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

issue に示されている Java FlightClient.builder の使用方法から始め、FlightSqlClient がどのように構築され、execute(query, headerOption) がどのように FlightInfo を返すかを追跡します。完全な例で allocator、location、headers、client の初期化を検証し、接続してクエリを実行し、結果を返すことを確認します。

索引モデルが issue の本文から書いたものです。