陕西seoapp优化

Object类

Object类是Java中所有类的父类，没有Object类Java面向对象无从谈起。作为其他所有类的基类，Object具有哪些属性和行为，是Java语言设计背后的思维体现。

Object类位于java.lang包中，java.lang包包含着Java最基础和核心的类，在编译时会自动导入。Object类没有定义属性，一共有13个方法，具体的类定义结构如下图：

Object的作者unascribed，未知，不过贡献是有目共睹的

//说明：源码中的注释已进行删减
package java.lang;/*** 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.** @author  unascribed* @see     java.lang.Class* @since   JDK1.0*/
public class Object {private static native void registerNatives();static {registerNatives();}public final native Class<?> getClass();/**** @return  a hash code value for this object.* @see     java.lang.Object#equals(java.lang.Object)* @see     java.lang.System#identityHashCode*/public native int hashCode();/**** @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);}/**** @return     a clone of this instance.* @throws  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 native Object clone() throws CloneNotSupportedException;/**** @return  a string representation of the object.*/public String toString() {return getClass().getName() + "@" + Integer.toHexString(hashCode());}/*** Only one thread at a time can own an object's monitor.** @throws  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();/**** @throws  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();/*** @param      timeout   the maximum time to wait in milliseconds.* @throws  IllegalArgumentException      if the value of timeout is*               negative.* @throws  IllegalMonitorStateException  if the current thread is not*               the owner of the object's monitor.* @throws  InterruptedException if any thread interrupted the*             current thread before or while the current thread*             was waiting for a notification.  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;/**** @param      timeout   the maximum time to wait in milliseconds.* @param      nanos      additional time, in nanoseconds range*                       0-999999.* @throws  IllegalArgumentException      if the value of timeout is*                      negative or the value of nanos is*                      not in the range 0-999999.* @throws  IllegalMonitorStateException  if the current thread is not*               the owner of this object's monitor.* @throws  InterruptedException if any thread interrupted the*             current thread before or while the current thread*             was waiting for a notification.  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("timeout value is negative");}if (nanos < 0 || nanos > 999999) {throw new IllegalArgumentException("nanosecond timeout value out of range");}if (nanos > 0) {timeout++;}wait(timeout);}/**** @throws  IllegalMonitorStateException  if the current thread is not*               the owner of the object's monitor.* @throws  InterruptedException if any thread interrupted the*             current thread before or while the current thread*             was waiting for a notification.  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);}/*** @throws Throwable the {@code Exception} raised by this method* @see java.lang.ref.WeakReference* @see java.lang.ref.PhantomReference* @jls 12.6 Finalization of Class Instances*/protected void finalize() throws Throwable { }
}

根据源码的相关注释，已经可以有一定的了解。具体不多赘述，当然有一篇详细的文章可以参考：

Java总结篇系列：java.lang.Object