错误ArrayIndexOutOfBounds异常

Question

我的矩阵代码在多行中给出以下错误，我无法理解为什么。我会欢迎任何帮助。我一直有错误，数组索引越界异常。我的方法有什么问题或者我怎么能抓住这个例外？

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 3
    at mb.Mb.swap(Mb.java:65)
    at mb.Mb.randomiseRow(Mb.java:56)
    at mb.Mb.main(Mb.java:121)

以下是我的代码：

package mb;

import java.util.*;
public class Mb {

    /**
     * @param args the command line arguments
     */

    public static int[][] createMatrix(int size) 
    {
        int[][] boardMatrix = new int[size][size];
        return boardMatrix;
    }

    public static void print(int[][] board)
    {
        for(int i = 0; i<board.length; i++)
        {
            for(int j = 0; j<board[i].length; j++)
            {
                System.out.print(board[i][j] + " ");
            }
            System.out.println();
        }
    }


    public static int[] singleRow(int size, int startValue)
    {
        int[] row = new int[size];
        for(int i = 0; i<row.length; i++)
        {
            row[i] = i + startValue;
        }
        return row;
    }

     public static void randomiseRow(int[] board)
    {
        Random rnd = new Random();
        int randX = 0;
        int randY = 0;

        for(int x = 0; x<board.length; x++) //no of rows
        {
                swap(board, x, (rnd.nextInt(board.length)+1));

            }
        }


    public static void swap(int[] board, int a, int b)
    {
        int temp = board[a];
        board[a] = board[b];
        board[b] = temp;

    }

    public static boolean compareArray(int[] board1, int[] board2)
    {
        if(board1.length != board2.length)
        {
            return false;
        }
        for(int i = 0; i<board1.length; i++)
        {
            if(board1[i] == board2[i])
            {
                return false;
            }
        }
        return true;
    }

    public static boolean compare2DArray(int[] board1, int[][] board2, int startValue, int endValue)
    {
        for(int i = startValue; i<endValue; i++)
        {
            if(!compareArray(board1, board2[i]))
            {
                return false;
            }
        }
        return true;
    }


    public static void main(String[] args) {
        // TODO code application logic here

        int userInput = 0;


        System.out.print("Matrix size: ");
        Scanner scn = new Scanner(System.in);
        userInput = scn.nextInt();
        while(userInput < 0 && userInput > 9)
        {
            System.out.println("Invalid matrix size. Re-enter ");
            userInput = scn.nextInt();

        }

        int[][] matrixBoard = new int[userInput][userInput];
        createMatrix(userInput);
        for(int i = 1; i<userInput; i++)
        {
            matrixBoard[0] = singleRow(userInput, 1);
            do{
                randomiseRow(matrixBoard[i]);
            }while(!compare2DArray(matrixBoard[i], matrixBoard, 0, i));
        }

        print(matrixBoard);
    }

}