VeriFactu en Java

import java.net.http.*;
import java.net.URI;
import java.math.BigDecimal;

// Un text block de Java (tres comillas) evita escapar el JSON.
String cuerpo = """
  {
    "emisor":   { "nif": "B12345678" },
    "numero":   "F2026/0184",
    "fecha":    "2026-08-26",
    "tipo":     "F1",
    "base":     100.00,
    "cuota":      7.00,
    "total":    107.00,
    "impuesto": "IGIC"
  }
  """;

var req = HttpRequest.newBuilder()
    .uri(URI.create("https://api.verifactu.co/v1/registros"))
    .header("Authorization", "Bearer " + System.getenv("VERIFACTU_KEY"))
    .header("Content-Type", "application/json")
    .header("Idempotency-Key", "F2026/0184")
    .POST(HttpRequest.BodyPublishers.ofString(cuerpo))
    .timeout(java.time.Duration.ofSeconds(15))
    .build();

var res = HttpClient.newHttpClient()
    .send(req, HttpResponse.BodyHandlers.ofString());

if (res.statusCode() >= 400) {
    throw new RuntimeException(res.body());
}

// Para los importes: BigDecimal, nunca double.
System.out.println(res.body());