/* * * * Copyright 1990-2009 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 only, as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License version 2 for more details (a copy is * included at /legal/license.txt). * * You should have received a copy of the GNU General Public License * version 2 along with this work; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA * 02110-1301 USA * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa * Clara, CA 95054 or visit www.sun.com if you need additional * information or have any questions. */ package java.lang; import com.jopdesign.sys.Native; /** * Class <code>Object</code> is the root of the class hierarchy. * Every class has <code>Object</code> as a superclass. All objects, * including arrays, implement the methods of this class. * * @version 12/17/01 (CLDC 1.1) * @see java.lang.Class * @since JDK1.0, CLDC 1.0 */ public class Object { /** * Returns the runtime class of an object. That <tt>Class</tt> * object is the object that is locked by <tt>static synchronized</tt> * methods of the represented class. * * @return the object of type <code>Class</code> that represents the * runtime class of the object. */ // public final native Class getClass(); public final Class getClass() { throw new Error("getClass() NYI"); } /** * Returns a hash code value for the object. This method is * supported for the benefit of hashtables such as those provided by * <code>java.util.Hashtable</code>. * <p> * The general contract of <code>hashCode</code> is: * <ul> * <li>Whenever it is invoked on the same object more than once during * an execution of a Java application, the <tt>hashCode</tt> method * must consistently return the same integer, provided no information * used in <tt>equals</tt> comparisons on the object is modified. * This integer need not remain consistent from one execution of an * application to another execution of the same application. * <li>If two objects are equal according to the <tt>equals(Object)</tt> * method, then calling the <code>hashCode</code> method on each of * the two objects must produce the same integer result. * <li>It is <em>not</em> required that if two objects are unequal * according to the {@link java.lang.Object#equals(java.lang.Object)} * method, then calling the <tt>hashCode</tt> method on each of the * two objects must produce distinct integer results. However, the * programmer should be aware that producing distinct integer results * for unequal objects may improve the performance of hashtables. * </ul> * <p> * As much as is reasonably practical, the hashCode method defined by * class <tt>Object</tt> 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 * Java<font size="-2"><sup>TM</sup></font> programming language.) * * @return a hash code value for this object. * @see java.lang.Object#equals(java.lang.Object) * @see java.util.Hashtable */ // public native int hashCode(); public int hashCode() { return Native.toInt(this); } /** * Indicates whether some other object is "equal to" this one. * <p> * The <code>equals</code> method implements an equivalence relation: * <ul> * <li>It is <i>reflexive</i>: for any reference value <code>x</code>, * <code>x.equals(x)</code> should return <code>true</code>. * <li>It is <i>symmetric</i>: for any reference values <code>x</code> and * <code>y</code>, <code>x.equals(y)</code> should return * <code>true</code> if and only if <code>y.equals(x)</code> returns * <code>true</code>. * <li>It is <i>transitive</i>: for any reference values <code>x</code>, * <code>y</code>, and <code>z</code>, if <code>x.equals(y)</code> * returns <code>true</code> and <code>y.equals(z)</code> returns * <code>true</code>, then <code>x.equals(z)</code> should return * <code>true</code>. * <li>It is <i>consistent</i>: for any reference values <code>x</code> * and <code>y</code>, multiple invocations of <tt>x.equals(y)</tt> * consistently return <code>true</code> or consistently return * <code>false</code>, provided no information used in * <code>equals</code> comparisons on the object is modified. * <li>For any non-null reference value <code>x</code>, * <code>x.equals(null)</code> should return <code>false</code>. * </ul> * <p> * The <tt>equals</tt> method for class <code>Object</code> implements * the most discriminating possible equivalence relation on objects; * that is, for any reference values <code>x</code> and <code>y</code>, * this method returns <code>true</code> if and only if <code>x</code> and * <code>y</code> refer to the same object (<code>x==y</code> has the * value <code>true</code>). * * @param obj the reference object with which to compare. * @return <code>true</code> if this object is the same as the obj * argument; <code>false</code> otherwise. * @see java.lang.Boolean#hashCode() * @see java.util.Hashtable */ public boolean equals(Object obj) { return (this == obj); } /** * Returns a string representation of the object. In general, the * <code>toString</code> 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. * <p> * The <code>toString</code> method for class <code>Object</code> * returns a string consisting of the name of the class of which the * object is an instance, the at-sign character `<code>@</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: * <blockquote> * <pre> * getClass().getName() + '@' + Integer.toHexString(hashCode()) * </pre></blockquote> * * @return a string representation of the object. */ public String toString() { // return getClass().getName() + "@" + Integer.toHexString(hashCode()); return "This is just the object's hash code: "+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</code> methods. * <p> * 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. * <p> * 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: * <ul> * <li>By executing a synchronized instance method of that object. * <li>By executing the body of a <code>synchronized</code> statement * that synchronizes on the object. * <li>For objects of type <code>Class,</code> by executing a * synchronized static method of that class. * </ul> * <p> * 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(); public final void notify() { // nothing yet } /** * 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</code> methods. * <p> * 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. * <p> * This method should only be called by a thread that is the owner * of this object's monitor. See the <code>notify</code> 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(); public final void notifyAll() { // nothing yet } /** * Causes 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. * <p> * The current thread must own this object's monitor. * <p> * This method causes the current thread (call it <var>T</var>) to * place itself in the wait set for this object and then to relinquish * any and all synchronization claims on this object. Thread <var>T</var> * becomes disabled for thread scheduling purposes and lies dormant * until one of four things happens: * <ul> * <li>Some other thread invokes the <tt>notify</tt> method for this * object and thread <var>T</var> happens to be arbitrarily chosen as * the thread to be awakened. * <li>Some other thread invokes the <tt>notifyAll</tt> method for this * object. * <li>Some other thread {@link java.lang.Thread#interrupt() interrupts} * thread <var>T</var>. * <li>The specified amount of real time has elapsed, more or less. If * <tt>timeout</tt> is zero, however, then real time is not taken into * consideration and the thread simply waits until notified. * </ul><p> * The thread <var>T</var> 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 <tt>wait</tt> * method was invoked. Thread <var>T</var> then returns from the * invocation of the <tt>wait</tt> method. Thus, on return from the * <tt>wait</tt> method, the synchronization state of the object and of * thread <var>T</var> is exactly as it was when the <tt>wait</tt> method * was invoked. * <p> * If the current thread is * {@link java.lang.Thread#interrupt() interrupted} by another thread * while it is waiting, then an <tt>InterruptedException</tt> is thrown. * This exception is not thrown until the lock status of this object has * been restored as described above. * <p> * Note that the <tt>wait</tt> 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. * <p> * This method should only be called by a thread that is the owner * of this object's monitor. See the <code>notify</code> 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 another thread has interrupted * the current thread. The <i>interrupted status</i> 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; public final void wait(long timeout) throws InterruptedException { // nothing yet } /** * Causes 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. * <p> * This method is similar to the <code>wait</code> 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: * <blockquote> * <pre> * 1000000*timeout+nanos</pre></blockquote> * <p> * In all other respects, this method does the same thing as the * method {@link #wait(long)} of one argument. In particular, * <tt>wait(0, 0)</tt> means the same thing as <tt>wait(0)</tt>. * <p> * 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: * <ul> * <li>Another thread notifies threads waiting on this object's monitor * to wake up either through a call to the <code>notify</code> method * or the <code>notifyAll</code> method. * <li>The timeout period, specified by <code>timeout</code> * milliseconds plus <code>nanos</code> nanoseconds arguments, has * elapsed. * </ul> * <p> * The thread then waits until it can re-obtain ownership of the * monitor and resumes execution * <p> * This method should only be called by a thread that is the owner * of this object's monitor. See the <code>notify</code> 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 another thread has interrupted * the current thread. The <i>interrupted status</i> 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( /* #ifdef VERBOSE_EXCEPTIONS */ /// skipped "timeout value is negative" /* #endif */ ); } if (nanos < 0 || nanos > 999999) { throw new IllegalArgumentException( /* #ifdef VERBOSE_EXCEPTIONS */ /// skipped "nanosecond timeout value out of range" /* #endif */ ); } if (nanos >= 500000 || (nanos != 0 && timeout == 0)) { timeout++; } wait(timeout); } /** * Causes 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 word's this method behaves exactly as if it simply * performs the call <tt>wait(0)</tt>. * <p> * 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</code> method or the * <code>notifyAll</code> method. The thread then waits until it can * re-obtain ownership of the monitor and resumes execution. * <p> * This method should only be called by a thread that is the owner * of this object's monitor. See the <code>notify</code> 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 another thread has interrupted * the current thread. The <i>interrupted status</i> 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); } }