Java replace matched regex [duplicate]

Question

This question already has an answer here:

Java replace Matcher (1 answer)

Closed 8 years ago.

Sorry i had to re write this question i was in the middle of finishing it and someone closed it. they weren't kind enough to explain why so i had to repost? please inform me what is confusing.

Main point: I want to replace a regex match with part of the match so if i regex hi i want it to be replaced with {hi} if regex match at i want to replace with {at}

this is awesome look at this two letter words get replaced the return would be

this <h1>is</h1> awesome look <h1>at</h1> this two letter words get replaced

notice how the is and at which would match regex \b\w\w\b would be matched a replaced

this is the code i was working on... don't judge it's not finished but i am just a little confused and wondering if there is an easier way. i was search the string and finding the matches and then i was going to go it to an arraylist and replace each one. The problem is one of the thing that i am replacing is { and i want to replace it with {{} now in a look this will continually replace the brackets because i keep adding them... so my other thought was to replace them all one by one char by char and add to a new StringBuilder object?

ArrayList<String> replacements= new ArrayList<String>();
String s="::";
s+=command;
Pattern p= Pattern.compile("[!-~]");
Matcher match= p.matcher(this.execution);
while(match.find()){
    replacements.add(match.group());
}
StringBuilder string= new StringBuilder();
for(int i=0;i<this.execution.length();i++){ 
    String a=new String(execution.charAt(i));
    if(...){
        ...
    }
}
s+="::"+this.execution;

Answer 1

try

str = str.replaceAll("(\\b\\w\\w\\b)", "<h1>$1</h1>");