HTTP/2 Client Sample

HttpResponseUtils.java

public class HttpResponseUtils {
    public static HttpResponse.BodyHandler<Path> createHandler(Path path) {
        return (status, headers) -> {
            return headers.firstValue("Content-Disposition")
                          .map(header -> {
                              if (header.startsWith("attachment;")) {
                                  return Arrays.stream(header.split(";"))
                                               .map(item -> item.trim())
                                               .filter(item -> item.startsWith("filename="))
                                               .findFirst()
                                               .map(f -> {
                                                   int index = f.indexOf("=") + 1;
                                                   Path newPath = path.getParent().resolve(f.substring(index));
                                                   return HttpResponse.BodyProcessor.asFile(newPath);
                                               }).orElseThrow(() -> new UncheckedIOException(new IOException("No Filename")));
                              } else if (header.startsWith("inline")){
                                  return HttpResponse.BodyProcessor.asFile(path);
                              } else {
                                  throw new UncheckedIOException(new IOException("No Attachment"));
                              }
                          }).orElse(HttpResponse.BodyProcessor.asFile(path));
        };
    }
}

HTTPのヘッダのContent-Dispositionがattachmentかinlineかを判別してダウンロードする HttpResponse.BodyHandler を作成するためのメソッド