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SimpleDateFormat parsing date string incorrectly

I'm trying to parse a String into a Date and then format that Date into a different String format for outputting.
My date formatting code is as follows:
SimpleDateFormat dateFormatter = new SimpleDateFormat("dd/MM/yyyy");
SimpleDateFormat dateParser = new SimpleDateFormat("d/M/yyyy h:m:s a");
String formattedDocumentDate = dateFormatter.format(dateParser.parse(sysObj.getString("document_date")));
The result of sysObj.getString("document_date") is 1/31/2013 12:00:01 AM. And when I check the value of formattedDocumentDate I get 01/07/2015.
Any help is much appreciated.

You are parsing days 31 as months. SimpleDateFormat tries to give you a valid date. Therefore It adds to 1/0/2013 31 months. This is 2 years and 7 month. So you get your result 01/07/2015. So SimpleDateFormat works correct.
One solution for you is to change your date pattern to M/d/yyyy h:m:s a or your input data.
To avoid these tries you have to switch off SimpleDateFormat lenient mode. Then you will get an exception if the format does not fit.

It looks like your input format is actually months first, then days. So should be "MM/dd/yyyy".
So:
SimpleDateFormat dateFormatter = new SimpleDateFormat("dd/M/yyyy");
SimpleDateFormat dateParser = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss a");
String formattedDocumentDate = dateFormatter.format(dateParser.parse(sysObj.getString("document_date")));

Another example like this
SimpleDateFormat sdfInput = new SimpleDateFormat("yyyyMMdd");
System.out.println("date is:"+new java.sql.Date( sdfInput.parse("20164129").getTime() ));
Output is: 2019-05-29
I expect to throw parse exception but not (41)is not a valid month value.
on the other hand if I gave 20170229, system can recognize the February of 2017 doesn't have a lap year and return 2017-03-01 interesting.

Getting formatted date in date format rather than String

I'm running the program written below, but instead of printing in mm/dd/yyyy hh:mm format it prints in the normal date format(ie. Day Date and time)
SimpleDateFormat sdf = new SimpleDateFormat("mm/dd/yyyy hh:mm");
Date date = sdf.parse(sdf.format(Calendar.getInstance().getTime()));
The reason i'm doing this is because the existing method accepts parameters in Date format, so i need to send the above mentioned date object to it.
Please point out the mistake or suggest some other alternative.
Thanks

Date objects don't have a format. The Date class is a wrapper around a single long, the number of milliseconds since the epoch. You can't "format" a Date, only a String. Pass around a Date/Calendar internally, and format it whenever you need to display it, log it, or otherwise return it to the user.

Change the format to MM/dd/yyyy. Month is denoted by capital M.
Check below URL for valid formats
http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html

Your formatter works quite fine (apart from the mm vs. MM bug). You get a formatted string from the date and then create a copy from your date by parsing the formatted string:
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy hh:mm");
Date now = Calendar.getInstance().getTime();
String formattedNow = sdf.format(now); // == "09/24/2013 01:59"
Date now2 = sdf.parse(formattedNow); // == now

How to display the date format in android?

String date="21-04-2013";
In my android application
Here i want to display the date in the following format like "21" is a separate string and month is like "Apr" as a separate string and year is like "13"as a separate string without using String functions.Can anybody plz give some suggestions to convert in this format?any date function is available?

You'll want to take a look at the SimpleDateFormat class for parsing the date string. In order to end up separate strings without using string functions, you'll probably need multiple formatters for the output too. It would look somewhat like this:
String date = "21-04-2013";
SimpleDateFormat dateFormatter = new SimpleDateFormat("dd-MM-yyyy"); // input date
Date outDate = dateFormatter.parse(date);
SimpleDateFormat dayFormatter = new SimpleDateFormat("dd"); // output day
SimpleDateFormat monthFormatter = new SimpleDateFormat("MMM"); // output month
SimpleDateFormat yearFormatter = new SimpleDateFormat("yy"); // output year
String day = dayFormatter.format(outDate);
String monthy = monthFormatter.format(outDate);
String year = yearFormatter.format(outDate);
If you were to use String.split(), you could get rid of at least two of the formatters in above snippet.

This is the class you'll need: DateFormat
Examples are provided in the link, but in short, you'll first need to parse the date, and then format the date again.

Android change the format of a string representing time and date

I have the string in the format ss:mm:hh dd/mm/yyyy as for example 58:21:16 20/07/2012 but i want the string to be in the format as dd/mmm/yyyy hh:mm:ss as for example 19/Mar/2012 17:34:58.
But i am getting format as 20:040:2012 02:40:53.
Here the string i am passing is static.
Anybody having any sort of idea regarding this can help.Any sort of help is appreciated.

Use a capital M for month.
SimpleDateFormat sdf = new SimpleDateFormat("dd/MMM/yyyy hh:mm:ss");
textView.setText(sdf.format(new Date()));
M stands for month and m for minute.
Reference

java Date and time format

how to format "2011-10-25T13:00:00Z" string into date and time
i used simple date format class
SimpleDateFormat sim=new SimpleDateFormat("yyyy-MM-dd");
but it only giving the date value. not time values
please help me to solve this problem

Use the format "yyyy-MM-dd'T'HH:mm:ss'Z'" for parsing this date format. See the documentation of SimpleDateFormat for more info. Code will look like this
String dateStr = "2011-09-19T15:57:11Z";
String pattern = "yyyy-MM-dd'T'HH:mm:ss'Z'";
Date date = new SimpleDateFormat(pattern).parse(dateStr);

This is because "yyyy-MM-dd" only mentions year (yyyy), month (MM) and date (dd). Try adding hh:mm if you want hours and minutes.
Example:
SimpleDateFormat sim = new SimpleDateFormat("yyyy-MM-dd hh:mm");
System.out.println(sim.format(new Date())); // prints "2011-10-27 01:56"
The full documentation of the format-string and its parts is found here. The documentation includes this example:
"yyyy-MM-dd'T'HH:mm:ss.SSSZ" - 2001-07-04T12:08:56.235-0700
Perhaps it's something like that you're looking for.