As we saw in the Setting a request body and Handling response body types sections, the HTTP Client API can send and receive text and binary data (for example, images, videos, and so on).

Downloading a file relies on the following two coordinates:

• Sending a GET request
• Handling the received bytes (for example, via BodyHandlers.ofFile())

The following code downloads hibernate-core-5.4.2.Final.jar from the Maven repository in the project classpath:

HttpClient client = HttpClient.newHttpClient();

HttpRequest request = HttpRequest.newBuilder()
  .uri(URI.create("http://.../hibernate-core-5.4.2.Final.jar"))
  .build();

HttpResponse<Path> response 
  = client.send(request, HttpResponse.BodyHandlers.ofFile(
    Path.of("hibernate-core-5.4.2.Final.jar")));

If the resource to download is delivered via the Content-Disposition HTTP header, which is of the Content-Disposition attachment; filename="..." type, then we can rely on BodyHandlers.ofFileDownload(), as in the following example:

import static java.nio.file.StandardOpenOption.CREATE;
...
HttpClient client = HttpClient.newHttpClient();

HttpRequest request = HttpRequest.newBuilder()
  .uri(URI.create("http://...downloadfile.php
    ?file=Hello.txt&cd=attachment+filename"))
  .build();

HttpResponse<Path> response = client.send(request,
  HttpResponse.BodyHandlers.ofFileDownload(Path.of(
    System.getProperty("user.dir")), CREATE));

More files that can be tested are available here: http://demo.borland.com/testsite/download_testpage.php.