package java.lang; import ej.annotation.Nullable; /** * Class {@code Object} is the root of the class hierarchy. Every class has {@code Object} as a * superclass. All objects, including arrays, implement the methods of this class. * * @see java.lang.Class */ public class Object { /** * Creates a new Object. */ public Object() { throw new RuntimeException(); } /** * 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:
* * 
     * x.clone() != x
     *
* *
will be true, and that the expression:
* * 
     * x.clone().getClass() == x.getClass()
     *
* *
will be {@code true}, but these are not absolute requirements. While it is * typically the case that:
* * 
     * x.clone().equals(x)
     *
* *
will be {@code true}, this is not an absolute requirement. *

* 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 { throw new RuntimeException(); } /** * 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(@Nullable Object obj) { throw new RuntimeException(); } /** * Returns the runtime class of this {@code Object}. The returned {@code Class} object is the object * that is locked by {@code static synchronized} methods of the represented class. * *

* 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(); } *

* * @return The {@code Class} object that represents the runtime class of this object. * @see Class Literals, section 15.8.2 of The Java™ Language Specification. */ public final Class getClass() { throw new RuntimeException(); } /** * Returns a hash code value for the object. This method is supported for the benefit of hash tables * such as those provided by {@link java.util.HashMap}. *

* 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 */ public int hashCode() { throw new RuntimeException(); } /** * 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. *

* 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 void notify() { throw new RuntimeException(); } /** * 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 void notifyAll() { throw new RuntimeException(); } /** * 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:

* * 
     * getClass().getName() + '@' + Integer.toHexString(hashCode())
     *
* *
* * @return a string representation of the object. */ public String toString() { throw new RuntimeException(); } /** * 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 { throw new RuntimeException(); } /** * 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: *

* The thread T is then removed from the wait set for this object and re-enabled for * thread scheduling. It then competes in the usual manner with other threads for the right to * synchronize on the object; once it has gained control of the object, all its synchronization * claims on the object are restored to the status quo ante - that is, to the situation as of the * time that the {@code wait} method was invoked. Thread T then returns from the * invocation of the {@code wait} method. Thus, on return from the {@code wait} method, the * synchronization state of the object and of thread {@code T} is exactly as it was when the * {@code wait} method was invoked. *

* 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 void wait(long timeout) throws InterruptedException { throw new RuntimeException(); } /** * 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 { throw new RuntimeException(); } }