Tokenizer debug

1. This class is identified as a Thread safe class. But the thread safety is being mis-used here. 
setFile() and getFile() methods are synchronized. The getContent(), getContentWithoutUnicode() and saveContent() 
methods are not synchronized. So the  concurrent access by multiple threads could lead to invoke errors.
2. Exception handling has been totally ignored here. Here in this code we are using IO (Input / Output). Its important to have exception handling. 
    public synchronized String getContent() throws IOException {
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file), StandardCharsets.UTF_8))) {
            StringBuilder output = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                output.append(line).append(System.lineSeparator());
            }
            return output.toString();
        }
    }
 3.. Misuse of String Concatenation. Its very important to use StringBuilder in cases like this. This code generates new String objects 
 in the way how it is now. A very primitive way of memory management.
 StringBuilder output = new StringBuilder();
  while ((data = i.read()) > 0) {
      output.append((char) data);
  }
  return output.toString();
  
  4..FileInputStream & FileOutputStream are not closed. This can be a significant resource leak. Better to wrap them in a Try,Catch in 
  order to automatically close streams after they are used.
  
  5. Handle File encoding. This class cannot handle multi-byte characters. It is not adviced to use  raw byte streams without 
  Character Encoding Handling.
  
  6. Need to Explicitly specify UTF-8 character encoding to avoid issues with different encodings.