Try something like this:
public void tagToCamelCase(String input){
char[] inputArray = input.toCharArray();
for (int i = 0; i < inputArray.length-2; i++){
if (inputArray[i] == '<'){
if(inputArray[i+1]!= "https://stackoverflow.com/")
inputArray[i+1] = Character.toLowerCase(inputArray[i+1]);
else
inputArray[i+2] = Character.toLowerCase(inputArray[i+2]);
}
}
System.out.println(new String(inputArray));
}
Note: the tag ID will be iD and not id. Hope this helps.