CODEWITHSUNDEEP
java
boycod3
boycod3

Reputation: 5317

split string by fixed length and fill the free spaces with white spaces

I want to split strings into fixed-length, for example, split by 20 characters and if after splitting length is less than 20 characters, then fill the string with whitespace up to 20 characters.

public static List<String> splitEqually(String text, int size) {

    List<String> ret = new ArrayList<String>((text.length() + size - 1) / size);

    for (int start = 0; start < text.length(); start += size) {
        ret.add(text.substring(start, Math.min(text.length(), start + size)));
    }
    return ret;
}

I used the above code to split by equal size.

Upvotes: 0

Views: 844

Answers (3)

Kaplan
Kaplan

Reputation: 3728

with lambda

String blanks20 = "                    ";
ArrayList<String> fixed20 = list.stream().collect( Collector.of( ArrayList::new,
    (l, s) -> {
        for(int i = 0; ; s = s.substring( 20 )) {
          l.add( (s + blanks20).substring( i, i + 20 ) );
          if( s.length() < 20 )
            break;
        } },
      (l, r) -> { l.addAll( r ); return( l ); } ) );

Upvotes: 0

Andreas
Andreas

Reputation: 159106

Only the last value might not be of the given size, so pad it with spaces if needed, after the loop.

public static List<String> splitFixedWidth(String text, int width) {
    List<String> ret = new ArrayList<>((text.length() + width - 1) / width);
    for (int start = 0; start < text.length(); start += width) {
        ret.add(text.substring(start, Math.min(text.length(), start + width)));
    }
    if (! ret.isEmpty()) {
        String lastValue = ret.get(ret.size() - 1);
        if (lastValue.length() < width) {
            lastValue += " ".repeat(width - lastValue.length());
            ret.set(ret.size() - 1, lastValue);
        }
    }
    return ret;
}

In Java versions below 11, use:

        if (lastValue.length() < width) {
            char[] buf = new char[width];
            lastValue.getChars(0, lastValue.length(), buf, 0);
            Arrays.fill(buf, lastValue.length(), width, ' ');
            ret.set(ret.size() - 1, new String(buf));
        }

Or shorter but less efficient:

        if (lastValue.length() < width) {
            ret.set(ret.size() - 1, String.format("%-" + width + "s", lastValue));
        }

Upvotes: 2

Sarangan
Sarangan

Reputation: 967

This code will resolve your problem. 

public static List<String> splitEqually(String text, int size) {

    List<String> ret = new ArrayList<String>((text.length() + size - 1) / size);
    StringBuilder str1 = new StringBuilder();
    for (int start = 0; start < text.length(); start += size) {
        String temp = text.substring(start, Math.min(text.length(), start + size));
        if (temp.length() == size) {
            ret.add(temp);
            System.out.println(temp.length());
        } else {
            int n = size - temp.length();
            str1.append(temp);
            for (int j =0 ; j< n ; j++){
                str1.append(" ");
            }
            System.out.println(str1.length());
            ret.add(str1.toString());
        }

    }
    return ret;
}

Upvotes: 3

Related Questions