Anyone know why the MINUTE method in java.util.Caldendar returns an incorrect minute?
import java.util.Calendar;
public class Clock
{
// Instance fields
private Calendar time;
/**
* Constructor. Starts the clock at the current operating system time
*/
public Clock()
{
System.out.println(this.time.HOUR_OF_DAY+":"+this.time.MINUTE);
}
}
Calendar.MINUTE isn't the actual minute but rather a constant index value to pass into "get()" in order to get the value. For example:
System.out.println(this.time.get(Calendar.HOUR_OF_DAY) + ":" + this.time.get(Calendar.MINUTE));
HOUR_OF_DAY and MINUTE are public static fields that are meant to be passed into Calendar#get(int). Typically, you'd want to use Calendar.getInstance().get(Calendar.MINUTE) for the current minute. In your example though, you want time.get(Calendar.MINUTE).
import java.util.Calendar;
public class Clock { // Instance fields private Calendar time;
/**
* Constructor. Starts the clock at the current operating system time
*/
public Clock()
{
time = Calendar.getInstance();
System.out.println(this.time.get(Calendar.HOUR_OF_DAY) +
":" + this.time.get(Calendar.MINUTE));
}
}
----------------0--------------- ;)
ZonedDateTime.now( ZoneId.of( "America/Montreal" ) )
.getMinute()
34
( if current moment were 2016-01-23T12:34:56.789-05:00[America/Montreal] )
The other Answers are correct.
The modern way to do this work is with the java.time classes that supplant the troublesome old legacy date-time classes.
ZoneId z = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.now( z ); // zdt.toString(): 2016-01-23T12:34:56.789-05:00[America/Montreal]
int minute = zdt.getMinute(); // 34
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.
