/**
* Prints a phrase on the grid nodes running anonymous closure objects and calculating total
* number of letters.
*
* @param phrase Phrase to print on of the grid nodes.
* @throws GridException If failed.
*/
private static void countLettersClosure(String phrase) throws GridException {
X.println(">>> Starting countLettersClosure() example...");
// Explicitly execute the collection of callable objects and receive a result.
Collection<Integer> results =
G.grid()
.call(
SPREAD,
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.
X.println(">>> Executing word: " + word);
// Return the length of a given word, i.e. number of letters.
return word.length();
}
},
Arrays.asList(phrase.split(" "))); // Collection of arguments for closures.
// Add up all results using convenience 'sum()' method.
int letterCnt = F.sum(results);
X.println(">>>");
X.println(">>> Finished execution of counting letters with closure based on GridGain 3.0 API.");
X.println(">>> You should see the phrase '" + phrase + "' printed out on the nodes.");
X.println(">>> Total number of letters in the phrase is '" + letterCnt + "'.");
X.println(">>> Check all nodes for output (this node is also part of the grid).");
X.println(">>>");
}
/**
* 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(">>>");
}
