[jira] [Created] (JCR-3487) Provide a utility to run JCR queries adopting a fluent-interfaces approach

["Simone Tripodi (JIRA)" <ji...@apache.org>]

Simone Tripodi created JCR-3487:
-----------------------------------

             Summary: Provide a utility to run JCR queries adopting a fluent-interfaces approach
                 Key: JCR-3487
                 URL: https://issues.apache.org/jira/browse/JCR-3487
             Project: Jackrabbit Content Repository
          Issue Type: Improvement
          Components: jackrabbit-jcr-commons
            Reporter: Simone Tripodi
            Priority: Minor


(moving the discussion from OAK-529)

I propose an approach that, without altering the current codebase, but rather adding a new package on top of existing APIs, tries to simplify the query building and execution, i.e. rather than coding the following:

{code}
QueryManager qm = session.getWorkspace().getQueryManager();
Query q = qm.createQuery("select text from [nt:base] where id = $id", Query.JCR_SQL2);
q.bindValue("id", vf.createValue("1"));
QueryResult r = q.execute();

String text = null;

RowIterator it = r.getRows();
if (it.hasNext()) {
    Row row = it.nextRow();
    text = row.getValue("text").getString();
}
{code}

users could write the same sentence using a shortcut like

{code}
String text = on(qm)
              .sql2Query("select text from [nt:base] where id = $id")
              .where("id").is("1")
              .execute(textHandler);
{code}

where {{textHandler}} is:

{code}
QueryResultHandler<String> textHandler = new QueryResultHandler<String> {

    @Override
    public String handle(QueryResult queryResult)
            throws RepositoryException {

        RowIterator it = queryResult.getRows();
        if (it.hasNext()) {
            Row row = it.nextRow();
            return row.getValue("text").getString();
        }

        return null;
    }

}
{code}

the {{QueryResultHandler}} should simplify reducing redundant query handling code, improving reusability.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira