Patrick,

Thanks a lot for your posting. We were planning to do some
refactoring in the driver code, but currently nobody has enough time
for it. We will fix this inefficient code during refactoring.

Best regards,
Roman Rokytskyy

--- In Firebird-Java@y..., Pazzo Pazzo <pazzo1976@y...> wrote:
> Browsing the CVS sources I noticed the use of patterns
> which cause unnecessary object creations.
>
> 1. String and StringBuffer:
>
> Not optimal code:
>
> String sql = selectClause;
> sql += whereClause;
> sql += orderByClause;
> ...
>
> this generates the following code:
>
> String sql = selectClause;
> sql = new
> StringBuffer(sql).append(whereClause).toString();
> sql =
> StringBuffer(sql).append(orderByClause).toString();
> ...
>
> to avoid the unnecessary StringBuffer creation and
> enlargement (new char[] creation) a pattern like the
> following should be used:
>
> // The initial size of the internal char array should
> // be specified as needed or better be calculated a
> // priori, for example:
> // int len = selectClause.length() +
> whereClause.length() ...
> StringBuffer sb = new StringBuffer(100);
> sb.append(selectClause);
> sb.append(whereClause);
> sb.append(orderByClause);
> String sql = sb.toString();
>
>
>
> 2. Another place where object creations could be
> avoided are ArrayList creations.
>
> Not optimal code:
>
> ArrayList params = new ArrayList();
> if (<condition1>)
> params.add(<param1>);
> if (<condition2>)
> params.add(<param2>);
> ...
> foo(..., params, ...);
> ...
>
> Optimized code:
>
> ArrayList params = null;
> if (<condition1>) {
> if (params == null)
> params = new ArrayList();
> params.add(<param1>);
> }
> if (<condition2>) {
> if (params == null)
> params = new ArrayList();
> params.add(<param2>);
> }
> ...
> foo(..., params, ...);
> ...
>
> Of course all methods have to accept null parameters
> to avoid the need to create empty (dummy) objects.
>
>
>
> 3. Checking for empty strings:
>
> Not ideal code:
>
> if (!str.equals("")) {
> ...
> }
>
> Better:
>
> if (str != null && str.length() > 0) {
> ...
> }
>
>
> Java is a high level language and a lot of things are
> done behind the scenes. But considering these and
> others while coding can make even a Java app
> efficient.
>
> Best regards
> Patrick
>
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