CodeEval Challenge: Remove specified characters from a string

Question


Write a program which removes specific characters from a string.

The first argument is a path to a file. The file contains the source
strings and the characters that need to be scrubbed. Each source
string and characters you need to scrub are delimited by comma.

Input sample:


how are you, abc

hello world, def

Output sample:


how re you

hllo worl

I have used regex to eliminate the characters.

public class Main{

    public static void main(String[] args) throws IOException {
        File file = new File(args[0]);
        BufferedReader br = new BufferedReader(new FileReader(file));           
            String s;
            while ((s = br.readLine()) != null) {
                s = s.trim();
                String arr[]=s.split(",\\s");
                String pat="([^"+arr[1]+"])";
                Pattern p=Pattern.compile(pat);
                Matcher m=p.matcher(arr[0]);
                while(m.find())
                {
                    System.out.print(m.group(0));
                }
                System.out.println();
            }
            br.close();
        }

    }

The above code passes all the test cases.

Is this the most optimized code or can it be improved further?

You can extract out the requirement into its own method:

private static String removeCharacters(String input, String excludedLetters) {
    // ...
}

And since you have to split from a single String first, you can use a wrapper method in addition to the one above:

private static String removeCharacters(String line) {
    String[] parts = // ...
    return removeCharacters(parts[0], parts[1]);
}

If you are on Java 8, you can use a combination of try-with-resources and Files.lines() to Streamline the processing (pun intended):

try (Stream lines = Files.lines(Paths.get(/* ... */))) {
    lines.map(Main::removeCharacters).forEach(System.out::println);
}

StackExchange Code Review Q#98323, answer score: 4