java常用类（Java common classes）.docVIP

java常用类（Java common classes） Class libraries commonly used in Java: Class Object: the parent class of all classes Methods: (equals) for determining whether an object is equal to another object in the Object class, this method will determine whether the two objects have the same reference, if they are equal or not equal. Finalize () This method is called by the garbage collector of the object when the garbage collector determines that there is no more reference to the object. Notify () Wakes up a single thread waiting on this object monitor. NotifyAll () Wake up all threads waiting on this object monitor Void, wait () Causes the current thread to wait before the other thread calls the notify () method or notifyAll () method of this object. Void wait (long timeout) Causes the current thread to wait before the other thread calls the notify () method or notifyAll () method of the object, or exceeds the specified amount of time. Void wait (long, timeout, int, nanos) The current thread waits until the other thread calls the notify () method or notifyAll () method of the object, or some other thread interrupts the current thread, or has exceeded a certain amount of actual time. Math and Random classes Calendar and SimpleDateFormat classes StringBuffer and Runtime classes (get JVM spatial information) Locale and ResouceBundle classes System Date NumberFormat Format (NumberFormat, DateFormat, MessageFormat) Arrays class Class Comparable and Comparator comparators Observable class observer design patterns Regular expression: Class: Java.lang.String Java.util.regex.Pattern Java.util.regex.Matcher Pattern, Matcher class character X characters x The backslash character \ \ \0n n with the octal value character 0 (0 n = 7) \0nn with the octal value of 0 characters NN (0 n = 7) \0mnn with the octal value of 0 characters MNN (0 = 3, m = 0 n = 7) \xhh with sixteen decimal value 0x characters HH \uhhhh with sixteen decimal value 0x characters hhhh \t tab (\u0009) \n new line (