This is a recursive approach for permutation output.

RecursivePermutation.java

package com.berkanaslan;

import java.util.Scanner;

public class RecursivePermutation {
    public static void main(String[] args) {
        final String input = getInput();
        final String output = "";

        permute(input, output);
        System.out.println(output);
    }

    private static String getInput() {
        final Scanner scanner = new Scanner(System.in);
        System.out.println("Provide input: ");
        return scanner.nextLine();
    }

    private static void permute(String input, String output) {
        if (input.length() == 0) {
            System.out.println(output);
            return;
        }

        for (int i = 0; i < input.length(); i++) {
            final char c = input.charAt(i);

            final String leftCharsOfC = input.substring(0, i);
            final String rightCharsOfC = input.substring(i + 1);
            final String restOfTheInput = leftCharsOfC + rightCharsOfC;

            permute(restOfTheInput, output + c);
        }
    }
}