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/*
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* Copyright (c) 1994, 2010, 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 org.apidesign.bck2brwsr.core.JavaScriptBody;
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import org.apidesign.bck2brwsr.core.JavaScriptPrototype;
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/**
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* Class {@code Object} is the root of the class hierarchy.
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* Every class has {@code Object} as a superclass. All objects,
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* including arrays, implement the methods of this class.
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*
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* @author unascribed
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* @see java.lang.Class
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* @since JDK1.0
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*/
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@JavaScriptPrototype(container = "Object.prototype", prototype = "new Object")
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public class Object {
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static {
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Class.registerNatives();
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Class.registerToString();
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}
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/**
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* Returns the runtime class of this {@code Object}. The returned
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* {@code Class} object is the object that is locked by {@code
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* static synchronized} methods of the represented class.
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*
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* <p><b>The actual result type is {@code Class<? extends |X|>}
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* where {@code |X|} is the erasure of the static type of the
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* expression on which {@code getClass} is called.</b> For
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* example, no cast is required in this code fragment:</p>
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*
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* <p>
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* {@code Number n = 0; }<br>
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* {@code Class<? extends Number> c = n.getClass(); }
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* </p>
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*
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* @return The {@code Class} object that represents the runtime
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* class of this object.
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* @see Class Literals, section 15.8.2 of
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* <cite>The Java™ Language Specification</cite>.
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*/
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public final Class<?> getClass() {
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Class<?> c = Class.classFor(this);
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return c == null ? Object.class : c;
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}
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/**
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* Returns a hash code value for the object. This method is
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* supported for the benefit of hash tables such as those provided by
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* {@link java.util.HashMap}.
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* <p>
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* The general contract of {@code hashCode} is:
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* <ul>
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* <li>Whenever it is invoked on the same object more than once during
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* an execution of a Java application, the {@code hashCode} method
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* must consistently return the same integer, provided no information
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* used in {@code equals} comparisons on the object is modified.
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* This integer need not remain consistent from one execution of an
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* application to another execution of the same application.
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* <li>If two objects are equal according to the {@code equals(Object)}
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* method, then calling the {@code hashCode} method on each of
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* the two objects must produce the same integer result.
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* <li>It is <em>not</em> required that if two objects are unequal
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* according to the {@link java.lang.Object#equals(java.lang.Object)}
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* method, then calling the {@code hashCode} method on each of the
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* two objects must produce distinct integer results. However, the
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* programmer should be aware that producing distinct integer results
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* for unequal objects may improve the performance of hash tables.
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* </ul>
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* <p>
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* As much as is reasonably practical, the hashCode method defined by
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* class {@code Object} does return distinct integers for distinct
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* objects. (This is typically implemented by converting the internal
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* address of the object into an integer, but this implementation
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* technique is not required by the
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* Java<font size="-2"><sup>TM</sup></font> programming language.)
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*
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* @return a hash code value for this object.
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* @see java.lang.Object#equals(java.lang.Object)
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* @see java.lang.System#identityHashCode
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*/
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public int hashCode() {
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return Class.defaultHashCode(this);
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}
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/**
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* Indicates whether some other object is "equal to" this one.
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* <p>
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* The {@code equals} method implements an equivalence relation
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* on non-null object references:
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* <ul>
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* <li>It is <i>reflexive</i>: for any non-null reference value
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* {@code x}, {@code x.equals(x)} should return
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* {@code true}.
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* <li>It is <i>symmetric</i>: for any non-null reference values
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* {@code x} and {@code y}, {@code x.equals(y)}
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* should return {@code true} if and only if
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* {@code y.equals(x)} returns {@code true}.
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* <li>It is <i>transitive</i>: for any non-null reference values
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* {@code x}, {@code y}, and {@code z}, if
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* {@code x.equals(y)} returns {@code true} and
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* {@code y.equals(z)} returns {@code true}, then
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* {@code x.equals(z)} should return {@code true}.
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* <li>It is <i>consistent</i>: for any non-null reference values
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* {@code x} and {@code y}, multiple invocations of
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* {@code x.equals(y)} consistently return {@code true}
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* or consistently return {@code false}, provided no
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* information used in {@code equals} comparisons on the
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* objects is modified.
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* <li>For any non-null reference value {@code x},
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* {@code x.equals(null)} should return {@code false}.
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* </ul>
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* <p>
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* The {@code equals} method for class {@code Object} implements
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* the most discriminating possible equivalence relation on objects;
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* that is, for any non-null reference values {@code x} and
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* {@code y}, this method returns {@code true} if and only
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* if {@code x} and {@code y} refer to the same object
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* ({@code x == y} has the value {@code true}).
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* <p>
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* Note that it is generally necessary to override the {@code hashCode}
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* method whenever this method is overridden, so as to maintain the
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* general contract for the {@code hashCode} method, which states
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* that equal objects must have equal hash codes.
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*
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* @param obj the reference object with which to compare.
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* @return {@code true} if this object is the same as the obj
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* argument; {@code false} otherwise.
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* @see #hashCode()
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* @see java.util.HashMap
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*/
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public boolean equals(Object obj) {
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return (this == obj);
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}
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/**
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* Creates and returns a copy of this object. The precise meaning
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* of "copy" may depend on the class of the object. The general
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* intent is that, for any object {@code x}, the expression:
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* <blockquote>
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* <pre>
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* x.clone() != x</pre></blockquote>
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* will be true, and that the expression:
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* <blockquote>
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* <pre>
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* x.clone().getClass() == x.getClass()</pre></blockquote>
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* will be {@code true}, but these are not absolute requirements.
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* While it is typically the case that:
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* <blockquote>
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* <pre>
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* x.clone().equals(x)</pre></blockquote>
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* will be {@code true}, this is not an absolute requirement.
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* <p>
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* By convention, the returned object should be obtained by calling
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* {@code super.clone}. If a class and all of its superclasses (except
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* {@code Object}) obey this convention, it will be the case that
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* {@code x.clone().getClass() == x.getClass()}.
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* <p>
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* By convention, the object returned by this method should be independent
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* of this object (which is being cloned). To achieve this independence,
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* it may be necessary to modify one or more fields of the object returned
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* by {@code super.clone} before returning it. Typically, this means
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* copying any mutable objects that comprise the internal "deep structure"
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* of the object being cloned and replacing the references to these
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* objects with references to the copies. If a class contains only
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* primitive fields or references to immutable objects, then it is usually
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* the case that no fields in the object returned by {@code super.clone}
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* need to be modified.
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* <p>
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* The method {@code clone} for class {@code Object} performs a
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* specific cloning operation. First, if the class of this object does
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* not implement the interface {@code Cloneable}, then a
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* {@code CloneNotSupportedException} is thrown. Note that all arrays
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* are considered to implement the interface {@code Cloneable} and that
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* the return type of the {@code clone} method of an array type {@code T[]}
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* is {@code T[]} where T is any reference or primitive type.
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* Otherwise, this method creates a new instance of the class of this
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* object and initializes all its fields with exactly the contents of
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* the corresponding fields of this object, as if by assignment; the
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* contents of the fields are not themselves cloned. Thus, this method
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* performs a "shallow copy" of this object, not a "deep copy" operation.
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* <p>
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* The class {@code Object} does not itself implement the interface
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* {@code Cloneable}, so calling the {@code clone} method on an object
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* whose class is {@code Object} will result in throwing an
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* exception at run time.
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*
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* @return a clone of this instance.
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* @exception CloneNotSupportedException if the object's class does not
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* support the {@code Cloneable} interface. Subclasses
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* that override the {@code clone} method can also
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* throw this exception to indicate that an instance cannot
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* be cloned.
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* @see java.lang.Cloneable
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*/
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protected Object clone() throws CloneNotSupportedException {
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Object ret = Class.clone(this);
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if (ret == null) {
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throw new CloneNotSupportedException(getClass().getName());
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}
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return ret;
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}
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/**
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* Returns a string representation of the object. In general, the
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* {@code toString} method returns a string that
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* "textually represents" this object. The result should
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* be a concise but informative representation that is easy for a
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* person to read.
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* It is recommended that all subclasses override this method.
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* <p>
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* The {@code toString} method for class {@code Object}
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* returns a string consisting of the name of the class of which the
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* object is an instance, the at-sign character `{@code @}', and
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* the unsigned hexadecimal representation of the hash code of the
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* object. In other words, this method returns a string equal to the
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* value of:
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* <blockquote>
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* <pre>
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* getClass().getName() + '@' + Integer.toHexString(hashCode())
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* </pre></blockquote>
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*
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* @return a string representation of the object.
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*/
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public String toString() {
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return getClass().getName() + "@" + Integer.toHexString(hashCode());
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}
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/**
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* Wakes up a single thread that is waiting on this object's
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* monitor. If any threads are waiting on this object, one of them
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* is chosen to be awakened. The choice is arbitrary and occurs at
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* the discretion of the implementation. A thread waits on an object's
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* monitor by calling one of the {@code wait} methods.
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* <p>
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* The awakened thread will not be able to proceed until the current
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* thread relinquishes the lock on this object. The awakened thread will
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* compete in the usual manner with any other threads that might be
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* actively competing to synchronize on this object; for example, the
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* awakened thread enjoys no reliable privilege or disadvantage in being
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* the next thread to lock this object.
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* <p>
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* This method should only be called by a thread that is the owner
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* of this object's monitor. A thread becomes the owner of the
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* object's monitor in one of three ways:
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* <ul>
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* <li>By executing a synchronized instance method of that object.
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* <li>By executing the body of a {@code synchronized} statement
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* that synchronizes on the object.
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* <li>For objects of type {@code Class,} by executing a
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* synchronized static method of that class.
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* </ul>
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* <p>
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* Only one thread at a time can own an object's monitor.
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*
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* @exception IllegalMonitorStateException if the current thread is not
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* the owner of this object's monitor.
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* @see java.lang.Object#notifyAll()
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* @see java.lang.Object#wait()
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*/
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public final void notify() {
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}
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/**
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* Wakes up all threads that are waiting on this object's monitor. A
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* thread waits on an object's monitor by calling one of the
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* {@code wait} methods.
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|
293 |
* <p>
|
jaroslav@49
|
294 |
* The awakened threads will not be able to proceed until the current
|
jaroslav@49
|
295 |
* thread relinquishes the lock on this object. The awakened threads
|
jaroslav@49
|
296 |
* will compete in the usual manner with any other threads that might
|
jaroslav@49
|
297 |
* be actively competing to synchronize on this object; for example,
|
jaroslav@49
|
298 |
* the awakened threads enjoy no reliable privilege or disadvantage in
|
jaroslav@49
|
299 |
* being the next thread to lock this object.
|
jaroslav@49
|
300 |
* <p>
|
jaroslav@49
|
301 |
* This method should only be called by a thread that is the owner
|
jaroslav@49
|
302 |
* of this object's monitor. See the {@code notify} method for a
|
jaroslav@49
|
303 |
* description of the ways in which a thread can become the owner of
|
jaroslav@49
|
304 |
* a monitor.
|
jaroslav@49
|
305 |
*
|
jaroslav@49
|
306 |
* @exception IllegalMonitorStateException if the current thread is not
|
jaroslav@49
|
307 |
* the owner of this object's monitor.
|
jaroslav@49
|
308 |
* @see java.lang.Object#notify()
|
jaroslav@49
|
309 |
* @see java.lang.Object#wait()
|
jaroslav@49
|
310 |
*/
|
jaroslav@1285
|
311 |
public final void notifyAll() {
|
jaroslav@1285
|
312 |
}
|
jaroslav@49
|
313 |
|
jaroslav@49
|
314 |
/**
|
jaroslav@49
|
315 |
* Causes the current thread to wait until either another thread invokes the
|
jaroslav@49
|
316 |
* {@link java.lang.Object#notify()} method or the
|
jaroslav@49
|
317 |
* {@link java.lang.Object#notifyAll()} method for this object, or a
|
jaroslav@49
|
318 |
* specified amount of time has elapsed.
|
jaroslav@49
|
319 |
* <p>
|
jaroslav@49
|
320 |
* The current thread must own this object's monitor.
|
jaroslav@49
|
321 |
* <p>
|
jaroslav@49
|
322 |
* This method causes the current thread (call it <var>T</var>) to
|
jaroslav@49
|
323 |
* place itself in the wait set for this object and then to relinquish
|
jaroslav@49
|
324 |
* any and all synchronization claims on this object. Thread <var>T</var>
|
jaroslav@49
|
325 |
* becomes disabled for thread scheduling purposes and lies dormant
|
jaroslav@49
|
326 |
* until one of four things happens:
|
jaroslav@49
|
327 |
* <ul>
|
jaroslav@49
|
328 |
* <li>Some other thread invokes the {@code notify} method for this
|
jaroslav@49
|
329 |
* object and thread <var>T</var> happens to be arbitrarily chosen as
|
jaroslav@49
|
330 |
* the thread to be awakened.
|
jaroslav@49
|
331 |
* <li>Some other thread invokes the {@code notifyAll} method for this
|
jaroslav@49
|
332 |
* object.
|
jaroslav@49
|
333 |
* <li>Some other thread {@linkplain Thread#interrupt() interrupts}
|
jaroslav@49
|
334 |
* thread <var>T</var>.
|
jaroslav@49
|
335 |
* <li>The specified amount of real time has elapsed, more or less. If
|
jaroslav@49
|
336 |
* {@code timeout} is zero, however, then real time is not taken into
|
jaroslav@49
|
337 |
* consideration and the thread simply waits until notified.
|
jaroslav@49
|
338 |
* </ul>
|
jaroslav@49
|
339 |
* The thread <var>T</var> is then removed from the wait set for this
|
jaroslav@49
|
340 |
* object and re-enabled for thread scheduling. It then competes in the
|
jaroslav@49
|
341 |
* usual manner with other threads for the right to synchronize on the
|
jaroslav@49
|
342 |
* object; once it has gained control of the object, all its
|
jaroslav@49
|
343 |
* synchronization claims on the object are restored to the status quo
|
jaroslav@49
|
344 |
* ante - that is, to the situation as of the time that the {@code wait}
|
jaroslav@49
|
345 |
* method was invoked. Thread <var>T</var> then returns from the
|
jaroslav@49
|
346 |
* invocation of the {@code wait} method. Thus, on return from the
|
jaroslav@49
|
347 |
* {@code wait} method, the synchronization state of the object and of
|
jaroslav@49
|
348 |
* thread {@code T} is exactly as it was when the {@code wait} method
|
jaroslav@49
|
349 |
* was invoked.
|
jaroslav@49
|
350 |
* <p>
|
jaroslav@49
|
351 |
* A thread can also wake up without being notified, interrupted, or
|
jaroslav@49
|
352 |
* timing out, a so-called <i>spurious wakeup</i>. While this will rarely
|
jaroslav@49
|
353 |
* occur in practice, applications must guard against it by testing for
|
jaroslav@49
|
354 |
* the condition that should have caused the thread to be awakened, and
|
jaroslav@49
|
355 |
* continuing to wait if the condition is not satisfied. In other words,
|
jaroslav@49
|
356 |
* waits should always occur in loops, like this one:
|
jaroslav@49
|
357 |
* <pre>
|
jaroslav@49
|
358 |
* synchronized (obj) {
|
jaroslav@49
|
359 |
* while (<condition does not hold>)
|
jaroslav@49
|
360 |
* obj.wait(timeout);
|
jaroslav@49
|
361 |
* ... // Perform action appropriate to condition
|
jaroslav@49
|
362 |
* }
|
jaroslav@49
|
363 |
* </pre>
|
jaroslav@49
|
364 |
* (For more information on this topic, see Section 3.2.3 in Doug Lea's
|
jaroslav@49
|
365 |
* "Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
|
jaroslav@49
|
366 |
* 2000), or Item 50 in Joshua Bloch's "Effective Java Programming
|
jaroslav@49
|
367 |
* Language Guide" (Addison-Wesley, 2001).
|
jaroslav@49
|
368 |
*
|
jaroslav@49
|
369 |
* <p>If the current thread is {@linkplain java.lang.Thread#interrupt()
|
jaroslav@49
|
370 |
* interrupted} by any thread before or while it is waiting, then an
|
jaroslav@49
|
371 |
* {@code InterruptedException} is thrown. This exception is not
|
jaroslav@49
|
372 |
* thrown until the lock status of this object has been restored as
|
jaroslav@49
|
373 |
* described above.
|
jaroslav@49
|
374 |
*
|
jaroslav@49
|
375 |
* <p>
|
jaroslav@49
|
376 |
* Note that the {@code wait} method, as it places the current thread
|
jaroslav@49
|
377 |
* into the wait set for this object, unlocks only this object; any
|
jaroslav@49
|
378 |
* other objects on which the current thread may be synchronized remain
|
jaroslav@49
|
379 |
* locked while the thread waits.
|
jaroslav@49
|
380 |
* <p>
|
jaroslav@49
|
381 |
* This method should only be called by a thread that is the owner
|
jaroslav@49
|
382 |
* of this object's monitor. See the {@code notify} method for a
|
jaroslav@49
|
383 |
* description of the ways in which a thread can become the owner of
|
jaroslav@49
|
384 |
* a monitor.
|
jaroslav@49
|
385 |
*
|
jaroslav@49
|
386 |
* @param timeout the maximum time to wait in milliseconds.
|
jaroslav@49
|
387 |
* @exception IllegalArgumentException if the value of timeout is
|
jaroslav@49
|
388 |
* negative.
|
jaroslav@49
|
389 |
* @exception IllegalMonitorStateException if the current thread is not
|
jaroslav@49
|
390 |
* the owner of the object's monitor.
|
jaroslav@49
|
391 |
* @exception InterruptedException if any thread interrupted the
|
jaroslav@49
|
392 |
* current thread before or while the current thread
|
jaroslav@49
|
393 |
* was waiting for a notification. The <i>interrupted
|
jaroslav@49
|
394 |
* status</i> of the current thread is cleared when
|
jaroslav@49
|
395 |
* this exception is thrown.
|
jaroslav@49
|
396 |
* @see java.lang.Object#notify()
|
jaroslav@49
|
397 |
* @see java.lang.Object#notifyAll()
|
jaroslav@49
|
398 |
*/
|
jaroslav@1285
|
399 |
public final void wait(long timeout) throws InterruptedException {
|
jaroslav@1285
|
400 |
throw new InterruptedException();
|
jaroslav@1285
|
401 |
}
|
jaroslav@49
|
402 |
|
jaroslav@49
|
403 |
/**
|
jaroslav@49
|
404 |
* Causes the current thread to wait until another thread invokes the
|
jaroslav@49
|
405 |
* {@link java.lang.Object#notify()} method or the
|
jaroslav@49
|
406 |
* {@link java.lang.Object#notifyAll()} method for this object, or
|
jaroslav@49
|
407 |
* some other thread interrupts the current thread, or a certain
|
jaroslav@49
|
408 |
* amount of real time has elapsed.
|
jaroslav@49
|
409 |
* <p>
|
jaroslav@49
|
410 |
* This method is similar to the {@code wait} method of one
|
jaroslav@49
|
411 |
* argument, but it allows finer control over the amount of time to
|
jaroslav@49
|
412 |
* wait for a notification before giving up. The amount of real time,
|
jaroslav@49
|
413 |
* measured in nanoseconds, is given by:
|
jaroslav@49
|
414 |
* <blockquote>
|
jaroslav@49
|
415 |
* <pre>
|
jaroslav@49
|
416 |
* 1000000*timeout+nanos</pre></blockquote>
|
jaroslav@49
|
417 |
* <p>
|
jaroslav@49
|
418 |
* In all other respects, this method does the same thing as the
|
jaroslav@49
|
419 |
* method {@link #wait(long)} of one argument. In particular,
|
jaroslav@49
|
420 |
* {@code wait(0, 0)} means the same thing as {@code wait(0)}.
|
jaroslav@49
|
421 |
* <p>
|
jaroslav@49
|
422 |
* The current thread must own this object's monitor. The thread
|
jaroslav@49
|
423 |
* releases ownership of this monitor and waits until either of the
|
jaroslav@49
|
424 |
* following two conditions has occurred:
|
jaroslav@49
|
425 |
* <ul>
|
jaroslav@49
|
426 |
* <li>Another thread notifies threads waiting on this object's monitor
|
jaroslav@49
|
427 |
* to wake up either through a call to the {@code notify} method
|
jaroslav@49
|
428 |
* or the {@code notifyAll} method.
|
jaroslav@49
|
429 |
* <li>The timeout period, specified by {@code timeout}
|
jaroslav@49
|
430 |
* milliseconds plus {@code nanos} nanoseconds arguments, has
|
jaroslav@49
|
431 |
* elapsed.
|
jaroslav@49
|
432 |
* </ul>
|
jaroslav@49
|
433 |
* <p>
|
jaroslav@49
|
434 |
* The thread then waits until it can re-obtain ownership of the
|
jaroslav@49
|
435 |
* monitor and resumes execution.
|
jaroslav@49
|
436 |
* <p>
|
jaroslav@49
|
437 |
* As in the one argument version, interrupts and spurious wakeups are
|
jaroslav@49
|
438 |
* possible, and this method should always be used in a loop:
|
jaroslav@49
|
439 |
* <pre>
|
jaroslav@49
|
440 |
* synchronized (obj) {
|
jaroslav@49
|
441 |
* while (<condition does not hold>)
|
jaroslav@49
|
442 |
* obj.wait(timeout, nanos);
|
jaroslav@49
|
443 |
* ... // Perform action appropriate to condition
|
jaroslav@49
|
444 |
* }
|
jaroslav@49
|
445 |
* </pre>
|
jaroslav@49
|
446 |
* This method should only be called by a thread that is the owner
|
jaroslav@49
|
447 |
* of this object's monitor. See the {@code notify} method for a
|
jaroslav@49
|
448 |
* description of the ways in which a thread can become the owner of
|
jaroslav@49
|
449 |
* a monitor.
|
jaroslav@49
|
450 |
*
|
jaroslav@49
|
451 |
* @param timeout the maximum time to wait in milliseconds.
|
jaroslav@49
|
452 |
* @param nanos additional time, in nanoseconds range
|
jaroslav@49
|
453 |
* 0-999999.
|
jaroslav@49
|
454 |
* @exception IllegalArgumentException if the value of timeout is
|
jaroslav@49
|
455 |
* negative or the value of nanos is
|
jaroslav@49
|
456 |
* not in the range 0-999999.
|
jaroslav@49
|
457 |
* @exception IllegalMonitorStateException if the current thread is not
|
jaroslav@49
|
458 |
* the owner of this object's monitor.
|
jaroslav@49
|
459 |
* @exception InterruptedException if any thread interrupted the
|
jaroslav@49
|
460 |
* current thread before or while the current thread
|
jaroslav@49
|
461 |
* was waiting for a notification. The <i>interrupted
|
jaroslav@49
|
462 |
* status</i> of the current thread is cleared when
|
jaroslav@49
|
463 |
* this exception is thrown.
|
jaroslav@49
|
464 |
*/
|
jaroslav@49
|
465 |
public final void wait(long timeout, int nanos) throws InterruptedException {
|
jaroslav@1285
|
466 |
throw new InterruptedException();
|
jaroslav@49
|
467 |
}
|
jaroslav@49
|
468 |
|
jaroslav@49
|
469 |
/**
|
jaroslav@49
|
470 |
* Causes the current thread to wait until another thread invokes the
|
jaroslav@49
|
471 |
* {@link java.lang.Object#notify()} method or the
|
jaroslav@49
|
472 |
* {@link java.lang.Object#notifyAll()} method for this object.
|
jaroslav@49
|
473 |
* In other words, this method behaves exactly as if it simply
|
jaroslav@49
|
474 |
* performs the call {@code wait(0)}.
|
jaroslav@49
|
475 |
* <p>
|
jaroslav@49
|
476 |
* The current thread must own this object's monitor. The thread
|
jaroslav@49
|
477 |
* releases ownership of this monitor and waits until another thread
|
jaroslav@49
|
478 |
* notifies threads waiting on this object's monitor to wake up
|
jaroslav@49
|
479 |
* either through a call to the {@code notify} method or the
|
jaroslav@49
|
480 |
* {@code notifyAll} method. The thread then waits until it can
|
jaroslav@49
|
481 |
* re-obtain ownership of the monitor and resumes execution.
|
jaroslav@49
|
482 |
* <p>
|
jaroslav@49
|
483 |
* As in the one argument version, interrupts and spurious wakeups are
|
jaroslav@49
|
484 |
* possible, and this method should always be used in a loop:
|
jaroslav@49
|
485 |
* <pre>
|
jaroslav@49
|
486 |
* synchronized (obj) {
|
jaroslav@49
|
487 |
* while (<condition does not hold>)
|
jaroslav@49
|
488 |
* obj.wait();
|
jaroslav@49
|
489 |
* ... // Perform action appropriate to condition
|
jaroslav@49
|
490 |
* }
|
jaroslav@49
|
491 |
* </pre>
|
jaroslav@49
|
492 |
* This method should only be called by a thread that is the owner
|
jaroslav@49
|
493 |
* of this object's monitor. See the {@code notify} method for a
|
jaroslav@49
|
494 |
* description of the ways in which a thread can become the owner of
|
jaroslav@49
|
495 |
* a monitor.
|
jaroslav@49
|
496 |
*
|
jaroslav@49
|
497 |
* @exception IllegalMonitorStateException if the current thread is not
|
jaroslav@49
|
498 |
* the owner of the object's monitor.
|
jaroslav@49
|
499 |
* @exception InterruptedException if any thread interrupted the
|
jaroslav@49
|
500 |
* current thread before or while the current thread
|
jaroslav@49
|
501 |
* was waiting for a notification. The <i>interrupted
|
jaroslav@49
|
502 |
* status</i> of the current thread is cleared when
|
jaroslav@49
|
503 |
* this exception is thrown.
|
jaroslav@49
|
504 |
* @see java.lang.Object#notify()
|
jaroslav@49
|
505 |
* @see java.lang.Object#notifyAll()
|
jaroslav@49
|
506 |
*/
|
jaroslav@49
|
507 |
public final void wait() throws InterruptedException {
|
jaroslav@1285
|
508 |
throw new InterruptedException();
|
jaroslav@49
|
509 |
}
|
jaroslav@49
|
510 |
|
jaroslav@49
|
511 |
/**
|
jaroslav@49
|
512 |
* Called by the garbage collector on an object when garbage collection
|
jaroslav@49
|
513 |
* determines that there are no more references to the object.
|
jaroslav@49
|
514 |
* A subclass overrides the {@code finalize} method to dispose of
|
jaroslav@49
|
515 |
* system resources or to perform other cleanup.
|
jaroslav@49
|
516 |
* <p>
|
jaroslav@49
|
517 |
* The general contract of {@code finalize} is that it is invoked
|
jaroslav@49
|
518 |
* if and when the Java<font size="-2"><sup>TM</sup></font> virtual
|
jaroslav@49
|
519 |
* machine has determined that there is no longer any
|
jaroslav@49
|
520 |
* means by which this object can be accessed by any thread that has
|
jaroslav@49
|
521 |
* not yet died, except as a result of an action taken by the
|
jaroslav@49
|
522 |
* finalization of some other object or class which is ready to be
|
jaroslav@49
|
523 |
* finalized. The {@code finalize} method may take any action, including
|
jaroslav@49
|
524 |
* making this object available again to other threads; the usual purpose
|
jaroslav@49
|
525 |
* of {@code finalize}, however, is to perform cleanup actions before
|
jaroslav@49
|
526 |
* the object is irrevocably discarded. For example, the finalize method
|
jaroslav@49
|
527 |
* for an object that represents an input/output connection might perform
|
jaroslav@49
|
528 |
* explicit I/O transactions to break the connection before the object is
|
jaroslav@49
|
529 |
* permanently discarded.
|
jaroslav@49
|
530 |
* <p>
|
jaroslav@49
|
531 |
* The {@code finalize} method of class {@code Object} performs no
|
jaroslav@49
|
532 |
* special action; it simply returns normally. Subclasses of
|
jaroslav@49
|
533 |
* {@code Object} may override this definition.
|
jaroslav@49
|
534 |
* <p>
|
jaroslav@49
|
535 |
* The Java programming language does not guarantee which thread will
|
jaroslav@49
|
536 |
* invoke the {@code finalize} method for any given object. It is
|
jaroslav@49
|
537 |
* guaranteed, however, that the thread that invokes finalize will not
|
jaroslav@49
|
538 |
* be holding any user-visible synchronization locks when finalize is
|
jaroslav@49
|
539 |
* invoked. If an uncaught exception is thrown by the finalize method,
|
jaroslav@49
|
540 |
* the exception is ignored and finalization of that object terminates.
|
jaroslav@49
|
541 |
* <p>
|
jaroslav@49
|
542 |
* After the {@code finalize} method has been invoked for an object, no
|
jaroslav@49
|
543 |
* further action is taken until the Java virtual machine has again
|
jaroslav@49
|
544 |
* determined that there is no longer any means by which this object can
|
jaroslav@49
|
545 |
* be accessed by any thread that has not yet died, including possible
|
jaroslav@49
|
546 |
* actions by other objects or classes which are ready to be finalized,
|
jaroslav@49
|
547 |
* at which point the object may be discarded.
|
jaroslav@49
|
548 |
* <p>
|
jaroslav@49
|
549 |
* The {@code finalize} method is never invoked more than once by a Java
|
jaroslav@49
|
550 |
* virtual machine for any given object.
|
jaroslav@49
|
551 |
* <p>
|
jaroslav@49
|
552 |
* Any exception thrown by the {@code finalize} method causes
|
jaroslav@49
|
553 |
* the finalization of this object to be halted, but is otherwise
|
jaroslav@49
|
554 |
* ignored.
|
jaroslav@49
|
555 |
*
|
jaroslav@49
|
556 |
* @throws Throwable the {@code Exception} raised by this method
|
jaroslav@49
|
557 |
*/
|
jaroslav@49
|
558 |
protected void finalize() throws Throwable { }
|
jaroslav@49
|
559 |
}
|