Reusing a PreparedStatement

问题:

I ran findbugs on our code base and it pointed out there are two more Statements that still need to be closed. In this section of the code we run:

preparedStatement = connection.prepareStatement(query);

for 3 different queries, reusing preparedStatement. In the finally block we do close the resource:

finally{
   try{
      if (resultSet != null) 
         resultSet.close();
   } catch (Exception e) {
      exceptionHandler.ignore(e);
   }
   try {
      if (preparedStatement != null) 
         preparedStatement.close();
   } catch(Exception e) {
      exceptionHandler.ignore(e);
   }

Should the statement be closed before the next connection.prepareStatement(query); or is this findbugs being cautious?

回答1:

Yes, the statement must be closed before you perform the next connection.prepareStatement. Otherwise, you're losing your reference to the un-closed previous one (aka leaking statements). Wrap a try {} finally {} around each statement use, closing it in the finally.