java replaceLast() [duplicate]

Answer 1

split the haystack by your needle using a lookahead regex and replace the last element of the array, then join them back together :D

String haystack = "haystack haystack haystack";
String lookFor = "hay";
String replaceWith = "wood";

String[] matches = haystack.split("(?=" + lookFor + ")");
matches[matches.length - 1] = matches[matches.length - 1].replace(lookFor, replaceWith);
String brandNew = StringUtils.join(matches);

Answer 2

If the inspected string is so that

myString.endsWith(substringToReplace) == true

you also can do

myString=myString.replaceFirst("(.*)"+myEnd+"$","$1"+replacement) 

Answer 3

You can combine StringUtils.reverse() with String.replaceFirst()

Answer 4

use replaceAll and add a dollar sign right after your pattern:

replaceAll("pattern$", replacement);

Answer 5

No.

You could do reverse / replaceFirst / reverse, but it's a bit expensive.

Answer 6

it is slow, but works:3

    import org.apache.commons.lang.StringUtils;

public static String replaceLast(String str, String oldValue, String newValue) {
    str = StringUtils.reverse(str);
    str = str.replaceFirst(StringUtils.reverse(oldValue), StringUtils.reverse(newValue));
    str = StringUtils.reverse(str);
    return str;
}