Count.java

import java.util.List;
import java.util.Arrays;

class Count {

  public static void main(String[] args) {
    List<String> test = Arrays.asList(new String[]{"0", "1", "2"});    
    count(test, 3);
	}
  
  /**
  * prints all possible permutations of "s" in incremental order
  * @param s ordered list of elements (incremental order)
  * @param l of the permutations
  */
  public static void count(List<String> s, int l) {
    int[] counter = new int[l];
    int n = s.size();        
    
    OUTER:
    while(true) {    
      print(s, counter);
      
      for (int i = l - 1; ++counter[i] == n; counter[i--] = 0) {
        if (i == 0) {
          break OUTER; 
        }
      }       
    }
    
    System.out.println("DONE");    
  }
  
  public static void print(List<String> s, int[] counter) {
    //build output
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < counter.length; i++) {
      sb.append(s.get(counter[i]));
    }
    sb.append(System.lineSeparator());
    
    System.out.println(sb);
    
    try {
      Thread.sleep(200);
    } catch (Exception e) {}
  }
}