Uploading a file of any type and size:
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bos = new BufferedOutputStream(new FileOutputStream(new File(
file.getAbsolutePath() + File.separator
+ event.getFile().getFileName())));

bis = new BufferedInputStream(event.getFile().getInputstream());
byte[] b = new byte[bis.available()];

while (bis.read(b) != -1)
bos.write(b);
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File file = new File("test.txt");
   FileReader fileReader = new FileReader(file);
   BufferedReader bufferedReader = new BufferedReader(fileReader);
   StringBuffer stringBuffer = new StringBuffer();
   String line;
   while ((line = bufferedReader.readLine()) != null) {
    stringBuffer.append(line);
    stringBuffer.append("\n");