FlightSqlClient Java Example

### Describe the usage question you have. Please include as many useful details as possible.

Hello,
I am trying to increase adoption of the Java FlightSqlClient by providing examples of how to connect to a server with it, execute a query, and return the result.
I’ve tried the following:

package com.example.helloworld;

// Import Apache Arrow Flight SQL classes
import org.apache.arrow.flight.*;
import org.apache.arrow.flight.sql.FlightSqlClient;
import org.apache.arrow.memory.BufferAllocator;
import org.apache.arrow.memory.RootAllocator;
import org.apache.arrow.vector.VectorSchemaRoot;
import io.grpc.Metadata;
import java.net.URI;

public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
String host = "us-east-1-1.aws.cloud2.influxdata.com";
String query = "SELECT * FROM \"airSensors\"";
Location location = Location.forGrpcInsecure(host, 443).forGrpcTls(host, 0);

// BufferAllocator allocator = new RootAllocator(Long.MAX_VALUE);

// FlightClient flightClient = FlightClient.builder().build();

CallHeaders headers = new FlightCallHeaders();
headers.insert("token", "xxx==");
headers.insert("bucket-name", "anais-iox");
HeaderCallOption headerOption = new HeaderCallOption(headers);
BufferAllocator allocator = new RootAllocator(Long.MAX_VALUE);

try {
client = FlightClient.builder()
.location(location)
.build();
System.out.println(client);
FlightSqlClient sqlClient = new FlightSqlClient(client);
System.out.println(sqlClient);
FlightInfo flightInfo = sqlClient.execute(query, headerOption);
FlightEndpoint endpoint = flightInfo.getEndpoints().get(0);
Ticket ticket = endpoint.getTicket();
System.out.println("Hello, World!");
} catch (Exception e) {
System.out.println("Error creating FlightClient: " + e.getMessage());
}

}
}
But I get Client cannot be null!

Additionally I’ve tried to pass in the allocator into the build method:

FlightClient client = FlightClient.builder(allocator, location).build();
But I’m not having success with that either.
Does anyone here have an example of how to use the FlightSqlClient? Or can identify what I’m doing wrong here? Thank you in advance for any pointers or help. I greatly appreciate it.

### Component(s)

Java

Beginne mit der im Issue gezeigten Verwendung von Java FlightClient.builder und verfolge anschließend, wie FlightSqlClient erstellt wird und wie execute(query, headerOption) FlightInfo zurückgibt. Überprüfe den Allocator, den Standort, die Header und die Client-Initialisierung in einem vollständigen Beispiel und bestätige, dass eine Verbindung hergestellt, die Abfrage ausgeführt und das Ergebnis zurückgegeben wird.

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