Use an accumulator in PrimeNumbersTask

griffon-plugins · Jan 18, 2016 · 4be6faa · 4be6faa
1 parent 1f5d1bb
commit 4be6faa
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Showing 2 changed files with 10 additions and 11 deletions.
diff --git a/subprojects/sample/griffon-app/controllers/org/example/SampleController.java b/subprojects/sample/griffon-app/controllers/org/example/SampleController.java
@@ -40,8 +40,7 @@ public void setModel(SampleModel model) {
     }
 
     public void start() {
-        PrimeNumbersTask task = new PrimeNumbersTask(model.getCount());
-        task.setPrimes(model.getPrimes());
+        PrimeNumbersTask task = new PrimeNumbersTask(model.getCount(), model.getPrimes());
         taskControl = taskManager.create(task);
         taskControl.getContext().addListener(new TaskListenerAdapter() {
             @Override
@@ -54,7 +53,6 @@ public void stateChanged(ChangeEvent<Task.State> event) {
                 switch (event.getNewValue()) {
                     case STARTED:
                         model.setRunning(true);
-                        model.getPrimes().clear();
                         break;
                     case DONE:
                     case CANCELLED:

diff --git a/subprojects/sample/src/main/java/org/example/PrimeNumbersTask.java b/subprojects/sample/src/main/java/org/example/PrimeNumbersTask.java
@@ -16,30 +16,31 @@
 package org.example;
 
 import griffon.plugins.tasks.Tracker;
-import javafx.collections.ObservableList;
 import org.codehaus.griffon.runtime.tasks.AbstractTask;
 
 import javax.annotation.Nonnull;
 import java.util.ArrayList;
 import java.util.List;
 
+import static griffon.util.GriffonClassUtils.requireState;
+import static java.util.Objects.requireNonNull;
+
 public class PrimeNumbersTask extends AbstractTask<List<Integer>, Integer> {
     private final int numbersToFind;
     private final List<Integer> numbers = new ArrayList<>();
-    private ObservableList<Integer> primes;
+    private final List<Integer> accumulator;
 
-    public PrimeNumbersTask(int numbersToFind) {
+    public PrimeNumbersTask(int numbersToFind, @Nonnull List<Integer> accumulator) {
         super(PrimeNumbersTask.class.getSimpleName() + "-" + System.currentTimeMillis());
+        requireState(numbersToFind > 0, "The quantity of prime numbers to find must be greater than zero");
         this.numbersToFind = numbersToFind;
-    }
-
-    public void setPrimes(ObservableList<Integer> primes) {
-        this.primes = primes;
+        this.accumulator = requireNonNull(accumulator, "Argument 'accumulator' must not be null");
     }
 
     @Override
     public List<Integer> execute(Tracker<Integer> tracker) throws Exception {
         int candidate = -1;
+        accumulator.clear();
         while (numbers.size() < numbersToFind) {
             candidate = nextPrimeNumber(++candidate);
             numbers.add(candidate);
@@ -52,7 +53,7 @@ public List<Integer> execute(Tracker<Integer> tracker) throws Exception {
 
     @Override
     public void process(@Nonnull List<Integer> chunks) {
-        primes.addAll(chunks);
+        accumulator.addAll(chunks);
     }
 
     private int nextPrimeNumber(int candidate) {