public void run() { // each file is processed into a local hash table and then merged with the global results // this will cause much less contention on the global table, but still avoids a sequential // update Hashtable<String, Integer> local_results = new Hashtable<String, Integer>(WordCountJ.HASH_SIZE, WordCountJ.LF); // grab a file to work on String cf; while ((cf = files.poll()) != null) { try { BufferedReader input = new BufferedReader(new FileReader(cf)); String text; // well go line-by-line... maybe this is not the fastest while ((text = input.readLine()) != null) { // parse words Matcher matcher = pattern.matcher(text); while (matcher.find()) { String word = matcher.group(1); if (local_results.containsKey(word)) { local_results.put(word, 1 + local_results.get(word)); } else { local_results.put(word, 1); } } } input.close(); } catch (Exception e) { System.out.println(" caught a " + e.getClass() + "\n with message: " + e.getMessage()); return; } // merge local hashmap with shared one,could have a // seperate thread do this but that might be cheating Iterator<Map.Entry<String, Integer>> updates = local_results.entrySet().iterator(); while (updates.hasNext()) { Map.Entry<String, Integer> kv = updates.next(); String k = kv.getKey(); Integer v = kv.getValue(); synchronized (results) { if (results.containsKey(k)) { results.put(k, v + results.get(k)); } else { results.put(k, v); } } } local_results.clear(); } }
public String getLegend(String[] cityMap, int[] POIs) { char[] ans = new char[POIs.length]; Hashtable hash = new Hashtable(); for (int i = 0; i < cityMap.length; i++) { for (int j = 0; j < cityMap[i].length(); j++) { char cur = cityMap[i].charAt(j); int k = 1; if (!hash.containsKey(cur)) { hash.put(cur, k); } else { int prev = (int) hash.get(cur); hash.remove(cur); hash.put(cur, prev + 1); } } } Enumeration vals = hash.keys(); while (vals.hasMoreElements()) { char c = (char) vals.nextElement(); for (int i = 0; i < POIs.length; i++) { if (hash.get(c) == POIs[i]) { ans[i] = c; } } } String str = new String(ans); return str; }