null error problem

I'm not good at all with reading and writing files. My problem is that I always get a null error. How would I fix this?

Code:

public void addOps(){
        try{
            // Open the file that is the first
            // command line parameter
            FileInputStream fstream = new FileInputStream("ops.txt");

            // Get the object of DataInputStream
            DataInputStream in = new DataInputStream(fstream);
            BufferedReader br = new BufferedReader(new InputStreamReader(in));
            String strLine;

            //Read File Line By Line
            while ((strLine = br.readLine().toLowerCase(Locale.ENGLISH).trim()) != null){
                plugin.gameOps.add(strLine);
            }
            //Close the input stream
            in.close();
        }
        catch (Exception e){
            System.err.println("Error: ~" + e.getMessage());
        }
    }

 

Code:

        File file;
        file = new File("plugins/pluginName", "FileName.ext");
        Scanner scan;
        try {
            if (!file.exists())
                file.createNewFile();
            scan = new Scanner(file);
            while (scan.hasNextLine()) {
                String line = scan.nextLine();
                if (!line.contains("="))
                    continue;
                if (line.length() == 0)
                    continue;
                if (line.trim().charAt(0) == '#')
                    continue;
                int equals = line.indexOf("=");
                int commentIndex = line.length();
                String key = line.substring(0, equals).trim();
                if (key.equals(""))
                    continue;
                String value = line.substring(equals + 1, commentIndex).trim();
            }

        } catch (IOException e) {
            }

This is my file reading code, don't know if it helps.

 

the problem is I get a null error even though my code checks to prevent it...

 

"Null error" isn't very helpful. State the line relevant to your paste in which it's crapping itself.

 

it was the while line.

 

You have to convert the line to lower case and trim it inside the while loop

Code:

while ((strLine = br.readLine()) != null){
   strLine = strLine .toLowerCase(Locale.ENGLISH).trim();
   plugin.gameOps.add(strLine);
}

 

that would make total sense!.... now I feel so stupid.