The BPEL 2.0 implementation within GlassFishESB offers a useful functoid that will generate a dateTime string that conforms to section 3.2.7 of the W3C Standard for the dateTime datatype. Unfortunately, there are no supporting functoids that facilitate arithmetic adjustment or alternative formatting of these strings.

A Java class is now available to help with this limitation. This may be invoked using the Sun BPEL to Java calling extension (See here for more information).

The class is com.sun.fast.util.DateAdjust

The methods are adjust(String,String,String) and format(String,String).

Adjusting the dateTime
Here's an example of how you can adjust a dateTime arithmetically in BPEL.

<assign name="AssignDateTime">
 <copy>
  <from>sxxf:current-dateTime()</from>
  <to variable="bpelDate"/>
 </copy>
</assign>
<assign name="AssignDoAdjustment">
 <copy xmlns:dateAdjust="java://com.sun.fast.util.DateAdjust">
  <from>dateAdjust:adjust($bpelDate,'M','11')</from>
  <to variable="bpelDate"/>
 </copy>
 </assign>

In the first assignment, we copy the dateTime string to a previously defined variable.

In the second assignment we invoke the adjust method and specify that we want 11 months added. The result is copied back to the same variable.

If the input dateTime to this method is 2009-03-17T09:17:03.01+00:00 then the output for this example would be 2010-02-17T09:17:03.01+00:00

[ Note:- This class does not offer any facility to adjust the fractional seconds part. This will always be returned as is ]

USAGE:

The first parameter must be a well-formed dateTime string.

The second parameter must be one of the following:-

Y - Year

M - Month

D - Day

H - hour

m - minute

S - second

The third parameter must be a string representation of an integer (may be negative)

Re-formatting the dateTime
This utility method uses java.text.SimpleDateFormat to perform the formatting. Therefore, the user needs to be aware of the format string syntax for this class.
Usage is very simple in the style shown earlier. In this assign extract, we want to return the date in yyMMdd style:-

  <from>dateAdjust:format($bpelDate,'yyMMdd')</from>

Using the same input as above, the output would be "090317"
The utility implementation is available here

The BPEL Editor in OpenESB and JavaCAPS 6 offers many utility functoids (Sun extensions to BPEL).

The DateTime functoid generates a string that conforms to the W3C standard (see section 3.2.7 here)

Whilst this generated string is entirely correct, it's worth noting that the Standard permits variations in structure. This can lead to difficulty when trying to process such data in Java.

I have constructed a utility class that will convert almost any valid W3C DateTime string to a java.util.Date object. [ W3C supports the notion of negative dates. My utility class does not support this because I can't think of a reasonable way to represent such a date using the java.util.Date class. Ideas welcome ] In addition, a further method is provided to convert from java.util.Date to a W3C DateTime that conforms precisely with the style implemented by the aforementioned functoid and which, by definition, conforms to the W3C specification.

Section 3.2.7.1 of the Standard defines in detail the lexical representation of a DateTime object. The main points of interest are that fractions of seconds are optional and, if present, have no maximum length (precision). Also, the timezone offset is optional and when present may take one of two forms. The simplest form is the letter Z (indicating Zulu time). Otherwise it is in the form of ('+'|'-')HH:MM being an offset from Zulu time. Z is equal to +00:00 which is equal to -00:00.

The BPEL functiod emits a string that always has two decimal fractions of seconds and uses the longer form for the timezone offset. This offset is always present.

The utility implementation is in the class com.sun.fast.util.W3CDateTime

Two static methods are of interest:-

java.util.Date toJavaDate(java.lang.String)

and

java.lang.String toW3CDate(java.util.Date)

Here are some examples of valid W3C DateTime strings that can be passed to the toJavaDate method:-

"2009-01-19T15:24:30"                      // Note the absence of either fractions of seconds or timezone data (Zulu is implied)
"2009-01-19T15:24:30.5"                   // No timezone
"2009-01-19T15:24:30Z"                   // Explicit Zulu timezone. No fractions
"2009-01-19T15:24:30.12-01:00"    // Fractions to 2 decimal places. Explicit timezone. This is the format generated by the toW3CDate method. The timezone data will be specific to your system's locale.

The utility implementation is available here