Java无法打印双面

有一段提取的代码可以双面打印

aset.add(new Copies(1));
aset.add(MediaSizeName.ISO_A4);
aset.add(Sides.DUPLEX);
aset.add(Sides.TWO_SIDED_LONG_EDGE);
printJob.print(printDocument, aset);

然而，这一切都是片面的。我的打印机可以与其他应用程序一起双面打印。然而，它只是不想用Java打印双面。感谢您的帮助。谢谢

更新：我在doc flavor上运行了一个打印。这是我所需打印机的摘录：

            PrintService[] services = PrintServiceLookup.lookupPrintServices(null, null);
            for (PrintService ps: services) {
                System.out.println(ps + " supports :");
                DocFlavor[] flavors = ps.getSupportedDocFlavors();
                for (DocFlavor fl : flavors ){
                    System.out.println("\tFlavor:" + fl.toString());
                    System.out.println("\tMime Type:" + fl.getMimeType());
                    System.out.println("\tMediaType Type:" + fl.getMediaType());
                }

            }

输出：

  Flavor:image/gif; class="[B"
  Mime Type:image/gif
  MediaType Type:image
  Flavor:image/gif; class="java.io.InputStream"
  Mime Type:image/gif
  MediaType Type:image
  Flavor:image/gif; class="java.net.URL"
  Mime Type:image/gif
  MediaType Type:image
  Flavor:image/jpeg; class="[B"
  Mime Type:image/jpeg
  MediaType Type:image
  Flavor:image/jpeg; class="java.io.InputStream"
  Mime Type:image/jpeg
  MediaType Type:image
  Flavor:image/jpeg; class="java.net.URL"
  Mime Type:image/jpeg
  MediaType Type:image
  Flavor:image/png; class="[B"
  Mime Type:image/png
  MediaType Type:image
  Flavor:image/png; class="java.io.InputStream"
  Mime Type:image/png
  MediaType Type:image
  Flavor:image/png; class="java.net.URL"
  Mime Type:image/png
  MediaType Type:image
  Flavor:application/x-java-jvm-local-objectref; class="java.awt.print.Pageable"
  Mime Type:application/x-java-jvm-local-objectref
  MediaType Type:application
  Flavor:application/x-java-jvm-local-objectref; class="java.awt.print.Printable"
  Mime Type:application/x-java-jvm-local-objectref
  MediaType Type:application
  Flavor:application/octet-stream; class="[B"
  Mime Type:application/octet-stream
  MediaType Type:application
  Flavor:application/octet-stream; class="java.net.URL"
  Mime Type:application/octet-stream
  MediaType Type:application
  Flavor:application/octet-stream; class="java.io.InputStream"
  Mime Type:application/octet-stream
  MediaType Type:application

似乎都是jpeg/gif/png图像类型。这是问题的原因吗？

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谢谢

代码的其余部分在哪里？例如，什么是资产，你从哪里得到这些枚举…嗨，我从文档中得到：你能在另一台打印机上重现这个问题吗？我看了一下这个例子，如果问题不在打印机上，可能是JPS中的一个bug，记录一个bug：Hi Jan Vladimir Mostert。这与其他打印机相同。我已经打印出了doc风格，并在我的帖子中进行了更新。谢谢