ChronoLocalDate query() Method in Java with Examples

query() method of an ChronoLocalDate interface used to query this ChronoLocalDate using the specified query as parameter. The TemporalQuery object passed as parameter define the logic to be used to obtain the result from this ChronoLocalDate.

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
// ChronoLocalDate.query() method

import java.time.*;
import java.time.temporal.*;
import java.time.chrono.*;

public class GFG {
    public static void main(String[] args)
    {

        // create ChronoLocalDate object
        ChronoLocalDate ld = LocalDate.parse("2018-12-31");

        // apply the query method of ChronoLocalDate class
        String value
            = ld.query(TemporalQueries.precision())
                  .toString();

        // print the result
        System.out.println("Precision value for ChronoLocalDate is "
                           + value);
    }
}

Output:

Precision value for ChronoLocalDate is Days

Program 2: Showing if query did not found the required object then it returns null.

// Java program to demonstrate
// ChronoLocalDate.query() method

import java.time.*;
import java.time.temporal.*;
import java.time.chrono.*;

public class GFG {
    public static void main(String[] args)
    {

        // create ChronoLocalDate object
        ChronoLocalDate ld = LocalDate.parse("2018-12-31");

        // apply query method of ChronoLocalDate class
        // print the result
        System.out.println("Zone value for ChronoLocalDate is "
                           + ld.query(
                                 TemporalQueries.offset()));
    }
}

Output:

Zone value for ChronoLocalDate is null

References:
https://docs.oracle.com/javase/9/docs/api/java/time/chrono/ChronoLocalDate.html#query-java.time.temporal.TemporalQuery-