Java String Truncate truncateNicely(String str, int lower, int upper, String appendToEnd)

Description

This method based on code from the String taglib at Apache Jakarta.

License

Apache License

Declaration

public static String truncateNicely(String str, int lower, int upper, String appendToEnd) 

Method Source Code

//package com.java2s;

public class Main {
    /**//from   w w  w  .  ja v a  2  s.c  o m
     * This method based on code from the String taglib at Apache Jakarta.
     * http://cvs.apache.org/viewcvs/jakarta-taglibs/string/src/org/apache/taglibs/string/util/StringW.java?rev=1.16&content-type=text/vnd.viewcvs-markup
     * Copyright (c) 1999 The Apache Software Foundation.
     * Author: Henri Yandell bayard@generationjava.com
     */
    public static String truncateNicely(String str, int lower, int upper, String appendToEnd) {

        // strip markup from the string
        String str2 = removeHTML(str, false);
        boolean diff = (str2.length() < str.length());

        // quickly adjust the upper if it is set lower than 'lower'
        if (upper < lower) {
            upper = lower;
        }

        // now determine if the string fits within the upper limit
        // if it does, go straight to return, do not pass 'go' and collect $200
        if (str2.length() > upper) {
            // the magic location int
            int loc;

            // first we determine where the next space appears after lower
            loc = str2.lastIndexOf(' ', upper);

            // now we'll see if the location is greater than the lower limit
            if (loc >= lower) {
                // yes it was, so we'll cut it off here
                str2 = str2.substring(0, loc);
            } else {
                // no it wasnt, so we'll cut it off at the upper limit
                str2 = str2.substring(0, upper);
                loc = upper;
            }

            // HTML was removed from original str
            if (diff) {

                // location of last space in truncated string
                loc = str2.lastIndexOf(' ', loc);

                // get last "word" in truncated string (add 1 to loc to eliminate space
                String str3 = str2.substring(loc + 1);

                // find this fragment in original str, from 'loc' position
                loc = str.indexOf(str3, loc) + str3.length();

                // get truncated string from original str, given new 'loc'
                str2 = str.substring(0, loc);

                // get all the HTML from original str after loc
                str3 = extractHTML(str.substring(loc));

                // remove any tags which generate visible HTML
                // This call is unecessary, all HTML has already been stripped
                //str3 = removeVisibleHTMLTags(str3);

                // append the appendToEnd String and
                // add extracted HTML back onto truncated string
                str = str2 + appendToEnd + str3;
            } else {
                // the string was truncated, so we append the appendToEnd String
                str = str2 + appendToEnd;
            }

        }

        return str;
    }

    /**
     * Remove occurences of html, defined as any text
     * between the characters "&lt;" and "&gt;".
     * Optionally replace HTML tags with a space.
     */
    public static String removeHTML(String str, boolean addSpace) {

        if (str == null)
            return "";
        StringBuffer ret = new StringBuffer(str.length());
        int start = 0;
        int beginTag = str.indexOf("<");
        int endTag = 0;
        if (beginTag == -1)
            return str;

        while (beginTag >= start) {
            if (beginTag > 0) {
                ret.append(str.substring(start, beginTag));

                // replace each tag with a space (looks better)
                if (addSpace)
                    ret.append(" ");
            }
            endTag = str.indexOf(">", beginTag);

            // if endTag found move "cursor" forward
            if (endTag > -1) {
                start = endTag + 1;
                beginTag = str.indexOf("<", start);
            }
            // if no endTag found, get rest of str and break
            else {
                ret.append(str.substring(beginTag));
                break;
            }
        }
        // append everything after the last endTag
        if (endTag > -1 && endTag + 1 < str.length()) {
            ret.append(str.substring(endTag + 1));
        }
        return ret.toString().trim();
    }

    /**
     * Remove occurences of html, defined as any text
     * between the characters "&lt;" and "&gt;".  Replace
     * any HTML tags with a space.
     */
    public static String removeHTML(String str) {
        return removeHTML(str, true);
    }

    /**
      * Extract (keep) JUST the HTML from the String.
      * @param str
      * @return
      */
    public static String extractHTML(String str) {
        if (str == null)
            return "";
        StringBuffer ret = new StringBuffer(str.length());
        int start = 0;
        int beginTag = str.indexOf("<");
        int endTag = 0;
        if (beginTag == -1)
            return str;

        while (beginTag >= start) {
            endTag = str.indexOf(">", beginTag);

            // if endTag found, keep tag
            if (endTag > -1) {
                ret.append(str.substring(beginTag, endTag + 1));

                // move start forward and find another tag
                start = endTag + 1;
                beginTag = str.indexOf("<", start);
            }
            // if no endTag found, break
            else {
                break;
            }
        }
        return ret.toString();
    }
}

Related

1. truncateMessage(String message, int TRUNCATED_MSG_SIZE)
2. truncateMessageIn50000Characters(final String message)
3. truncateName(String name)
4. truncateName(String name)
5. truncateNicely(String s, int n, String suffix)
6. truncateNumberSign(String s)
7. truncateOnlyText(String text, int position)
8. truncateOnSpace(String text, Integer length)
9. truncateOrPadString(String str)