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https://issues.apache.org/jira/browse/DBUTILS-48?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12670809#action_12670809
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dfabulich edited comment on DBUTILS-48 at 2/5/09 8:30 AM:
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Here's a patch to update DbUtils for 1.5. It's backwards-compatible with the
old API; in fact, most of my changes are type-erased at compile time.
The biggest change was to change the order of the QueryRunner.query method
signatures (var-args have to go at the end). The old functions are left in,
but deprecated.
I also added a helper static method ResultSetIterator.iterable, which returns
an Iterable, for use in for-each loops. You'd use it like this:
{code}
for (Object[] row : ResultSetIterator.iterable(resultSet)) {
// do stuff
}
{code}
was (Author: dfabulich):
Here's a patch to update DbUtils for 1.5. It's backwards-compatible with
the old API; in fact, most of my changes are type-erased at compile time.
The biggest change was to change the order of the QueryRunner.query method
signatures (var-args have to go at the end). The old functions are left in,
but deprecated.
I also added a helper static method ResultSetIterator.iterable, which returns
an Iterable, for use in for-each loops. You'd use it like this:
for (Object[] row : ResultSetIterator.iterable(resultSet) {
// do stuff
}
> Maintaining a parallel Java 1.5 version of DButils
> --------------------------------------------------
>
> Key: DBUTILS-48
> URL: https://issues.apache.org/jira/browse/DBUTILS-48
> Project: Commons DbUtils
> Issue Type: New Feature
> Reporter: Olivier Grégoire
> Priority: Minor
> Fix For: 1.2
>
> Attachments: generics.patch
>
>
> Well, DButils was a great step forward when managing a database. But Java 5
> came and added a lot of new features to the language, including generics,
> which I think is easy to put in place.
> The base change of all this is changing the signature of ResultSetHandler:
> public interface ResultSetHandler<T> {
> public T handle(ResultSet rs) throws SQLException;
> }
> With this code, we can easily provide directly from the QueryRunner a
> specific object without having to cast it.
> Furthermore, we can also make the queries much more efficient, and declare
> only 2 method instead of three as it is currently the case:
> public <T> T query(String sql, ResultSetHandler<T> handler, Object...
> params) throws SQLException {
> Connection connection = this.prepareConnection();
> try {
> return this.query(connection, sql, handler, params);
> } finally {
> close(connection);
> }
> }
> public <T> T query(Connection connection, String sql,
> ResultSetHandler<T> handler, Object... params) throws SQLException {
> PreparedStatement statement = null;
> ResultSet resultSet = null;
> try {
> statement = this.prepareStatement(connection, sql);
> this.fillStatement(statement, params);
> resultSet = this.wrap(statement.executeQuery());
> return handler.handle(resultSet);
> } catch (SQLException e) {
> throw this.nestException(e, sql, params); //
> nestException creates an exception to be thrown here, instead of rethrow(e,
> sql, params);
> } finally {
> try {
> close(resultSet);
> } finally {
> close(statement);
> }
> }
> }
> I don't know for you, but I find that code much more readable and
> maintainable. In fact, I already did this implementation and use it in prod
> without any issue, since it is only basic language adaptation.
> And using it is also very easy:
> Book book = queryRunner.query("SELECT * FROM book WHERE title = ? AND author
> = ?", new BeanHandler(Book.class), title, author);
> instead of
> Book book = (Book)queryRunner.query("SELECT * FROM book WHERE title = ? AND
> author = ?", new BeanHandler(Book.class), new Object[]{title, author});
> However, I wrote an original time estimation of 1 day, because all classes
> have to be adapted, especially those included in
> org.apache.common.dbutils.handlers.
> As I estimate, it is minor, it is just a request in order to have more
> beautiful code, for a downside of providing a Java 1.5 compatible version of
> DBUtils. Maintaining this should be very rough as well, since DBUtils is not
> really big (but it's amazing how so little code can provide so much code
> improvements!)
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