CODEWITHSUNDEEP
javajava-7jdbctemplatespring-3
Rache
Rache

Reputation: 217

jdbcTemplate.query(PreparedStatementCreator psc, ResultSetExtractor<T> rse) does not return any resultset

I am in the process of converting creation of connection to use JdbcTemplate class which handles the creation and release of resources. One of the implementation shown below is not returning me a resultset though the original one for the same query returns me records. I converted the below code 

ps = connection.prepareStatement(strQuery, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
ps.setLong(1, getId());
objRs = ps.executeQuery();

to the one shown below. The reason I used a StreamingStatementCreator was because I needed to set ResultSet.TYPE_SCROLL_INSENSITIVE and ResultSet.CONCUR_READ_ONLY.

objRs = (ResultSet) jdbcTemplate.query(new StreamingStatementCreator(strQuery),
        new PreparedStatementSetter() {
            public void setValues(PreparedStatement preparedStatement) throws SQLException {
                preparedStatement.setLong(1, getId());
            }
        }, new CustomResultSetExtractor());

public class CustomResultSetExtractor implements ResultSetExtractor<ResultSet>{
    public ResultSet extractData(ResultSet resultSet) throws SQLException, DataAccessException {
        return resultSet;
    }
}

I am not familiar with these methods. I tried to look for examples and I feel the code is correct by maybe I missing something. The first case returns me value in objRs and the second returns me nothing.

Upvotes: 0

Views: 1586

Answers (2)

Rache
Rache

Reputation: 217

Based on the clue by Alexander, made use of the ColumnMapRowMapper to iterate the result set. Since I wanted a generic solution that I could use for all my queries, instead of processing the resultset in my CustomResultSetExtractor or create separate classes. I am adding the code here so that anyone else who comes across this same situation may find it useful. 

public class CustomResultSetExtractor implements ResultSetExtractor<Object>{

    private RowMapper<Map<String, Object>> mapper;

    public CustomResultSetExtractor(ColumnMapRowMapper mapper) {
       this.mapper = mapper;
    }

    public List<Map<String, Object>> extractData(ResultSet rs) throws SQLException, DataAccessException {
        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
        int row = 0;
        while(rs.next()){  
            Map<String, Object> o = (Map<String, Object>)mapper.mapRow(rs, row++);
            list.add(o);
        }
        return list;
    }
}

Upvotes: 0

Alexander Kudrevatykh
Alexander Kudrevatykh

Reputation: 870

Method query(PreparedStatementCreator psc, ResultSetExtractor<T> rse) Does not returns ResultSet. It calls second parameter with ResultSet as argument and returns object that was returned by it.

So you shoud process ResultSet in CustomResultSetExtractor and return onther object as a result of processing.

Upvotes: 1

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