How to substring a given string with specific rules in java

Question

This is my code and it is showing error at while.Index out of bound exception is coming.The substrings should be such that

1. Max 50 characters per string
2. No number should be broken - for example " 4318, 4466, 486," is acceptable but " 4318, 4466, 48" is not
3. Substring should always start with one space and end with comma ","

can someone help me out with this please

 public class MyString {

/**
 * @param args

 */
static String input = " 4318, 4466, 486, 1698, 478, 590, 582, 1594, 486, 1690, 702, 378, 486, 586, 486, 1694, 486, 598, 538, 526, 486, 1694, 486, 622, 434, 630, 462, 1730, 422, 1754, 450, 586, 486, 1690, 498, 1682, 486, 586, 502, 606, 454, 1698, 478, 1694, 486, 1718, 458, 1686, 726, 1458, 646, 426, 486, 1694, 482, 1694, 486, 590, 482, 622, 490, 550, 490, 602, 450, 634, 466, 586, 486, 1730, 426, 1714, 494, 622, 446, 590, 494, 618, 450, 586, 490, 586, 486, 1730, 450, 586, 486, 590, 502, 1674, 530, 1650, 482, 1690, 558, 1622, 486, 1690, 486, 5298, 4306, 4466, 530, 1646, 486, 594, 650, 1502, 546, 1650, 490, 586, 486, 622, 522, 1622, 486, 602, 454, 634, 462, 1694, 482, 590, 486, 590, 486, 1694, 482, 1730, 450, 590, 498, 1638, 526, 1690, 498, 606, 458, 586, 486, 1698, 482, 1694, 482, 1690, 486, 1694, 486, 1698, 574, 494, 486, 1714, 462, 1690, 486, 626, 430, 610, 486, 590, 490, 622, 426, 610, 498, 618, 446, 1690, 486, 1734, 446, 590, 482, 590, 502, 606, 454, 590, 502, 582, 478, 1690, 486, 586, 506, 578, 482, 1686, 558, 1622, 674, 1506, 482, 1698, 590, 1606, 462, 1000";
char space=' ';
 static char comma=',';
public static void main(String[] args) {
    // TODO Auto-generated method stub
    int start=0, end=0;
    while (end-1 < input.length()){

    start=end;
    end= start+ 50;

    String output= input.substring(start,end);
    if(output.charAt(start)==' ' && output.charAt(end-1)==',')
    {
    System.out.println(output);
    } 
    else 
    {

    while(!(output.charAt(end-1)==','))
    {

    end--;

    }
    output= input.substring(start,end);
    System.out.println(output);

    }
    }
    }



}

Answer 1

I have made slight modification in your code.

class Ideone {

static String input = " 4318, 4466, 486, 1698, 478, 590, 582, 1594, 486, 1690, 702, 378, 486, 586, 486, 1694, 486, 598, 538, 526, 486, 1694, 486, 622, 434, 630, 462, 1730, 422, 1754, 450, 586, 486, 1690, 498, 1682, 486, 586, 502, 606, 454, 1698, 478, 1694, 486, 1718, 458, 1686, 726, 1458, 646, 426, 486, 1694, 482, 1694, 486, 590, 482, 622, 490, 550, 490, 602, 450, 634, 466, 586, 486, 1730, 426, 1714, 494, 622, 446, 590, 494, 618, 450, 586, 490, 586, 486, 1730, 450, 586, 486, 590, 502, 1674, 530, 1650, 482, 1690, 558, 1622, 486, 1690, 486, 5298, 4306, 4466, 530, 1646, 486, 594, 650, 1502, 546, 1650, 490, 586, 486, 622, 522, 1622, 486, 602, 454, 634, 462, 1694, 482, 590, 486, 590, 486, 1694, 482, 1730, 450, 590, 498, 1638, 526, 1690, 498, 606, 458, 586, 486, 1698, 482, 1694, 482, 1690, 486, 1694, 486, 1698, 574, 494, 486, 1714, 462, 1690, 486, 626, 430, 610, 486, 590, 490, 622, 426, 610, 498, 618, 446, 1690, 486, 1734, 446, 590, 482, 590, 502, 606, 454, 590, 502, 582, 478, 1690, 486, 586, 506, 578, 482, 1686, 558, 1622, 674, 1506, 482, 1698, 590, 1606, 462, 1000";
char space = ' ';
static char comma = ',';

public static void main(String[] args) {
    // TODO Auto-generated method stub
    int start = 0, end = 0;
    int temp = 0;
    while (end < input.length()) {

        start = end;
        end = Math.min(start + 50, input.length());

        String output = input.substring(start, end - 1);
        if (output.charAt(0) == ' ' && output.charAt(output.length() - 1) == ',') {
            System.out.println(output);
            end--;
        } else {
            temp = output.length() - 1;
            while (temp!=-1 && output.charAt(temp) != ',') {
                temp--;
            }
            if(temp==-1)break;
            output = input.substring(start, start + temp + 1);
            System.out.println(output);
            end = start + temp + 1;
        }

    }
}
}

Demo