Java Replacing multiple different substring in a s

Question

I need to replace many different sub-string in a string in the most efficient way. is there another way other then the brute force way of replacing each field using string.replace ?

Answer 1

Rythm a java template engine now released with an new feature called String interpolation mode which allows you do something like:

String result = Rythm.render("@name is inviting you", "Diana");

The above case shows you can pass argument to template by position. Rythm also allows you to pass arguments by name:

Map<String, Object> args = new HashMap<String, Object>();
args.put("title", "Mr.");
args.put("name", "John");
String result = Rythm.render("Hello @title @name", args);

Note Rythm is VERY FAST, about 2 to 3 times faster than String.format and velocity, because it compiles the template into java byte code, the runtime performance is very close to concatentation with StringBuilder.

Links:

• Check the full featured demonstration
• read a brief introduction to Rythm
• download the latest package or
• fork it

Answer 2

How about using the replaceAll() method?

Answer 3

public String replace(String input, Map<String, String> pairs) {
  // Reverse lexic-order of keys is good enough for most cases,
  // as it puts longer words before their prefixes ("tool" before "too").
  // However, there are corner cases, which this algorithm doesn't handle
  // no matter what order of keys you choose, eg. it fails to match "edit"
  // before "bed" in "..bedit.." because "bed" appears first in the input,
  // but "edit" may be the desired longer match. Depends which you prefer.
  final Map<String, String> sorted = 
      new TreeMap<String, String>(Collections.reverseOrder());
  sorted.putAll(pairs);
  final String[] keys = sorted.keySet().toArray(new String[sorted.size()]);
  final String[] vals = sorted.values().toArray(new String[sorted.size()]);
  final int lo = 0, hi = input.length();
  final StringBuilder result = new StringBuilder();
  int s = lo;
  for (int i = s; i < hi; i++) {
    for (int p = 0; p < keys.length; p++) {
      if (input.regionMatches(i, keys[p], 0, keys[p].length())) {
        /* TODO: check for "edit", if this is "bed" in "..bedit.." case,
         * i.e. look ahead for all prioritized/longer keys starting within
         * the current match region; iff found, then ignore match ("bed")
         * and continue search (find "edit" later), else handle match. */
        // if (better-match-overlaps-right-ahead)
        //   continue;
        result.append(input, s, i).append(vals[p]);
        i += keys[p].length();
        s = i--;
      }
    }
  }
  if (s == lo) // no matches? no changes!
    return input;
  return result.append(input, s, hi).toString();
}

Answer 4

Check this:

String.format(str,STR[])

...

For example:

String.format( "Put your %s where your %s is", "money", "mouth" );