在java中读取文本文件时的垃圾字符

Question

I have a java which calls windows bat file which does some processing and generates the output file.
Process p = Runtime.getRuntime().exec("cmd /c "+filename);
Now when reading the file from following program. ( filexists() is function which checks whether file exists or not). Output file contains only single line

if ( filexists("output.txt") == true)    
{   String FileLine; 
    FileInputStream fstream = new FileInputStream("output.txt");
    BufferedReader br = new BufferedReader(new InputStreamReader(fstream));

    FileLine = br.readLine();
    fstream.close();
    filein.close();

}

Variable FileLine contains 3 junk charcters in the starting. I also checked few other files in the progam and no file has this issue except for the fact it is created with Runtime function.
9087 .
As you can see three junk characters are coming in the output file. When opened with Notepad++, i am not able to see those junk characters.

Please suggest

Answer 1

This is happening because you have not mentioned the file encoding while creating your FileInputStream.Assuming your file is UTF-8 encoded, you need to do something like this

   new FileInputStream("output.txt, "UTF-8"));

Change the encoding as per the encoding of your file

Answer 2

That looks like the byte order mark for UTF-8 encoding. See https://en.wikipedia.org/wiki/Byte_order_mark

Answer 3

May be its an issue with file encoding. Though I am not sure. Can you please try following piece of code and see if it works for you

BufferedReader in = new BufferedReader(
new InputStreamReader( new FileInputStream("output.txt"), "UTF8"));

String str;

while ((str = in.readLine()) != null) {
  System.out.println(str);
}