javajdbcresource-management

Where to close java PreparedStatements and ResultSets?

Consider the code:

PreparedStatement ps = null;
ResultSet rs = null;
try {
  ps = conn.createStatement(myQueryString);
  rs = ps.executeQuery();
  // process the results...
} catch (java.sql.SQLException e) {
  log.error("an error!", e);
  throw new MyAppException("I'm sorry. Your query did not work.");
} finally {
  ps.close();
  rs.close();
}

The above does not compile, because both PreparedStatement.close() and ResultSet.close() throw a java.sql.SQLException. So do I add a try/catch block to the finally clause? Or move the close statements into the try clause? Or just not bother calling close?

Solution

  • For file I/O, I generally add a try/catch to the finally block. However, you must be careful not to throw any exceptions from the finally block, since they will cause the original exception (if any) to be lost.

    See this article for a more specific example of database connection closing.