.net JSON Date Format

Question

As a response from the .net service, I get this date format: / Date (1233323754523 + 0100) /

1233323754523 is a date in timestamp format, but I don’t know what +0100 means and how to generate this from java code?

thanks

Answer 1

I assume the timestamp is in UTC, and the offset is the UTC offset of the desired local time. If the timestamp is at a given offset from UTC, you will have to generate it a little differently.

A reliable way to generate this in Java would be to use the Joda-Time library, which is much better than the default java.util.Date and java.util.Calendar .

 // A formatter that prints the timezone offset DateTimeFormatter fmt = DateTimeFormat.forPattern("Z"); // The current date+time in the system default timezone. DateTime dt = new DateTime(); // Create the result. String result = "/Date(" + dt.getMillis() + fmt.print(dt) + ")/"; 

It is a little annoying that DateTimeFormat not able to output milliseconds from an era; this is what dt.getMillis() concatenation requires.

To generate the same using java.util classes would look something like this:

 // A formatter that prints the timezone offset SimpleDateFormat df = new SimpleDateFormat("Z"); // Current date+time in system default timezone. Calendar now = Calendar.getInstance(); // Don't forget this if you use a timezone other than system default: df.setTimeZone( now.getTimeZone() ); // Create the result String result = "/Date(" now.getTimeInMillis() + df.format(now.getTime()) +")/"; 

This is essentially the same as the Joda-Time example, but the bit in which you need to copy the time zone from the calendar to the date format is the main source of errors.

Answer 2

The second number simply indicates that the DateTime value should be interpreted as local time (instead of UTC), the number itself is ignored. This is described in the additional information / date format section of the document format at http://msdn.microsoft.com/en-us/library/bb412170.aspx .

Answer 3

The question is a bit outdated, but I think there are still people banging their heads against the wall because of this excellent choice of date format;)

An adapter of type Serialization and deserialisation of a DateTime date value in .NET Json format in Java for Gson This worked for me now, starting from about two years old.

 package x import java.lang.reflect.Type; import java.text.DecimalFormat; import java.util.Date; import java.util.TimeZone; import java.util.regex.Pattern; import com.google.gson.JsonDeserializationContext; import com.google.gson.JsonDeserializer; import com.google.gson.JsonElement; import com.google.gson.JsonParseException; import com.google.gson.JsonPrimitive; import com.google.gson.JsonSerializationContext; import com.google.gson.JsonSerializer; /** * Serialises and deserialises a string representing a date produced by a .NET web service. * * @author Diego Frehner */ public class TypeAdapterDate implements JsonSerializer<Date>, JsonDeserializer<Date> { /** Pattern for parsing date time values sent by a .NET web service. */ private static Pattern pattern = Pattern.compile("^/Date\\([0-9\\+-]*\\)/$"); private static DecimalFormat formatter = new DecimalFormat("#00.###"); private static final long HOUR_IN_MILLISECOND = 60L * 60 * 1000; private static final String minusSign = "-"; private static final String plusSign = "+"; @Override public Date deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException { String value = json.getAsString(); // example .NET web service return value: /Date(1302847200000+0200)/ // milliseconds since midnight 1970 UTC + time zone offset of the server to UTC // GMT == UTC == UT it all the same...afaik if (!pattern.matcher(value).matches()) { return null; } // get UTC millisecond value long utcMillisecond = Long.parseLong(value.substring(value.indexOf("(") + 1, value.indexOf(")") - 5)); // new Date(long) takes milliseconds since 1970 in UTC return new Date(utcMillisecond); } @Override public JsonElement serialize(Date arg0, Type arg1, JsonSerializationContext arg2) { Date date = (Date) arg0; int zoneOffsetMillisecond = TimeZone.getDefault().getOffset(date.getTime()); String sign = plusSign; if (zoneOffsetMillisecond < 0) { // negative offset sign = minusSign; zoneOffsetMillisecond *= -1; } int minute = (int) (zoneOffsetMillisecond % HOUR_IN_MILLISECOND); int hour = (zoneOffsetMillisecond / 1000 / 60 / 60); return new JsonPrimitive("/Date(" + date.getTime() + sign + formatter.format(hour) + formatter.format(minute) + ")/"); } }