Question

This is a piece of code to output a PDF file to browser, could it be faster?
This is implemented in a Java servlet.

private ByteArrayOutputStream getByteArrayOutputStreamFromFile(File file) throws Exception {
        BufferedInputStream bis = null;
        ByteArrayOutputStream bos = null;
        try {
            bis = new BufferedInputStream(new FileInputStream(file));
            bos = new ByteArrayOutputStream();
            byte[] byteContent = new byte[1024 * 1024];
            int len = 0;
            while ((len = bis.read(byteContent)) != -1) {
                bos.write(byteContent, 0, len);
            }
            return bos;
        } catch (Exception ex) {
            throw ex;
        } finally {
            if (bis != null) {
                bis.close();
            }
            if (bos != null) {
                bos.close();
            }
        }
    }

Answer 1

Using Google Guava you can summarize this in one line:

import com.google.common.io.Files;

private OutputStream getOutputStream(File file) throws IOException {
    return Files.newOutputStreamSupplier(file).getOutput();
}