Use the date class and the format class to format the current time of the system

One: Date------------String

Code 1: (Code two to optimize the displayed time format)

 PackageDatedemo;ImportJava.text.SimpleDateFormat;Importjava.util.Date;//Requirements: Print out the time of the current system//Required Classes: Date class: Generate Current system time//SimpleDateFormat class: Format the generated system time//Construction Method Summary SimpleDateFormat () Public classDatedemo { Public Static voidMain (string[] args) {//Create a dateDate d=NewDate (); //Create a subclassSimpleDateFormat str =NewSimpleDateFormat (); //using the method of the Str parent class, Format (date date) formats a date as a date/time string. //calling the parent class method formatString time=Str.format (d);    System.out.println (time); }}

Code two: An optimized output for the displayed time format

Package Datedemo;import java.text.simpledateformat;import java.util.date;//requirements: Print out the current system time//Required class: D Ate class: Generate current system time//SimpleDateFormat class: Format//construct method summary for generated system time SIMPLEDATEFO Rmat () public class Datedemo {public static void main (string[] args) {//Create a date d=new date ();//system.out.println (d);        /fri Sep 18:42:21 CST 2016//Create a subclass//simpledateformat str =new simpledateformat (); Using the method of the Str parent class, Format (date date) formats a date as a date/time string.              Call the parent class method format//string Time=str.format (d); System.out.println (time);//16-9-9 6:42//optimize: The format of the display is: September 9, 2016 18:42:21//yyyy MM month DD Day KK:MM:SS//custom method for parsing//method of String: SimpleDateFormat (string pattern) constructs a date format symbol for a given pattern and default locale Simpledateform        At        SimpleDateFormat str =new simpledateformat ("yyyy mm month DD Day KK:mm:ss");        String Time=str.format (d);        System.out.println (time); }}

Two  : String------------Date

 PackageDatedemo;Importjava.text.ParseException;ImportJava.text.SimpleDateFormat;Importjava.util.Date;//Requirements: Print out the time of the current system//Required Classes: Date class: Generate Current system time//SimpleDateFormat class: Format the generated system time//Construction Method Summary SimpleDateFormat ()//Date------String//////String----Date Public classDatedemo { Public Static voidMain (string[] args)throwsParseException {//Create a date//Date D=new date (); //System.out.println (d);//Fri Sep 18:42:21 CST//Create a subclass//SimpleDateFormat str =new simpledateformat (); //using the method of the Str parent class, Format (date date) formats a date as a date/time string. //calling the parent class method format//String Time=str.format (d); //System.out.println (time);//16-9-9 pm 6:42//optimize: Make time display format: September 9, 2016 18:42:21//yyyy mm month DD Day KK:MM:SS//custom methods for parsing strings//method: SimpleDateFormat (String pattern) constructs a simpledateformat with a given pattern and a date format symbol for the default locale. //SimpleDateFormat str =new simpledateformat ("yyyy mm month DD Day KK:mm:ss");//String Time=str.format (d);//System.out.println (time);//System.out.println ("------------------"); //String-------Date//format a string as a date format//Call Method: Date Parse (string source) parses the text from the beginning of the given string to generate a date. String str= "September 9, 2016 18:42:21"; Date DD=NewDate (); SimpleDateFormat d=NewSimpleDateFormat ("yyyy mm month DD Day KK:MM:SS"); DD=d.parse ("September 9, 2016 18:42:21");                    SYSTEM.OUT.PRINTLN (DD); }}

Use the date class and the format class to format the current time of the system