How To Snuff It Electrical Current Appointment As Well As Fourth Dimension Inwards Coffee Amongst Example

You tin acquire today's appointment or electrical flow appointment in addition to fourth dimension inwards Java yesteryear creating a new Date() object. Influenza A virus subtype H5N1 java.uti.Date object represents the electrical flow appointment in addition to fourth dimension instance inwards Java. Now, if you lot desire to appointment inwards DDMMYYYY format or whatever other appointment format, you lot tin easily convert the Date object to String yesteryear using SimpleDateFormat class. Since Date instance contains both appointment in addition to time, if you lot alone quest a appointment in addition to thence you lot tin farther convert the java.util.Date to java.sql.Date. Similarly, if you lot quest exactly fourth dimension in addition to thence you lot tin convert the java.util.Date to java.sql.Time, they stand upwardly for the appointment in addition to fourth dimension business office of java.util.Date object inwards Java. You tin besides purpose the java.util.Calendar degree to acquire the today's appointment in addition to time. Further, if you lot are using Java 8 in addition to thence you lot tin purpose new Date in addition to Time API classes similar LocalDate, LocalTime, in addition to LocalDateTime to acquire the electrical flow date, time, in addition to date-time inwards Java.


Java ever had issues amongst Date, Time, in addition to Timezone. There initial ii attempts inwards price of one-time appointment in addition to fourth dimension API from JDK 1 in addition to Calendar API from JDK 1.4 was plagued amongst thread-safety in addition to usability issues. Thankfully, they bring got it correct tertiary fourth dimension amongst novel Date in addition to Time API of Java 8. I strongly advise every Java developer acquire Java 8, peculiarly novel Date in addition to Time API. Don't exactly acquire busy amongst lambdas in addition to stream. Unfortunately, not all Java 8 books comprehend this of import theme thence makes certain you lot read Java SE 8 for Impatient yesteryear Cay S. Horstmann to acquire this of import development.

Java Program to acquire electrical flow appointment in addition to time

Here is our sample Java plan to impress the electrical flow appointment in addition to fourth dimension inwards Java.  In this program, I bring demonstrated that java.util.Date instance represents both appointment in addition to time, in addition to if you lot desire to extract appointment part, you lot tin but convert the util appointment to java.sql.Date inwards Java.



Similarly, you lot tin extract the fourth dimension business office from the java.util.Date you lot tin convert it to java.sql.Time class. An interesting matter to know is that both java.sql.Date in addition to java.sql.Time are subclasses of java.util.Date, but they don't follow Liskov Substitution principle. You cannot run yesteryear java.sql.Date or java.sql.time, where a java.util.date instance is needed.

Since Date is nada but number of millisecond from epoch (1st Jan 1970, midnight GMT), it doesn't check timezone information, but when you lot impress date, it's toString() method is called which is overridden to impress the appointment inwards the local timezone. You tin convert Date to String yesteryear using SimpleDateFormat every bit good e.g. a appointment inwards DDMMYYY format.

package hello;  import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.Date;   public class JavaDatePrimer{  public static void main(String[] args) {  // electrical flow appointment in addition to fourth dimension inwards Java Date today = new Date(); System.out.println("current appointment in addition to time: " + today);  // displaying alone electrical flow appointment inwards Java Date currentDate = new java.sql.Date(today.getTime()); System.out.println("current date: " + currentDate);  // displaying alone electrical flow fourth dimension inwards Java Date currentTime = new java.sql.Time(today.getTime()); System.out.println("current time: " + currentTime);   // today's appointment inwards ddMMyyyy inwards Java DateFormat df = new SimpleDateFormat("ddMMyyyy"); String todayDate = df.format(today); System.out.println("Today's appointment inwards ddMMyyyy format: " + todayDate);  // today's appointment inwards mm/dd/yyyy format df = new SimpleDateFormat("MM/dd/yyyy"); todayDate = df.format(today); System.out.println("Today's appointment inwards MM/dd/yyyy format: " + todayDate); } }  Output electrical flow appointment and time: Monday February 15 18:21:44 SGT 2016 electrical flow date: 2016-02-15 electrical flow time: 18:21:44 Today's appointment inwards ddMMyyyy format: 15022016 Today's appointment in MM/dd/yyyy format: 02/15/2016

Important points to Remember  about Date in addition to Time inwards Java

1. Use M for month, modest instance m is for minute
2. Use y for Year, uppercase instance Y is invalid
3. Be careful acre using SimpleDateFormat, it is non thread-safe in addition to should non live on shared amid multiple threads.
4. The java.util.Date instance doesn't keep timezone, but when you lot impress the appointment object, it's toString() impress the appointment inwards your local timezone.
5. Prefer novel Date in addition to Time API from Java 8 if you lot are lucky to live on running inwards JDK 8. 

That's all virtually how to acquire the electrical flow appointment in addition to fourth dimension inwards Java. You tin besides purpose the java.util.Calendar degree to acquire the electrical flow appointment in addition to fourth dimension inwards Java every bit well. For farther reading on appointment in addition to time, you lot tin read Core Java for Impatient, i of the best books to acquire heart in addition to person Java.

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