions.getClass().getModule())) {
|
||
|
|
throw new StreamCorruptedException("List implementation not in base module.");
|
||
|
|
} else {
|
||
|
|
*/
|
||
|
|
{
|
||
|
|
// END Android-changed: Object class hasn't implemented the module system and getModule().
|
||
|
|
int size = deserSuppressedExceptions.size();
|
||
|
|
if (size < 0) {
|
||
|
|
throw new StreamCorruptedException("Negative list size reported.");
|
||
|
|
}
|
||
|
|
return size;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Write a {@code Throwable} object to a stream.
|
||
|
|
*
|
||
|
|
* A {@code null} stack trace field is represented in the serial
|
||
|
|
* form as a one-element array whose element is equal to {@code
|
||
|
|
* new StackTraceElement("", "", null, Integer.MIN_VALUE)}.
|
||
|
|
*
|
||
|
|
* @param s the {@code ObjectOutputStream} to which data is written
|
||
|
|
* @throws IOException if an I/O error occurs
|
||
|
|
*/
|
||
|
|
@java.io.Serial
|
||
|
|
private synchronized void writeObject(ObjectOutputStream s)
|
||
|
|
throws IOException {
|
||
|
|
// Ensure that the stackTrace field is initialized to a
|
||
|
|
// non-null value, if appropriate. As of JDK 7, a null stack
|
||
|
|
// trace field is a valid value indicating the stack trace
|
||
|
|
// should not be set.
|
||
|
|
getOurStackTrace();
|
||
|
|
|
||
|
|
StackTraceElement[] oldStackTrace = stackTrace;
|
||
|
|
try {
|
||
|
|
if (stackTrace == null)
|
||
|
|
stackTrace = SentinelHolder.STACK_TRACE_SENTINEL;
|
||
|
|
s.defaultWriteObject();
|
||
|
|
} finally {
|
||
|
|
stackTrace = oldStackTrace;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Appends the specified exception to the exceptions that were
|
||
|
|
* suppressed in order to deliver this exception. This method is
|
||
|
|
* thread-safe and typically called (automatically and implicitly)
|
||
|
|
* by the {@code try}-with-resources statement.
|
||
|
|
*
|
||
|
|
* <p>The suppression behavior is enabled <em>unless</em> disabled
|
||
|
|
* {@linkplain #Throwable(String, Throwable, boolean, boolean) via
|
||
|
|
* a constructor}. When suppression is disabled, this method does
|
||
|
|
* nothing other than to validate its argument.
|
||
|
|
*
|
||
|
|
* <p>Note that when one exception {@linkplain
|
||
|
|
* #initCause(Throwable) causes} another exception, the first
|
||
|
|
* exception is usually caught and then the second exception is
|
||
|
|
* thrown in response. In other words, there is a causal
|
||
|
|
* connection between the two exceptions.
|
||
|
|
*
|
||
|
|
* In contrast, there are situations where two independent
|
||
|
|
* exceptions can be thrown in sibling code blocks, in particular
|
||
|
|
* in the {@code try} block of a {@code try}-with-resources
|
||
|
|
* statement and the compiler-generated {@code finally} block
|
||
|
|
* which closes the resource.
|
||
|
|
*
|
||
|
|
* In these situations, only one of the thrown exceptions can be
|
||
|
|
* propagated. In the {@code try}-with-resources statement, when
|
||
|
|
* there are two such exceptions, the exception originating from
|
||
|
|
* the {@code try} block is propagated and the exception from the
|
||
|
|
* {@code finally} block is added to the list of exceptions
|
||
|
|
* suppressed by the exception from the {@code try} block. As an
|
||
|
|
* exception unwinds the stack, it can accumulate multiple
|
||
|
|
* suppressed exceptions.
|
||
|
|
*
|
||
|
|
* <p>An exception may have suppressed exceptions while also being
|
||
|
|
* caused by another exception. Whether or not an exception has a
|
||
|
|
* cause is semantically known at the time of its creation, unlike
|
||
|
|
* whether or not an exception will suppress other exceptions
|
||
|
|
* which is typically only determined after an exception is
|
||
|
|
* thrown.
|
||
|
|
*
|
||
|
|
* <p>Note that programmer written code is also able to take
|
||
|
|
* advantage of calling this method in situations where there are
|
||
|
|
* multiple sibling exceptions and only one can be propagated.
|
||
|
|
*
|
||
|
|
* @param exception the exception to be added to the list of
|
||
|
|
* suppressed exceptions
|
||
|
|
* @throws IllegalArgumentException if {@code exception} is this
|
||
|
|
* throwable; a throwable cannot suppress itself.
|
||
|
|
* @throws NullPointerException if {@code exception} is {@code null}
|
||
|
|
* @since 1.7
|
||
|
|
*/
|
||
|
|
public final synchronized void addSuppressed(Throwable exception) {
|
||
|
|
if (exception == this)
|
||
|
|
throw new IllegalArgumentException(SELF_SUPPRESSION_MESSAGE, exception);
|
||
|
|
|
||
|
|
Objects.requireNonNull(exception, NULL_CAUSE_MESSAGE);
|
||
|
|
|
||
|
|
if (suppressedExceptions == null) // Suppressed exceptions not recorded
|
||
|
|
return;
|
||
|
|
|
||
|
|
// Android-changed: Use empty collection in place of SUPPRESSED_SENTINEL.
|
||
|
|
// if (suppressedExceptions == SUPPRESSED_SENTINEL)
|
||
|
|
if (suppressedExceptions.isEmpty())
|
||
|
|
suppressedExceptions = new ArrayList<>(1);
|
||
|
|
|
||
|
|
suppressedExceptions.add(exception);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Android-changed: Lazily initialize EMPTY_THROWABLE_ARRAY.
|
||
|
|
// private static final Throwable[] EMPTY_THROWABLE_ARRAY = new Throwable[0];
|
||
|
|
private static Throwable[] EMPTY_THROWABLE_ARRAY;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Returns an array containing all of the exceptions that were
|
||
|
|
* suppressed, typically by the {@code try}-with-resources
|
||
|
|
* statement, in order to deliver this exception.
|
||
|
|
*
|
||
|
|
* If no exceptions were suppressed or {@linkplain
|
||
|
|
* #Throwable(String, Throwable, boolean, boolean) suppression is
|
||
|
|
* disabled}, an empty array is returned. This method is
|
||
|
|
* thread-safe. Writes to the returned array do not affect future
|
||
|
|
* calls to this method.
|
||
|
|
*
|
||
|
|
* @return an array containing all of the exceptions that were
|
||
|
|
* suppressed to deliver this exception.
|
||
|
|
* @since 1.7
|
||
|
|
*/
|
||
|
|
public final synchronized Throwable[] getSuppressed() {
|
||
|
|
// Android-added: Lazily initialize EMPTY_THROWABLE_ARRAY.
|
||
|
|
if (EMPTY_THROWABLE_ARRAY == null) {
|
||
|
|
EMPTY_THROWABLE_ARRAY = new Throwable[0];
|
||
|
|
}
|
||
|
|
|
||
|
|
// Android-changed: Use empty collection in place of SUPPRESSED_SENTINEL.
|
||
|
|
// if (suppressedExceptions == SUPPRESSED_SENTINEL ||
|
||
|
|
// suppressedExceptions == null)
|
||
|
|
if (suppressedExceptions == null || suppressedExceptions.isEmpty())
|
||
|
|
return EMPTY_THROWABLE_ARRAY;
|
||
|
|
else
|
||
|
|
return suppressedExceptions.toArray(EMPTY_THROWABLE_ARRAY);
|
||
|
|
}
|
||
|
|
}
|