Java String Pad Left leftPad(String s, int minLength)

Description

Pads the string at the left with spaces until it reaches the desired length.

License

Open Source License

Parameter

Parameter	Description
s	the string that will be padded.
minLength	the length to reach.

Declaration

public static String leftPad(String s, int minLength) 

Method Source Code

//package com.java2s;

public class Main {
    /**/*w w w.java2s  . c  om*/
     * Pads the string at the left with spaces until it reaches the desired
     * length. If the string is longer than this length, then it returns the
     * unchanged string. 
     * 
     * @param s the string that will be padded.
     * @param minLength the length to reach.
     */
    public static String leftPad(String s, int minLength) {
        return leftPad(s, minLength, ' ');
    }

    /**
     * Pads the string at the left with the specified character until it reaches
     * the desired length. If the string is longer than this length, then it
     * returns the unchanged string.
     * 
     * @param s the string that will be padded.
     * @param minLength the length to reach.
     * @param filling the filling pattern.
     */
    public static String leftPad(String s, int minLength, char filling) {
        int ln = s.length();
        if (minLength <= ln) {
            return s;
        }

        StringBuffer res = new StringBuffer(minLength);

        int dif = minLength - ln;
        for (int i = 0; i < dif; i++) {
            res.append(filling);
        }

        res.append(s);

        return res.toString();
    }

    /**
     * Pads the string at the left with a filling pattern until it reaches the
     * desired length. If the string is longer than this length, then it returns
     * the unchanged string. For example: <code>leftPad('ABC', 9, '1234')</code>
     * returns <code>"123412ABC"</code>.
     * 
     * @param s the string that will be padded.
     * @param minLength the length to reach.
     * @param filling the filling pattern. Must be at least 1 characters long.
     *     Can't be <code>null</code>.
     */
    public static String leftPad(String s, int minLength, String filling) {
        int ln = s.length();
        if (minLength <= ln) {
            return s;
        }

        StringBuffer res = new StringBuffer(minLength);

        int dif = minLength - ln;
        int fln = filling.length();
        if (fln == 0) {
            throw new IllegalArgumentException("The \"filling\" argument can't be 0 length string.");
        }
        int cnt = dif / fln;
        for (int i = 0; i < cnt; i++) {
            res.append(filling);
        }
        cnt = dif % fln;
        for (int i = 0; i < cnt; i++) {
            res.append(filling.charAt(i));
        }

        res.append(s);

        return res.toString();
    }
}

Related

1. leftPad(String s, char paddingCharacter, int length)
2. leftPad(String s, int l)
3. leftPad(String s, int len, char c)
4. leftPad(String s, int length)
5. leftPad(String s, int length)
6. leftPad(String s, int n)
7. leftPad(String s, int target)
8. leftPad(String s, int width)
9. leftPad(String s, int z)