The actual result type is {@code Class} - * where {@code |X|} is the erasure of the static type of the - * expression on which {@code getClass} is called. For - * example, no cast is required in this code fragment:
- * - *
- * {@code Number n = 0; }
- * {@code Class c = n.getClass(); }
- *
- * The general contract of {@code hashCode} is: - *
- * As much as is reasonably practical, the hashCode method defined by - * class {@code Object} does return distinct integers for distinct - * objects. (This is typically implemented by converting the internal - * address of the object into an integer, but this implementation - * technique is not required by the - * JavaTM programming language.) - * - * @return a hash code value for this object. - * @see java.lang.Object#equals(java.lang.Object) - * @see java.lang.System#identityHashCode - */ - @JavaScriptBody(args = {}, body = - "if (this.$hashCode) return this.$hashCode;\n" - + "var h = this.computeHashCode__I();\n" - + "return this.$hashCode = h & h;" - ) - public native int hashCode(); - - @JavaScriptBody(args = {}, body = "return Math.random() * Math.pow(2, 32);") - native int computeHashCode(); - - /** - * Indicates whether some other object is "equal to" this one. - *
- * The {@code equals} method implements an equivalence relation - * on non-null object references: - *
- * The {@code equals} method for class {@code Object} implements - * the most discriminating possible equivalence relation on objects; - * that is, for any non-null reference values {@code x} and - * {@code y}, this method returns {@code true} if and only - * if {@code x} and {@code y} refer to the same object - * ({@code x == y} has the value {@code true}). - *
- * Note that it is generally necessary to override the {@code hashCode} - * method whenever this method is overridden, so as to maintain the - * general contract for the {@code hashCode} method, which states - * that equal objects must have equal hash codes. - * - * @param obj the reference object with which to compare. - * @return {@code true} if this object is the same as the obj - * argument; {@code false} otherwise. - * @see #hashCode() - * @see java.util.HashMap - */ - public boolean equals(Object obj) { - return (this == obj); - } - - /** - * Creates and returns a copy of this object. The precise meaning - * of "copy" may depend on the class of the object. The general - * intent is that, for any object {@code x}, the expression: - *
- *- * will be true, and that the expression: - *- * x.clone() != x
- *- * will be {@code true}, but these are not absolute requirements. - * While it is typically the case that: - *- * x.clone().getClass() == x.getClass()
- *- * will be {@code true}, this is not an absolute requirement. - *- * x.clone().equals(x)
- * By convention, the returned object should be obtained by calling - * {@code super.clone}. If a class and all of its superclasses (except - * {@code Object}) obey this convention, it will be the case that - * {@code x.clone().getClass() == x.getClass()}. - *
- * By convention, the object returned by this method should be independent - * of this object (which is being cloned). To achieve this independence, - * it may be necessary to modify one or more fields of the object returned - * by {@code super.clone} before returning it. Typically, this means - * copying any mutable objects that comprise the internal "deep structure" - * of the object being cloned and replacing the references to these - * objects with references to the copies. If a class contains only - * primitive fields or references to immutable objects, then it is usually - * the case that no fields in the object returned by {@code super.clone} - * need to be modified. - *
- * The method {@code clone} for class {@code Object} performs a - * specific cloning operation. First, if the class of this object does - * not implement the interface {@code Cloneable}, then a - * {@code CloneNotSupportedException} is thrown. Note that all arrays - * are considered to implement the interface {@code Cloneable} and that - * the return type of the {@code clone} method of an array type {@code T[]} - * is {@code T[]} where T is any reference or primitive type. - * Otherwise, this method creates a new instance of the class of this - * object and initializes all its fields with exactly the contents of - * the corresponding fields of this object, as if by assignment; the - * contents of the fields are not themselves cloned. Thus, this method - * performs a "shallow copy" of this object, not a "deep copy" operation. - *
- * The class {@code Object} does not itself implement the interface - * {@code Cloneable}, so calling the {@code clone} method on an object - * whose class is {@code Object} will result in throwing an - * exception at run time. - * - * @return a clone of this instance. - * @exception CloneNotSupportedException if the object's class does not - * support the {@code Cloneable} interface. Subclasses - * that override the {@code clone} method can also - * throw this exception to indicate that an instance cannot - * be cloned. - * @see java.lang.Cloneable - */ - protected Object clone() throws CloneNotSupportedException { - Object ret = clone(this); - if (ret == null) { - throw new CloneNotSupportedException(getClass().getName()); - } - return ret; - } - - @JavaScriptBody(args = "self", body = - "\nif (!self.$instOf_java_lang_Cloneable) {" - + "\n return null;" - + "\n} else {" - + "\n var clone = self.constructor(true);" - + "\n var props = Object.getOwnPropertyNames(self);" - + "\n for (var i = 0; i < props.length; i++) {" - + "\n var p = props[i];" - + "\n clone[p] = self[p];" - + "\n };" - + "\n return clone;" - + "\n}" - ) - private static native Object clone(Object self) throws CloneNotSupportedException; - - /** - * Returns a string representation of the object. In general, the - * {@code toString} method returns a string that - * "textually represents" this object. The result should - * be a concise but informative representation that is easy for a - * person to read. - * It is recommended that all subclasses override this method. - *
- * The {@code toString} method for class {@code Object} - * returns a string consisting of the name of the class of which the - * object is an instance, the at-sign character `{@code @}', and - * the unsigned hexadecimal representation of the hash code of the - * object. In other words, this method returns a string equal to the - * value of: - *
- *- * - * @return a string representation of the object. - */ - public String toString() { - return getClass().getName() + "@" + Integer.toHexString(hashCode()); - } - - /** - * Wakes up a single thread that is waiting on this object's - * monitor. If any threads are waiting on this object, one of them - * is chosen to be awakened. The choice is arbitrary and occurs at - * the discretion of the implementation. A thread waits on an object's - * monitor by calling one of the {@code wait} methods. - *- * getClass().getName() + '@' + Integer.toHexString(hashCode()) - *
- * The awakened thread will not be able to proceed until the current - * thread relinquishes the lock on this object. The awakened thread will - * compete in the usual manner with any other threads that might be - * actively competing to synchronize on this object; for example, the - * awakened thread enjoys no reliable privilege or disadvantage in being - * the next thread to lock this object. - *
- * This method should only be called by a thread that is the owner - * of this object's monitor. A thread becomes the owner of the - * object's monitor in one of three ways: - *
- * Only one thread at a time can own an object's monitor. - * - * @exception IllegalMonitorStateException if the current thread is not - * the owner of this object's monitor. - * @see java.lang.Object#notifyAll() - * @see java.lang.Object#wait() - */ - public final native void notify(); - - /** - * Wakes up all threads that are waiting on this object's monitor. A - * thread waits on an object's monitor by calling one of the - * {@code wait} methods. - *
- * The awakened threads will not be able to proceed until the current - * thread relinquishes the lock on this object. The awakened threads - * will compete in the usual manner with any other threads that might - * be actively competing to synchronize on this object; for example, - * the awakened threads enjoy no reliable privilege or disadvantage in - * being the next thread to lock this object. - *
- * This method should only be called by a thread that is the owner - * of this object's monitor. See the {@code notify} method for a - * description of the ways in which a thread can become the owner of - * a monitor. - * - * @exception IllegalMonitorStateException if the current thread is not - * the owner of this object's monitor. - * @see java.lang.Object#notify() - * @see java.lang.Object#wait() - */ - public final native void notifyAll(); - - /** - * Causes the current thread to wait until either another thread invokes the - * {@link java.lang.Object#notify()} method or the - * {@link java.lang.Object#notifyAll()} method for this object, or a - * specified amount of time has elapsed. - *
- * The current thread must own this object's monitor. - *
- * This method causes the current thread (call it T) to - * place itself in the wait set for this object and then to relinquish - * any and all synchronization claims on this object. Thread T - * becomes disabled for thread scheduling purposes and lies dormant - * until one of four things happens: - *
- * A thread can also wake up without being notified, interrupted, or - * timing out, a so-called spurious wakeup. While this will rarely - * occur in practice, applications must guard against it by testing for - * the condition that should have caused the thread to be awakened, and - * continuing to wait if the condition is not satisfied. In other words, - * waits should always occur in loops, like this one: - *
- * synchronized (obj) {
- * while (<condition does not hold>)
- * obj.wait(timeout);
- * ... // Perform action appropriate to condition
- * }
- *
- * (For more information on this topic, see Section 3.2.3 in Doug Lea's
- * "Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
- * 2000), or Item 50 in Joshua Bloch's "Effective Java Programming
- * Language Guide" (Addison-Wesley, 2001).
- *
- * If the current thread is {@linkplain java.lang.Thread#interrupt() - * interrupted} by any thread before or while it is waiting, then an - * {@code InterruptedException} is thrown. This exception is not - * thrown until the lock status of this object has been restored as - * described above. - * - *
- * Note that the {@code wait} method, as it places the current thread - * into the wait set for this object, unlocks only this object; any - * other objects on which the current thread may be synchronized remain - * locked while the thread waits. - *
- * This method should only be called by a thread that is the owner - * of this object's monitor. See the {@code notify} method for a - * description of the ways in which a thread can become the owner of - * a monitor. - * - * @param timeout the maximum time to wait in milliseconds. - * @exception IllegalArgumentException if the value of timeout is - * negative. - * @exception IllegalMonitorStateException if the current thread is not - * the owner of the object's monitor. - * @exception InterruptedException if any thread interrupted the - * current thread before or while the current thread - * was waiting for a notification. The interrupted - * status of the current thread is cleared when - * this exception is thrown. - * @see java.lang.Object#notify() - * @see java.lang.Object#notifyAll() - */ - public final native void wait(long timeout) throws InterruptedException; - - /** - * Causes the current thread to wait until another thread invokes the - * {@link java.lang.Object#notify()} method or the - * {@link java.lang.Object#notifyAll()} method for this object, or - * some other thread interrupts the current thread, or a certain - * amount of real time has elapsed. - *
- * This method is similar to the {@code wait} method of one - * argument, but it allows finer control over the amount of time to - * wait for a notification before giving up. The amount of real time, - * measured in nanoseconds, is given by: - *
- *- *- * 1000000*timeout+nanos
- * In all other respects, this method does the same thing as the - * method {@link #wait(long)} of one argument. In particular, - * {@code wait(0, 0)} means the same thing as {@code wait(0)}. - *
- * The current thread must own this object's monitor. The thread - * releases ownership of this monitor and waits until either of the - * following two conditions has occurred: - *
- * The thread then waits until it can re-obtain ownership of the - * monitor and resumes execution. - *
- * As in the one argument version, interrupts and spurious wakeups are - * possible, and this method should always be used in a loop: - *
- * synchronized (obj) {
- * while (<condition does not hold>)
- * obj.wait(timeout, nanos);
- * ... // Perform action appropriate to condition
- * }
- *
- * This method should only be called by a thread that is the owner
- * of this object's monitor. See the {@code notify} method for a
- * description of the ways in which a thread can become the owner of
- * a monitor.
- *
- * @param timeout the maximum time to wait in milliseconds.
- * @param nanos additional time, in nanoseconds range
- * 0-999999.
- * @exception IllegalArgumentException if the value of timeout is
- * negative or the value of nanos is
- * not in the range 0-999999.
- * @exception IllegalMonitorStateException if the current thread is not
- * the owner of this object's monitor.
- * @exception InterruptedException if any thread interrupted the
- * current thread before or while the current thread
- * was waiting for a notification. The interrupted
- * status of the current thread is cleared when
- * this exception is thrown.
- */
- public final void wait(long timeout, int nanos) throws InterruptedException {
- if (timeout < 0) {
- throw new IllegalArgumentException("timeout value is negative");
- }
-
- if (nanos < 0 || nanos > 999999) {
- throw new IllegalArgumentException(
- "nanosecond timeout value out of range");
- }
-
- if (nanos >= 500000 || (nanos != 0 && timeout == 0)) {
- timeout++;
- }
-
- wait(timeout);
- }
-
- /**
- * Causes the current thread to wait until another thread invokes the
- * {@link java.lang.Object#notify()} method or the
- * {@link java.lang.Object#notifyAll()} method for this object.
- * In other words, this method behaves exactly as if it simply
- * performs the call {@code wait(0)}.
- * - * The current thread must own this object's monitor. The thread - * releases ownership of this monitor and waits until another thread - * notifies threads waiting on this object's monitor to wake up - * either through a call to the {@code notify} method or the - * {@code notifyAll} method. The thread then waits until it can - * re-obtain ownership of the monitor and resumes execution. - *
- * As in the one argument version, interrupts and spurious wakeups are - * possible, and this method should always be used in a loop: - *
- * synchronized (obj) {
- * while (<condition does not hold>)
- * obj.wait();
- * ... // Perform action appropriate to condition
- * }
- *
- * This method should only be called by a thread that is the owner
- * of this object's monitor. See the {@code notify} method for a
- * description of the ways in which a thread can become the owner of
- * a monitor.
- *
- * @exception IllegalMonitorStateException if the current thread is not
- * the owner of the object's monitor.
- * @exception InterruptedException if any thread interrupted the
- * current thread before or while the current thread
- * was waiting for a notification. The interrupted
- * status of the current thread is cleared when
- * this exception is thrown.
- * @see java.lang.Object#notify()
- * @see java.lang.Object#notifyAll()
- */
- public final void wait() throws InterruptedException {
- wait(0);
- }
-
- /**
- * Called by the garbage collector on an object when garbage collection
- * determines that there are no more references to the object.
- * A subclass overrides the {@code finalize} method to dispose of
- * system resources or to perform other cleanup.
- * - * The general contract of {@code finalize} is that it is invoked - * if and when the JavaTM virtual - * machine has determined that there is no longer any - * means by which this object can be accessed by any thread that has - * not yet died, except as a result of an action taken by the - * finalization of some other object or class which is ready to be - * finalized. The {@code finalize} method may take any action, including - * making this object available again to other threads; the usual purpose - * of {@code finalize}, however, is to perform cleanup actions before - * the object is irrevocably discarded. For example, the finalize method - * for an object that represents an input/output connection might perform - * explicit I/O transactions to break the connection before the object is - * permanently discarded. - *
- * The {@code finalize} method of class {@code Object} performs no - * special action; it simply returns normally. Subclasses of - * {@code Object} may override this definition. - *
- * The Java programming language does not guarantee which thread will - * invoke the {@code finalize} method for any given object. It is - * guaranteed, however, that the thread that invokes finalize will not - * be holding any user-visible synchronization locks when finalize is - * invoked. If an uncaught exception is thrown by the finalize method, - * the exception is ignored and finalization of that object terminates. - *
- * After the {@code finalize} method has been invoked for an object, no - * further action is taken until the Java virtual machine has again - * determined that there is no longer any means by which this object can - * be accessed by any thread that has not yet died, including possible - * actions by other objects or classes which are ready to be finalized, - * at which point the object may be discarded. - *
- * The {@code finalize} method is never invoked more than once by a Java - * virtual machine for any given object. - *
- * Any exception thrown by the {@code finalize} method causes - * the finalization of this object to be halted, but is otherwise - * ignored. - * - * @throws Throwable the {@code Exception} raised by this method - */ - protected void finalize() throws Throwable { } -}