Need suggestions on this custom class

Question

I have a simple class (SQLTask) that generisizes execution of a INSERT/UPDATE/DELETE statement.
The main problem is that when the elements of the list
are null. I do not know the type/class of the null object
so as to bind it properly. In my bindNull method below
I bind it as stmt.setNull(n, Types.NULL) which does not
work. I don't want to change the ArrayList datastructure
because it really simplifies client calls.
Any suggestions?
public class SQLTask {
private static final Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("America/Chicago"));
private List params = new ArrayList();
private String sql;
public SQLTask(String sql, List params) {
this.sql = sql;
this.params = params;
public void save(Transaction tt) throws SQLException {
PreparedStatement stmt = tt.prepareStatement(sql);
int n = 1;
for (Iterator itr = params.iterator(); itr.hasNext(); ) {
Object value = itr.next();
bindParams(n++, stmt, value);
int rows = stmt.executeUpdate();
log.debug(rows+" were affected by the sql "+sql);
private void bindParams(int n,PreparedStatement stmt, Object value) throws SQLException {
if (value == null) {
bindNull(n, stmt, value);
return;
try {
if (value.getClass().equals(Integer.class)) {
stmt.setInt(n, ((Integer)value).intValue());
}else if (value.getClass().equals(Long.class)) {
stmt.setLong(n, ((Long)value).intValue());
}else if (value.getClass().equals(Float.class)) {
stmt.setFloat(n, ((Float)value).intValue());
}else if (value.getClass().equals(Double.class)) {
stmt.setDouble(n, ((Double)value).intValue());
}else if (value.getClass().equals(String.class)) {
stmt.setString(n, (String)value);
} else if (value.getClass().equals(Date.class)) {
stmt.setTimestamp(n, new java.sql.Timestamp(((Date)value).getTime()), calendar);
} catch(ClassCastException e) {
throw new SQLException("ClassCastException while binding parameters value "+value+" of class "+value.getClass());
private void bindNull(int n,PreparedStatement stmt, Object key) throws SQLException {
stmt.setNull(n, Types.NULL)

Answer 1

Where do you close the statement?
Where do you close the statement when there is an exception?
What happens to the connection when there is an exception?