package xyz.zhouxy.plusone.commons.util; import java.util.Arrays; public class StrUtil { public static String fillBefore(String src, int minLength, char c) { if (src.length() >= minLength) { return src; } char[] result = new char[minLength]; Arrays.fill(result, 0, minLength - src.length(), c); for (int i = 1; i <= src.length(); i++) { result[minLength - i] = src.charAt(src.length() - i); } return String.valueOf(result); } public static String fillAfter(String src, int minLength, char c) { if (src.length() >= minLength) { return src; } char[] result = new char[minLength]; for (int i = 0; i < src.length(); i++) { result[i] = src.charAt(i); } Arrays.fill(result, src.length(), result.length, c); return String.valueOf(result); } private StrUtil() { throw new IllegalStateException("Utility class"); } }