Java Code Examples for javax.servlet.http.HttpServletResponse#setBufferSize()

/**
 * Copy the contents of the file to the servlet's outputstream.
 * 
 * @param response
 * @throws IOException
 */
private void copyContent(final HttpServletResponse response, final InputStream istream) throws IOException {

    // Copy resource to output stream
    ServletOutputStream ostream = null;
    try {
        response.setBufferSize(outputBufferSize);
        ostream = response.getOutputStream();

        int len;
        final byte buffer[] = new byte[inputBufferSize];
        while ((len = istream.read(buffer)) != -1) {
            ostream.write(buffer, 0, len);
        }
    } finally {
        istream.close();
    }
    ostream.flush();
}
 

/**
 * Copy the contents of the file to the servlet's outputstream.
 * 
 * @param response
 * @throws IOException
 */
private void copyContent(final HttpServletResponse response, final InputStream istream) throws IOException {

    // Copy resource to output stream
    ServletOutputStream ostream = null;
    try {
        response.setBufferSize(outputBufferSize);
        ostream = response.getOutputStream();

        int len;
        final byte buffer[] = new byte[inputBufferSize];
        while ((len = istream.read(buffer)) != -1) {
            ostream.write(buffer, 0, len);
        }
    } finally {
        istream.close();
    }
    ostream.flush();
}
 

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
    resp.setBufferSize(bufferSize);

    resp.setContentType("text/plain");
    resp.setCharacterEncoding("UTF-8");
    resp.setContentLength(responseSize);

    PrintWriter pw = resp.getWriter();
    for (int i = 0; i < responseSize; i++) {
        pw.append('X');
    }
}
 

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
    resp.setBufferSize(bufferSize);

    resp.setContentType("text/plain");
    resp.setCharacterEncoding("UTF-8");
    resp.setContentLength(responseSize);

    PrintWriter pw = resp.getWriter();
    for (int i = 0; i < responseSize; i++) {
        pw.append('X');
    }
}
 

/**
 * 导出
 * @param modelName 模型名称
 * @param excelType excel格式
 * @param response
 * @return
 * @throws IOException
 */
@RequestMapping(value = { "/excel/{modelName}","/excel/{modelName}/{excelType}" }, method = RequestMethod.GET)
public void exportExcel(@PathVariable String modelName,@PathVariable(required = false) String excelType, HttpServletResponse response) throws IOException {
    //默认导出xls格式excel
    if(excelType==null||"".equals(excelType)){
        excelType="XLS";
    }
    List<SysExportModel> models = modelService.queryExportModelByCondition(modelName);
    // 模型不存在 直接结束
    if (models == null || models.size() == 0) {
        return;
    }
    // 获取导出数据
    SysExportModel model = models.get(0);
    List<List<Object>> exportData = commonService.getAllData(model.getModelName(), model.getEnames(), null);
    List<String> exportHeaderNames = new ArrayList<String>();
    String[] headerNames = model.getCnames().split(",");
    for (String headerName : headerNames) {
        exportHeaderNames.add(headerName);
    }

    response.reset();
    // 文件下载
    response.setContentType("application/vnd.ms-excel");
    String filename = "报表"+modelName+"（"+ new SimpleDateFormat("yyyyMMddHHmmss").format(new Date())+ "）";

    filename = new String(filename.getBytes("gbk"), "iso-8859-1");
    response.setHeader("Content-disposition", "attachment;filename="+ filename + "."+excelType.toLowerCase());
    response.setBufferSize(1024);

    //获取excel表单
    ExcelGenerater excelGenerater=new ExcelGenerater();
    ExcelGeneraterBean excelGeneraterBean = excelGenerater.create(modelName, exportHeaderNames, exportData);
    Workbook workbook = excelGeneraterBean.getWorkbook();
    //写入数据 到流
    workbook.write(response.getOutputStream());
    workbook.close();
}
 

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
    resp.setBufferSize(bufferSize);

    resp.setContentType("text/plain");
    resp.setCharacterEncoding("UTF-8");
    resp.setContentLength(responseSize);

    PrintWriter pw = resp.getWriter();
    for (int i = 0; i < responseSize; i++) {
        pw.append('X');
    }
}
 

/**
 * Sends content by copying all bytes from the input stream to the response setting the preferred buffer
 * size. At the end, it flushes response buffer. Passed in {@link InputStream} is fully consumed and closed.
 * The passed in {@link HttpServletResponse} after this call returns is committed and flushed.
 */
public static void sendContent(final InputStream input, final HttpServletResponse response) throws IOException {
  int bufferSize = BUFFER_SIZE;
  if (bufferSize < 1) {
    // if no user override, ask container for bufferSize
    bufferSize = response.getBufferSize();
    if (bufferSize < 1) {
      bufferSize = 8192;
      response.setBufferSize(bufferSize);
    }
  }
  else {
    // user override present, tell container what buffer size we'd like
    response.setBufferSize(bufferSize);
  }
  try (final InputStream from = input; final OutputStream to = response.getOutputStream()) {
    final byte[] buf = new byte[bufferSize];
    while (true) {
      int r = from.read(buf);
      if (r == -1) {
        break;
      }
      to.write(buf, 0, r);
    }
    response.flushBuffer();
  }
}
 

private String doDownload() {
    String errorMsg = null;
    DocStoreClient client = ResourceManager.getInstance().getClients().getDocStoreClient();
    if (client != null) {
        try {
            YDocument doc = client.getDocument(docID, client.getHandle());
            if (doc.getDocument() != null) {
                FacesContext context = FacesContext.getCurrentInstance();
                HttpServletResponse response =
                        ( HttpServletResponse ) context.getExternalContext().getResponse();
                response.setContentType("multipart/form-data");
                response.setBufferSize(doc.getDocumentSize());
                response.setHeader("Content-Disposition",
                        "attachment;filename=\"" + docName + "\"");
                OutputStream os = response.getOutputStream();
                os.write(doc.getDocument());
                os.flush();
                os.close();
                FacesContext.getCurrentInstance().responseComplete();
            }
            else errorMsg = "Unable to download document: unknown document id.";
        }
        catch (IOException ioe) {
            errorMsg = "Unable to download document. Please see the log for details.";
        }
    }
    else errorMsg = "Unable to download document: missing Document Store.";

    return errorMsg;
}
 

/**
 * Writes a binary file to a response's output stream
 *
 * @param res the response
 * @param doc a YDocument wrapper containing the binary file
 * @throws IOException if there's a problem writing to the stream
 */
private void writeDocument(HttpServletResponse res, YDocument doc) throws IOException {
    if (doc != null) {
        res.setContentType("multipart/form-data");
        res.setBufferSize(doc.getDocumentSize());
        ServletOutputStream out = res.getOutputStream();
        out.write(doc.getDocument());
        out.flush();
        out.close();
    }
}
 

/**
 * Copy the contents of the specified input stream to the specified output stream, and ensure that
 * both streams are closed before returning (even in the face of an exception).
 *
 * @param repoItemHttpElem
 *          The cache entry for the source resource
 * @param response
 *          The response we are writing to
 * @param range
 *          Range asked by the client
 * @exception IOException
 *              if an input/output error occurs
 */
protected void copy(RepositoryHttpEndpointImpl repoItemHttpElem, HttpServletResponse response,
    Range range) throws IOException {

  try {
    response.setBufferSize(OUTPUT_BUFFER_SIZE);
  } catch (IllegalStateException e) {
    // Silent catch
  }

  IOException exception;

  try (ServletOutputStream ostream = response.getOutputStream()) {
    try (InputStream istream = new BufferedInputStream(
        repoItemHttpElem.createRepoItemInputStream(), INPUT_BUFFER_SIZE)) {

      if (range != null) {
        exception = copyStreamsRange(istream, ostream, range);
      } else {
        exception = copyStreams(istream, ostream);
      }

    }
  }

  // Rethrow any exception that has occurred
  if (exception != null) {
    throw exception;
  }
}
 

/**
 * <p>
 * Write response with target relation and publishes events concerning the
 * download progress based on given update action status.
 * </p>
 *
 * <p>
 * The request supports RFC7233 range requests.
 * </p>
 *
 * @param artifact
 *            the artifact
 * @param filename
 *            to be written to the client response
 * @param lastModified
 *            unix timestamp of the artifact
 * @param response
 *            to be sent back to the requesting client
 * @param request
 *            from the client
 * @param progressListener
 *            to write progress updates to
 *
 * @return http response
 *
 * @see <a href="https://tools.ietf.org/html/rfc7233">https://tools.ietf.org
 *      /html/rfc7233</a>
 * 
 * @throws FileStreamingFailedException
 *             if streaming fails
 */
public static ResponseEntity<InputStream> writeFileResponse(final AbstractDbArtifact artifact,
        final String filename, final long lastModified, final HttpServletResponse response,
        final HttpServletRequest request, final FileStreamingProgressListener progressListener) {

    ResponseEntity<InputStream> result;

    final String etag = artifact.getHashes().getSha1();
    final long length = artifact.getSize();

    response.reset();
    response.setHeader(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=" + filename);
    response.setHeader(HttpHeaders.ETAG, etag);
    response.setHeader(HttpHeaders.ACCEPT_RANGES, "bytes");
    // set the x-content-type options header to prevent browsers from doing
    // MIME-sniffing when downloading an artifact, as this could cause a
    // security vulnerability
    response.setHeader(com.google.common.net.HttpHeaders.X_CONTENT_TYPE_OPTIONS, "nosniff");
    if (lastModified > 0) {
        response.setDateHeader(HttpHeaders.LAST_MODIFIED, lastModified);
    }

    response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
    response.setBufferSize(BUFFER_SIZE);

    final ByteRange full = new ByteRange(0, length - 1, length);
    final List<ByteRange> ranges = new ArrayList<>();

    // Validate and process Range and If-Range headers.
    final String range = request.getHeader("Range");
    if (lastModified > 0 && range != null) {
        LOG.debug("range header for filename ({}) is: {}", filename, range);

        // Range header matches"bytes=n-n,n-n,n-n..."
        if (!range.matches("^bytes=\\d*-\\d*(,\\d*-\\d*)*$")) {
            response.setHeader(HttpHeaders.CONTENT_RANGE, "bytes */" + length);
            LOG.debug("range header for filename ({}) is not satisfiable: ", filename);
            return new ResponseEntity<>(HttpStatus.REQUESTED_RANGE_NOT_SATISFIABLE);
        }

        // RFC: if the representation is unchanged, send me the part(s) that
        // I am requesting in
        // Range; otherwise, send me the entire representation.
        checkForShortcut(request, etag, lastModified, full, ranges);

        // it seems there are valid ranges
        result = extractRange(response, length, ranges, range);
        // return if range extraction turned out to be invalid
        if (result != null) {
            return result;
        }
    }

    // full request - no range
    if (ranges.isEmpty() || ranges.get(0).equals(full)) {
        LOG.debug("filename ({}) results into a full request: ", filename);
        result = handleFullFileRequest(artifact, filename, response, progressListener, full);
    }
    // standard range request
    else if (ranges.size() == 1) {
        LOG.debug("filename ({}) results into a standard range request: ", filename);
        result = handleStandardRangeRequest(artifact, filename, response, progressListener, ranges);
    }
    // multipart range request
    else {
        LOG.debug("filename ({}) results into a multipart range request: ", filename);
        result = handleMultipartRangeRequest(artifact, filename, response, progressListener, ranges);
    }

    return result;
}
 

/**
 * Copy the contents of the specified input stream to the specified output stream, and ensure that
 * both streams are closed before returning (even in the face of an exception).
 *
 * @param repoItemHttpElem
 *          The cache entry for the source resource
 * @param response
 *          The response we are writing to
 * @param ranges
 *          Enumeration of the ranges the client wanted to retrieve
 * @param contentType
 *          Content type of the resource
 * @exception IOException
 *              if an input/output error occurs
 */
protected void copy(RepositoryHttpEndpointImpl repoItemHttpElem, HttpServletResponse response,
    List<Range> ranges, String contentType) throws IOException {

  try {
    response.setBufferSize(OUTPUT_BUFFER_SIZE);
  } catch (IllegalStateException e) {
    // Silent catch
  }

  IOException exception = null;
  try (ServletOutputStream ostream = response.getOutputStream()) {

    for (Range currentRange : ranges) {

      try (InputStream istream = new BufferedInputStream(
          repoItemHttpElem.createRepoItemInputStream(), INPUT_BUFFER_SIZE)) {

        // Writing MIME header.
        ostream.println();
        ostream.println("--" + MIME_SEPARATION);

        if (contentType != null) {
          ostream.println("Content-Type: " + contentType);
        }

        ostream.println("Content-Range: bytes " + currentRange.start + "-" + currentRange.end
            + "/" + currentRange.length);
        ostream.println();

        exception = copyStreamsRange(istream, ostream, currentRange);

        if (exception != null) {
          break;
        }
      }
    }

    ostream.println();
    ostream.print("--" + MIME_SEPARATION + "--");
  }
  // Rethrow any exception that has occurred
  if (exception != null) {
    throw exception;
  }

}