QuoteReplacement
The replacement string can contain references to the groups in the pattern: $n is replaced with the nth group, and ${name} is replaced with the group that has the given name. Use \\$ to include a $ character in the replacement text.
If you have a string that may contain $ and \, and you don’t want them to be interpreted as group replacements, call matcher.replaceAll(Matcher.quoteReplacement(String str)).
Program
import java.util.regex.Pattern; import java.util.regex.Matcher; public class Javaapp { public static void main(String[] args) { Pattern pat = Pattern.compile("AAA(BBB)(CCC)"); Matcher mat = pat.matcher("AAABBBCCCXXX"); String str = mat.replaceAll(Matcher.quoteReplacement("$1 Android $2")); System.out.println(str); } }