query() method of an LocalDateTime class used to query this LocalDateTime using the specified query as parameter.The TemporalQuery object passed as parameter define the logic to be used to obtain the result from this LocalDateTime.
Syntax:
public <R> R query(TemporalQuery<R> query)
Parameters: This method accepts only one parameter query which is the query to invoke.
Return value: This method returns the query result, null may be returned.
Exception:This method throws following Exceptions:
- DateTimeException – if unable to query .
- ArithmeticException – if numeric overflow occurs.
Below programs illustrate the query() method:
Program 1:
// Java program to demonstrate// LocalDateTime.query() method  import java.time.*;import java.time.temporal.*;  public class GFG {    public static void main(String[] args)    {          // create LocalDateTime object        LocalDateTime lt            = LocalDateTime.parse(                "2018-10-25T23:12:31.123");          // apply query method of LocalDateTime class        String value            = lt.query(                    TemporalQueries.precision())                  .toString();          // print the result        System.out.println("Precision value"                           + " for LocalDateTime is "                           + value);    }} |
Output:
Precision value for LocalDateTime is Nanos
Program 2: Showing if query did not found the required object then it returns null.
// Java program to demonstrate// LocalDateTime.query() method  import java.time.*;import java.time.temporal.*;  public class GFG {    public static void main(String[] args)    {          // create LocalDateTime object        LocalDateTime lt            = LocalDateTime.parse(                "2018-10-25T23:12:31.123");          // apply query method of LocalDateTime class        // print the result        System.out.println("offset value "                           + "for LocalDateTime is "                           + lt.query(TemporalQueries.offset()));    }} |
Output:
offset value for LocalDateTime is null
