As per my understanding the use of PreparedStatement in Java is we can use it multiple times. But I have some confusion using PreparedStatementCreator of Spring JDBC.
For example consider following code,
public class SpringTest {
JdbcTemplate jdbcTemplate;
PreparedStatementCreator preparedStatementCreator;
ResultSetExtractor<String> resultSetExtractor;
public SpringTest() throws SQLException {
jdbcTemplate = new JdbcTemplate(OracleUtil.getDataSource());
preparedStatementCreator = new PreparedStatementCreator() {
String query = "select NAME from TABLE1 where ID=?";
public PreparedStatement createPreparedStatement(Connection connection) throws SQLException {
return connection.prepareStatement(query);
}
};
resultSetExtractor = new ResultSetExtractor<String>() {
public String extractData(ResultSet resultSet) throws SQLException,
DataAccessException {
if (resultSet.next()) {
return resultSet.getString(1);
}
return null;
}
};
}
public String getNameFromId(int id){
return jdbcTemplate.query(preparedStatementCreator, new Table1Setter(id), resultSetExtractor);
}
private static class Table1Setter implements PreparedStatementSetter{
private int id;
public Table1Setter(int id) {
this.id =id;
}
@Override
public void setValues(PreparedStatement preparedStatement) throws SQLException {
preparedStatement.setInt(1, id);
}
}
public static void main(String[] args) {
try {
SpringTest springTest = new SpringTest();
for(int i=0;i<10;i++){
System.out.println(springTest.getNameFromId(i));
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
As per this code when I called springTest.getNameFromId(int id) method, it returns name from given id, Here I've used PreparedStatementCreator for creating PreparedStatement and PreparedStatementSetter for setting input parameters and I got result from ResultSetExtractor. But performance is very slow.
After debugging and looking into what happens inside PreparedStatementCreator and JdbcTemplate I got to know that PreparedStatementCreator creates each and every time new PreparedStatement...!!!
Each and every time when I am calls method jdbcTemplate.query(preparedStatementCreator, preparedStatementSetter, resultSetExtractor), it creates new PreparedStatement and this slow downs performance.
Is this right way to use PreparedStatementCreator? Because in this code I unable to reuse PreparedStatement. And if this is right way to use PreparedStatementCreator than how to get benefit of re-usability of PreparedStatement?
You are on the right way to use PreparedStatementCreator.
To summarize, what you did is correct. use PreparedStatement will have better performance than Statement.