Andreas Korneliussen wrote:
Lance J. Andersen wrote:
Here is the description of String.subString()
substring
public String
<http://java.sun.com/j2se/1.5.0/docs/api/java/lang/String.html>
*substring*(int beginIndex,
int endIndex)
Returns a new string that is a substring of this string. The
substring begins at the specified |beginIndex| and extends to the
character at index |endIndex - 1|. Thus the length of the substring
is |endIndex-beginIndex|.
Examples:
"hamburger".substring(4, 8) returns "urge"
"smiles".substring(1, 5) returns "mile"
*Parameters:*
|beginIndex| - the beginning index, inclusive.
|endIndex| - the ending index, exclusive. *Returns:*
the specified substring. *Throws:*
|IndexOutOfBoundsException
<http://java.sun.com/j2se/1.5.0/docs/api/java/lang/IndexOutOfBoundsException.html>|
- if the |beginIndex| is negative, or |endIndex| is larger than
the length of this |String| object, or |beginIndex| is larger
than |endIndex|.
So this indicates to me that a SQLException is what is to be expected
in this case in the case of Kathey's example.
I do not agree that a SQLException is expected.
Clob.getSubString(..) is 1 based, String.substring(..) is 0 based.
So Clob.getSubString(1, 0) maps down to String.substring(0, 0), which
returns the empty string. (And yes i do not like the fact that the
indexing is different then the JDK either for these methods...)
Yes but forget the getSubString(1,0) scenario getSubString(4,3) would
also apply to this case as well.
The issue as i said in my previous response to Thomas, is what does the
EG want to document at this time given the behavior has been undefined
since JDBC 2.0 and there are multiple JDBC drivers for some of the
backends that Thomas has listed and without explicitly testing all of
them, i certainly cannot speak to whether they all behave consistently.
If they do, great it is easier to address. If they do not, then it
boils down to whether they can agree on a behavior or it gets documented
as an implementation dependent issue.
"".substring(0,0) returns the empty string ("").
Andreas
Regards
Lance
Craig L Russell wrote:
Hi Lance,
Now that Kathey has kicked it back to you and me, how about updating
the to-be-released JDBC 4 to point out that a length of zero for the
getSubString is valid?
String getSubString(long pos,
int length)
throws SQLException
Retrieves a copy of the specified substring in the CLOB value
designated by this Clob object. The substring begins at position pos
and has up to length consecutive characters.
Parameters:
pos - the first character of the substring to be extracted. The
first character is at position 1.
length - the number of consecutive characters to be copied
We might simply add to this description.
length - the number of consecutive characters to be copied; 0 is a
valid value
We have a similar case with Blob byte[ ] getBytes().
Can you run this past the expert group for a quick consensus?
Thanks,
Craig
On Jul 14, 2006, at 11:13 PM, Kathey Marsden wrote:
Craig L Russell wrote:
You can always work around odd code on the other side of an
incompletely defined interface. But you probably have code on the
Derby side that also checks for the clob.length() == 0 and take
some extraordinary action.
So much easier for neither side to check for zero length and let
the natural boundary condition happen.
I am happy that you agree that the original DDLUtils code was
perfectly reasonable at not as Lance described it. I will exit
this issue now and allow you, Lance, or someone else with interest
determine the correct behavior, check it with Derby and file a
Derby bug if needed.
Kathey
Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!
