/** * Calculates length of a given phrase on the grid. * * @param phrase Phrase to count the number of letters in. * @throws GridException If failed. */ private static void countLettersReducer(String phrase) throws GridException { X.println(">>> Starting countLettersReducer() example..."); Grid grid = G.grid(); // Logger to use in your closure. Note that even though we assign it // to a local variable, GridGain still allows to use it from remotely // executed code. final GridLogger log = grid.log(); // Execute Hello World task. int letterCnt = grid.reduce( BALANCE, new GridClosure<String, Integer>() { // Create executable logic. @Override public Integer apply(String word) { // Print out a given word, just so we can // see which node is doing what. log.info(">>> Calculating for word: " + word); // Return the length of a given word, i.e. number of letters. return word.length(); } }, Arrays.asList(phrase.split(" ")), // Collection of words. // Create custom reducer. // NOTE: Alternatively, you can use existing reducer: F.sumIntReducer() new GridReducer<Integer, Integer>() { private int sum; @Override public boolean collect(Integer res) { sum += res; return true; // True means continue collecting until last result. } @Override public Integer apply() { return sum; } }); X.println(">>>"); X.println(">>> Finished execution of counting letters with reducer based on GridGain 3.0 API."); X.println(">>> Total number of letters in the phrase is '" + letterCnt + "'."); X.println(">>> You should see individual words printed out on different nodes."); X.println(">>> Check all nodes for output (this node is also part of the grid)."); X.println(">>>"); }