LocalDateTime query() Method in Java with Examples

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

// 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

// 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

References: https://docs.oracle.com/javase/10/docs/api/java/time/LocalDateTime.html#query(java.time.temporal.TemporalQuery)

LocalDateTime query() Method in Java with Examples

Explore