拉长题目

<%@tag description="fixed width text" pageEncoding="UTF-8" trimDirectiveWhitespaces="true" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@attribute name="text" required="true" rtexprvalue="true" type="java.lang.String"%>
<%@attribute name="widthInEm" required="true" rtexprvalue="true" type="java.lang.Float"%>
<%
    String text = (String)jspContext.getAttribute("text");
    Float widthInEm = (Float)jspContext.getAttribute("widthInEm");
    String result = HtmlTagUtils.toFixedWidth(text, widthInEm);
    jspContext.setAttribute("result", result);
%>
${result}

<%@ taglib tagdir="/WEB-INF/tags" prefix="t"%>
<t:fixedWidth text="${user.realName}" widthInEm="3" />

public class HtmlTagUtils {
    public static String toFixedWidth(String text, Float widthInEm) {
        String result = text;
        if (widthInEm != null && text.length() < widthInEm && text.length() > 1) {
            Float space = (widthInEm - text.length()) / (text.length() - 1);
            Character[] characters = toCharacters(text);
            List list = (List) Arrays.asList(characters);
            result =   join(list, "<span style='display: inline-block; zoom: 1; width:" + space + "em'></span>");
        }
        return result;
    }
    public static String join(Iterable pColl, String separator) {
        Iterator oIter;
        if (pColl == null || (!(oIter = pColl.iterator()).hasNext())) {
            return "";
        }
        StringBuilder oBuilder = new StringBuilder(String.valueOf(oIter.next()));
        while (oIter.hasNext()) {
            oBuilder.append(separator).append(oIter.next());
        }
        return oBuilder.toString();
    }
    public static Character[] toCharacters(String str) {
        char[] chars = str.toCharArray();
        Character[] result = new Character[chars.length];
        for (int i = 0; i < chars.length; i++) {
            result[i] = chars[i];
        }
        return result;
    }
}