import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegexReplace
{
public static void main(String args[])
{
Pattern str_pattern = Pattern.compile("(java) (et)");
StringBuffer sb = new StringBuffer();
String texte = "J'aime java et perl";
String replacement = "$1 Python $2";
Matcher matcher = str_pattern.matcher(texte);
if(matcher.find())
{
matcher.appendReplacement(sb, replacement);
String msg = sb.toString();
System.out.println(msg);
}
}
}