Here is the description of String.subString()


public String 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.


 "hamburger".substring(4, 8) returns "urge"
 "smiles".substring(1, 5) returns "mile"

beginIndex - the beginning index, inclusive.
endIndex - the ending index, exclusive.
the specified substring.
IndexOutOfBoundsException - 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.


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.

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?



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.


Craig Russell
Architect, Sun Java Enterprise System
408 276-5638
P.S. A good JDO? O, Gasp!