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how to get dateTime based on hour and minute

I have hour and minute in edittext.(say for example 10:50)
how to get today's DateTime(like yyyy-MM-dd HH:mm:ss) based on above edit text value 10:50
UPDATE:
this worked for me:
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR, selectedHour);
calendar.set(Calendar.MINUTE, selectedMinute);
thank you all

EDIT: take a look at this other stackoverflow post about why one should prefer using the Java 8 java.time classes over Calendar or Date
In your instance, in order to parse an input in the form "HH:mm", you can create a DateTimeFormatter and use the static method LocalTime.parse(inputString, dateTimeFormatter) to get a LocalTime object
For example:
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm");
LocalTime time = LocalTime.parse(timeInputString, formatter);
Take a look at the Java documentation for DateTimeFormatter for more information on the patterns for years, days, or whatever.
If you're wanting to get both the date and time from a string such as "10:50", you won't be able to using the LocalDateTime.parse method because it can't obtain the date from an "HH:mm" string. So the way around this is to create the time off of LocalTime.parse as shown above, and then get the current date using the static method LocalDate.now(); And then combine those two results into a LocalDateTime object using it's static factory method LocalDateTime.of(date, time)
For example:
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm");
LocalTime time = LocalTime.parse(timeInputString, formatter);
LocalDate date = LocalDate.now();
LocalDateTime dateTime = LocalDateTime.of(date, time);

Calendar cal = new Calendar.getInstance();// today's date
cal.set(Calendar.HOUR, 10);
cal.set(Calendar.MINUTE, 50);
cal.set(Calendar.SECOND, 0);
System.out.println(cal.getTime()); //see the result
now , it's up to you to put them directly in cal.set with variables (not manually writing 10 ,50 , it's up to your creativity )
And this answer is with Calendar because you tagged Calendar in your question , you can also use something else than Calender

you just need use this function.
// hourMintText = "hh:mm"
private String getTodayAsFormat(String hourMintText){
String[] hourMinAsArray = hourMintText.split(":");
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, Integer.parseInt(hourMinAsArray[0]));
calendar.set(Calendar.MINUTE, Integer.parseInt(hourMinAsArray[1]));
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-mm-dd hh:mm", Locale.ENGLISH);
return simpleDateFormat.format(calendar.getTimeInMillis());
}

Try this:
String dateTime = new SimpleDateFormat("dd-MM-yyyy hh-mm-ss aa", Locale.getDefault())
.format(new Date());

How set the time to zero in given format yyyy-MM-dd HH:mm:ss(Java)

I am given an input date string for ex:2015-06-02 12:60:30 and the output should be 2015-06-02 00:00:00 i.e how to set the HH:mm:ss to zero in the given format yyyy-MM-dd HH:mm:ss ?

use yyyy-MM-dd 00:00:00 format instead of yyyy-MM-dd HH:mm:ss
it will change the hours, minutes and seconds to zero instead of actual values
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd 00:00:00");
String dateValue = dateFormat.format(new Date());
System.out.println(dateValue);

You can try to use this:
calendar.set(Calendar.HOUR_OF_DAY, 0);
Something like this:
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Calendar c = Calendar.getInstance();
c.set(Calendar.HOUR, 0);
c.set(Calendar.MINUTE, 0);
c.set(Calendar.SECOND, 0);
System.out.println(sdf.format(c.getTime()));
c.set(Calendar.HOUR_OF_DAY, 0);
System.out.println(sdf.format(c.getTime()));

Simply provide a format for the portion of the "date" you want to keep, for example...
String text = "2015-06-02 12:60:30";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date date = sdf.parse(text);
SimpleDateFormat out = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
System.out.println(out.format(date));
Outputs...
2015-06-02 00:00:00
This is a little trick, which is actually described in the JavaDocs
Parses text from the beginning of the given string to produce a date. The method may not use the entire text of the given string.
Emphasis added by me

try this
SimpleDateFormat sm = new SimpleDateFormat("yyyy-MM-dd");
String strDate = sm.format(myDate);

If you don't require validation of the input format, you could use a regular expression:
input.replaceAll("\d\d:\d\d:\d\d", "00:00:00")
However, note that this conversion is not necessarily one which yields a valid time: midnight might not be valid, depending upon the date you are converting and its time zone, so this might not yield a valid time. (The start of daylight savings time in Asia/Gaza is the oft-cited example).

Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR,2015);
cal.set(Calendar.MONTH,6);
cal.set(Calendar.HOUR_OF_DAY,2);
cal.set(Calendar.MINUTE,0);
cal.set(Calendar.SECOND,0);
cal.set(Calendar.MILLISECOND,0);
Date d = cal.getTime();
And to format it you can use:
SimpleDateFormat sdFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String formatted = sdFormat.format(cal.getTime());

How to convert String timestamp to milliseconds

I am running one query on oracle sql which returns me timestamp part of of sysdate in string
something like "16:30:0.0"
so i want to know how to convert it to milliseconds.
please help?

This is using the standard Java Date API.
DateFormat df = new SimpleDateFormat("HH:mm:ss.SSS");
df.setTimeZone(TimeZone.getTimeZone("UTC"));
df.parse("16:06:43.233").getTime();
If you're using Java 8, see the new java.time API. If not, and you're going to do a lot of date-time-related work, see JodaTime

Use ResultSet's getTime(column)-method instead of getString(column) to avoid having to do the conversion yourself: http://docs.oracle.com/javase/7/docs/api/java/sql/ResultSet.html#getTime%28int%29

Try this,
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss.SSS");
Date date = sdf.parse("16:30:0.0");
System.out.println(date.getTime());
But, this code will return milliseconds since 01.01.1970 16:30:00.000. If you want to get millis from the current day you can do the following.
Calendar today = Calendar.getInstance();
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.set(Calendar.YEAR, today.get(Calendar.YEAR));
cal.set(Calendar.MONTH, today.get(Calendar.MONTH));
cal.set(Calendar.DAY_OF_MONTH, today.get(Calendar.DAY_OF_MONTH));
System.out.println(cal.getTimeInMillis());

Current Date in Java 1.4

For getting Current date in mm/dd/yyyy format I am using the below code
SimpleDateFormat sdf = new SimpleDateFormat("mm/dd/yyyy");
Date date = new Date();
String date3= sdf.format(date);
date = sdf.parse(date3);
but everytime I print the date ,it gives me wrong and random output
output
Currentd Date:: 49/22/2013
output
Currentd Date:: 07/22/2013
Kindly suggest as what I should use to get current date.
The Java Version I am using is 1.4

Change "mm/dd/yyyy" into "MM/dd/yyyy". m(lowercase) is use for minutes not for month. For month you should use M(uppercase)

You might want to use MM instead of mm in the format pattern which will give you month instead of minutes.

Use MM/dd/yyyy
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy");
MM - Month
mm - Minute

m = Minute
M = Month
Thus you have to use "MM/dd/yyyy"

Try
Date date = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm");
System.out.println(sdf.format(date));

Try
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
System.out.println(dateFormat.format(cal.getTime())); //2014/08/06 16:00:22OR
Calendar cal = Calendar.getInstance();
System.out.println(cal.getTime()); //2014/08/06 16:00:22

How to get DAY of the WEEK from the datetime format in JAVA?

I have date time information in this format:
String reportDate="2012-04-19 12:32:24";
I want to have as output day of the week (Thursday or 4 as result anyway is good).
How to achieve this?
Thanks

Use the Calendar after parsing the string:
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:SS");
Date d = sdf.parse(reportDate);
Calendar cal = Calendar.getInstance();
cal.setTime(d);
return cal.get(Calendar.DAY_OF_WEEK);

Use the SimpleDateFormat to parse the String then you have a Date object an can get the day of the week.

Parse your date to an actual Date Object and then pass it to a Calendar Instance (through setTime(Date date)). You can then use the DAY_OF_WEEK to get a number representing the days of the week.

Try,
System.out.println(new SimpleDateFormat("E").format(new SimpleDateFormat("yyyy-MM-dd").parse(reportDate)));
System.out.println(new SimpleDateFormat("F").format(new SimpleDateFormat("yyyy-MM-dd").parse(reportDate)));