如何将HTML5文件类型转换为java。伊奥。在瓦丁归档？

Question

public void drop(DragAndDropEvent dropEvent) {

        WrapperTransferable tr = (WrapperTransferable) dropEvent.getTransferable();
        Html5File[] files = tr.getFiles();
        if (files != null) {
            for (final Html5File html5File : files) {
                final String fileName = html5File.getFileName();

                final ByteArrayOutputStream bas = new ByteArrayOutputStream();
                StreamVariable streamVariable = new StreamVariable() {

                        public OutputStream getOutputStream() {
                            return bas;
                        }
                        public boolean listenProgress() {
                            return false;
                        }
                        public void onProgress(StreamingProgressEvent event) {
                        }
                        public void streamingStarted(
                                StreamingStartEvent event) {
                        }
                        public void streamingFinished(
                                StreamingEndEvent event) {
                            progress.setVisible(false);
                            showFile(fileName, html5File.getType(), bas);
                        }
                        public void streamingFailed(
                                StreamingErrorEvent event) {
                            progress.setVisible(false);
                        }
                        public boolean isInterrupted() {
                            return false;
                        }
                    };
                    html5File.setStreamVariable(streamVariable);
                    progress.setVisible(true);


                    encryptAndUploadFile( ***html5File****, fileName, folderName);

//如何将这个HTML5文件转换为java。伊奥。因为我有一个encryptAndUploadFile方法，它接受File参数

                }
            }
     }

//encryptAndUploadFile（）方法

  public void encryptAndUploadFile(File file, String fileName,String folderName) 
  {
    String  m_strWebFilePath = finalSourcepath + fileName;
    File m_objFile=null;
    byte[] sourceFileByte = Encryption.aesEncrypt(com.saterisystems.common.utils.FileUtils.getImageIntoByteArray(file), GlobalConstants.KEY.getBytes(), GlobalConstants.IV.getBytes());
    ......
    ......
    ......

请建议我如何将这个HTML5文件类型的对象类型转换为java。伊奥。文件类型对象

Answer 1

编辑： 我再次阅读了他们的文档和演示代码。当使用Vaadin拖放文件时，实际的上传似乎由它来处理。真正的问题是，您希望在它们进入服务器（从您想要调用的方法）之前对它们进行加密

我想我找到了一种加密上传的方法。请看下面演示中的代码http://demo.vaadin.com/sampler/#ui/data-input/other/drop-items：

if (files != null) {
    for (final Html5File html5File : files) {
        final String fileName = html5File.getFileName();

        if (html5File.getFileSize() > FILE_SIZE_LIMIT) {
            Notification
                .show("File rejected. Max 2Mb files are accepted by Sampler",
                                          Notification.Type.WARNING_MESSAGE);
        } else {

            final ByteArrayOutputStream bas = new ByteArrayOutputStream();
            final StreamVariable streamVariable = new StreamVariable() {

                 @Override
                 public OutputStream getOutputStream() {
                      return bas;
                 }

                 @Override
                 public boolean listenProgress() {
                      return false;
                 }

                 @Override
                 public void onProgress(
                      final StreamingProgressEvent event) {
                 }

                 @Override
                 public void streamingStarted(
                      final StreamingStartEvent event) {
                 }

                 @Override
                 public void streamingFinished(
                      final StreamingEndEvent event) {
                      progress.setVisible(false);
                      showFile(fileName, html5File.getType(), bas);
                 }

                 @Override
                 public void streamingFailed(
                      final StreamingErrorEvent event) {
                      progress.setVisible(false);
                 }

                 @Override
                 public boolean isInterrupted() {
                      return false;
                 }
             };
             html5File.setStreamVariable(streamVariable);
             progress.setVisible(true);
        }
    }

} else {
     final String text = tr.getText();
     if (text != null) {
         showText(text);
     }
}

它似乎要求您为要发送到服务器的数据提供输出流。您可以对ByteArrayOutputStream类进行子类化，并重写write（byte[]b）方法，以便在数据到达超类write方法之前对其进行加密，如下所示：

public class EncryptedArrayOutputStream extends ByteArrayOutputStream {

@Override
public void write(byte[] b) throws IOException{
    byte[] encrypted = encrypt(b);
    super.write(encrypted);

}

private byte[] encrypt(byte[] bytes) {

    byte[] encrypted = new byte[bytes.length]; // This also might not be the size depending on the algorithm you choose
    // Your algorithm here....
    return encrypted;
}
}