给出一个数字n,求出所有的全排列

给出一个数字n,求出所有的全排列，如给出３则结果为：
3210
2310
2130
2103
3120
1320
1230
1203
3102
1302
1032
1023
3201
2301
2031
2013
3021
0321
0231
0213
3012
0312
0132
0123
代码如下：

import java.util.*;
import java.io.*;
public class P1 {
	public static void main( String[] args  ); {
		try {
			BufferedReader in = new BufferedReader( new InputStreamReader( System.in ); );;
			System.out.println("Enter the number:");;
			String input = in.readLine();;
			int inputInt = Integer.parseInt( input );;
			P1 p = new P1();;
			LinkedList< String > a = new LinkedList< String >();;
			while( inputInt != -1 ); {
				a = p.convert( inputInt );;
				System.out.println("The Result is:");;
				for( int i = 0;i < a.size();;i++ ); {
					System.out.println( a.get( i ););;
				}
				System.out.println("contain " + a.size(); + " numbers!" );;
				System.out.println("Enter the number:");;
				input = in.readLine();;
				inputInt = Integer.parseInt( input );;
			}
		}catch( Exception e ); {
			e.printStackTrace();;
		}
	}
	public LinkedList<String> convert( int n ); {
		LinkedList< String > temp = new LinkedList< String >();;
		LinkedList< String > result = new LinkedList< String >();;
		if( n == 0 ); {
			result.add( "0" );;
			return result;
		}
		if( n < 0 ); {
			System.out.println("error!!");;
			return temp;
		}
		temp = convert( n - 1 );;
		String tempStr = new String();;
		StringBuffer tempSB = new StringBuffer();;

		for( int i = 0;i < temp.size();;i++ );  {
			tempStr = temp.get( i );;
			//System.out.println( "TEST1:" + tempStr );;
			tempSB = new StringBuffer( tempStr );;
			for(int j = 0;j < n + 1;j++ ); {
				tempStr = new String( tempSB.insert(j,n); );;
				result.add( tempStr );;
				tempSB.deleteCharAt( j );;
				//System.out.println( "TEST2:" + tempStr );;
			}
		}
		return result;
	}
}