Javaでシーケンス法で全配列を生成する

import java.io.*;
import java.util.ArrayList;

class Arrangement{
	
	public static void main(String args[]){
		Arrangement arrangement = null;
		int num = 0;//      
		boolean flag = true;//   ，               ，     true
		ArrayList<String> strs = new ArrayList<String>();
		while(flag){
			try{
		   		num = Integer.parseInt(readDataFromConsole("         ："));
				flag = false;
			}catch(Exception e){
				System.out.println("     .");
			}
		}
		for(int i = 1; i <= num; i ++){
			strs.add(readDataFromConsole("    " + i + "   : ")); 
		}
		arrangement = new Arrangement(strs.toArray(new String[]{}));
		System.out.println("       ：");
		arrangement.sort();
	}
	
	private String[] str = null;
	
	public Arrangement(String[] s){
		this.str = s;
	}
	//        
	private static String readDataFromConsole(String prompt) {
        	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        	String str = null;
        	try {
            		System.out.print(prompt);
            		str = br.readLine();

        	} catch (IOException e) {
            		e.printStackTrace();
        	}
        	return str;
    	}
	
	private void sort(){
		int num=str.length;
		
		int[] n1 = new int[num -1];
		int[] nss = new int[num];
		String[] s = new String[num];
		
		boolean flag = false;
		int x = 0;
		
		do{
			if(x == 0){//      
				for(int i = 0;i < num - 1;i ++){
					n1[i] = 0;
 				}
			} else {//    
				for(int i = 0;i < num - 1;i ++){
					if(n1[num - 2 - i] < i + 1){
						n1[num - 2 - i] ++;
						for(int j=num-1-i;j<num-1;j++){
							n1[j] = 0;
						}
						break;
					}
				}
			}
			for(int i = 0;i < num - 1;i++){
				if(n1[i] == (num - 1 - i)){
					flag = false;
				} else {
					flag = true;
					break;
				}
			}
			for(int i = 0;i < num;i++){//      
				nss[i] = 0;
			}
			for(int i = 0;i < num - 1;i++){//              
				int hh = 0, j = 0;//           
				do{
					if(nss[num - 1 - hh] == 1){
						hh++;
						continue;
					} else {
						if(j == n1[i]){
							break;//              
						} else {
							hh++;
							j++;
						}
					}
				} while(true);
				hh = num - 1 - hh;
				s[hh] = str[num-1-i];
				nss[hh] = 1;
			}
			for(int i = 0; i < num;i++){//     
				if(nss[i] == 0) {
					s[i] = str[0];
					break;
				}
			}
			System.out.print(++x + "\t");
			for(int i = 0;i < num - 1;i++){
				System.out.print(n1[i] + "");
			}
			System.out.print("\t");
			for(int i = 0;i < num;i++){
				System.out.print(s[i] + "");
			}
			System.out.println();
		}while(flag);
	}
}