结果计数

Sometimes, a query might produce too many answers and you want to limit the number of answers returned. You can do this by using the count limit search control. By default, a search does not have a count limit--it will return all answers that it finds. To set the count limit of a search, pass the number to SearchControls.setCountLimit().

The following examplesets the count limit to 1.

// Set the search controls to limit the count to 1
SearchControls ctls = new SearchControls();
ctls.setCountLimit(1);

If the program attempts to get more than the count limit number of results, then a SizeLimitExceededException will be thrown. So if a program has set a count limit, then it should either differentiate this exception from other NamingExceptions or keep track of the count limit and not request more than that number of results.

Specifying a count limit for a search is one way of controlling the resources (such as memory and network bandwidth) that your application consumes. Other ways to control the resources consumed are to narrow your search filter (be more specific about what you seek), start your search in the appropriate context, and use the appropriate scope.