CODEWITHSUNDEEP
javadatedate-format
rematnarab
rematnarab

Reputation: 1325

Date localization in java using DateFormat.getDateInstance

I have a date which must be localized. Below code returns 5/1/12 19:06:34 but the result i want is 05/01/12 19:06:34 Could you please tell me how to manage this. 

  private String localizeDate(String date){ //Format is 2012-05-01 19:30:49

    Locale loc = DataContextHolder.getDataContext().getLocale();
    SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", loc);

    Date parsed=null;
    try {
        parsed = formatter.parse(date);
    } catch (ParseException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    DateFormat df = DateFormat.getDateInstance(DateFormat.SHORT, loc);

    String localizedDate = df.format(parsed) + " " + date.substring(11, 13) + ":"
            + date.substring(14, 16) + ":"
            + date.substring(17, 19);

    return localizedDate;
}

Upvotes: 1

Views: 5259

Answers (3)

Basil Bourque
Basil Bourque

Reputation: 338181

Problems

You have multiple problems happening with your code.

Time-Zone

One problem is that you are localizing without handling time zone. The parsing will apply the JVM's default time zone. That means running on different computers with different time zone settings yields different results. Generally best to specify a time zone rather than rely on default.

Formatting, Not Localizing

Another problem is that if you are truly localizing, you would not be specifying the details of the format. You would let the locale drive the formatting, whatever is appropriate to that locale and to the user's own localization settings.

Avoid java.util.Date

Yet another problem is that you are using the java.util.Date class bundled with Java. That class, and its sibling java.util.Calendar, are notoriously troublesome. Avoid them. Use either the Joda-Time framework or the new java.time.* package in Java 8.

ISO 8601

Your input string is very close to the standard ISO 8601 format, like this: 2014-02-07T07:06:41+03:00. Your text is merely missing a T in the middle and a time zone offset.

The Joda-Time framework uses ISO 8601 by default. So replacing that space with a "T" lets you pass the string directly to a DateTime constructor. No need for a formatter and parsing, as the DateTime constructor will do that work for you automatically.

Note that including or omitting the time zone offset from the end of the string input changes the behavior of constructing a DateTime. Without an offset, the string is parsed as if it occurred at the specified time within the passed time zone (the 2nd argument, see code example below). On the other hand, if you do include an offset in your input, the string is parsed as if it occurred at the specified time in the offset's locality, and then adjusts the time to the passed time zone argument.

Joda-Time Example

Here is some example code in Joda-Time 2.3.

DateTimeZone timeZone = DateTimeZone.forID( "Europe/Istanbul" );

String inputOriginal = "2012-05-01 19:30:49";
String input = inputOriginal.replace( " ", "T" );

DateTime dateTime = new DateTime( input, timeZone );
// Or if your input is UTC/GMT (no time zone offset), pass a predefined DateTimeZone constant.
//DateTime dateTime = new DateTime( input, DateTimeZone.UTC );

We have our date-time value in hand. Now we proceed to generate formatted strings from that date-time. We do so by using Joda-Time’s Locale-sensitive formatting facility. Note that not only the format is localized, so is the text of the month and day names localized to appropriate language.

// Create a formatter from a two-character style pattern.
// The first character is the date style, and the second character is the time style. 
// Specify a character of 'S' for short style, 'M' for medium, 'L' for long, and 'F' for full. 
// A date or time may be ommitted by specifying a style character '-'. 
java.util.Locale locale = new java.util.Locale( "tr", "TR" ); // Turkey chosen as an example.
String output_ShortShort = DateTimeFormat.forStyle( "SS" ).withLocale( locale ).print( dateTime );
String output_LongShort = DateTimeFormat.forStyle( "LS" ).withLocale( locale ).print( dateTime );

Dump to console…

System.out.println( "input: " + input );
System.out.println( "dateTime: " + dateTime );
System.out.println( "dateTime in UTC/GMT: " + dateTime.toDateTime( DateTimeZone.UTC ) );
System.out.println( "output_ShortShort: " + output_ShortShort );
System.out.println( "output_LongShort: " + output_LongShort );

When run…

input: 2012-05-01T19:30:49
dateTime: 2012-05-01T19:30:49.000+03:00
dateTime in UTC/GMT: 2012-05-01T16:30:49.000Z
output_ShortShort: 01.05.2012 19:30
output_LongShort: 01 Mayıs 2012 Salı 19:30

Upvotes: 2

cheeken
cheeken

Reputation: 34655

You can avoid leading zeros by reducing the number of consecutive pattern letters for that particular element. Multiple pattern letters in a row tell the date formatter that, at minimum, you want that many characters to express that value.

In your example, the following should resolve your problem.

new SimpleDateFormat("y-M-d H:m:s", loc);

Find more in the SimpleDateFormat documentation.

For clarity, see the following example.

SimpleDateFormat a = new SimpleDateFormat("yyyyy-MMMM-dddd HHH:mmmm:sssss");
SimpleDateFormat b = new SimpleDateFormat("y-M-d H:m:s");

System.out.println(a.format(new Date())); 
// Prints 02012-June-0005 012:0027:00026
System.out.println(b.format(new Date()));
// Prints 12-6-5 12:27:26

Upvotes: 3

g13n
g13n

Reputation: 3246

You need to choose the appropriate date formatter. Please read the documentation here:

http://docs.oracle.com/javase/6/docs/api/java/text/SimpleDateFormat.html

Upvotes: 0

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