how to parse unicode that is read from a file in java [duplicate]

Answer 1

You want to use sun.tools.native2ascii to reverse convert the text.

new sun.tools.native2ascii.Main().convert(new String[]{"-reverse", new File("README.TXT"), convertedFile});

So something like this will do it.

public static void main(String[] args) throws Exception{
   File convertedFile = new File("converted.txt");
   new sun.tools.native2ascii.Main().convert(new String[]{"-reverse", new File("README.TXT"), convertedFile});
   FileInputStream fr = new FileInputStream(convertedFile);
   BufferedReader br = new BufferedReader(new InputStreamReader(fr,"UTF-8"));
   String s="";
   while((s=br.readLine())!=null){
      System.out.println(s);
    }
}

Answer 2

You can use the source code posted here to do unescaping.

Answer 3

The parsing of unicode escape sequences is not an explicit part of the Java Standard API, it only implicitly occurs when loading Properties. You could copy the implementation from the source code of Properties.

But it would be better to use a normal encoding like UTF-8 for your file.