Fix iterator and add tests for PagedList

azure-client-runtime/src/main/java/com/microsoft/azure/PagedList.java

@@ -67,65 +67,51 @@ public void loadAll() {
     }
 
     /**
-     * The implementation of {@link Iterator} for PagedList.
+     * The implementation of {@link ListIterator} for PagedList.
      */
-    private class Itr implements Iterator<E> {
-        /** The iterator for the actual list of items. */
-        private Iterator<E> itemsItr;
+    private class ListItr implements ListIterator<E> {
+        /** The list iterator for the actual list of items. */
+        private ListIterator<E> itemsListItr;
 
         /**
-         * Creates an instance of the iterator.
+         * Creates an instance of the ListIterator.
+         *
+         * @param index the position in the list to start.
          */
-        public Itr() {
-            itemsItr = items.iterator();
+        public ListItr(int index) {
+            itemsListItr = items.listIterator(index);
         }
 
         @Override
         public boolean hasNext() {
-            return itemsItr.hasNext() || nextPageLink != null;
+            return itemsListItr.hasNext() || nextPageLink != null;
         }
 
         @Override
         public E next() {
-            if (!itemsItr.hasNext()) {
+            if (!itemsListItr.hasNext()) {
                 if (nextPageLink == null) {
                     throw new NoSuchElementException();
                 } else {
                     try {
                         Page<E> nextPage = loadPage(nextPageLink);
                         nextPageLink = nextPage.getNextPageLink();
+                        int size = items.size();
                         addAll(nextPage.getItems());
-                        itemsItr = items.iterator();
+                        itemsListItr = items.listIterator(size);
                     } catch (CloudException e) {
                         throw new WebServiceException(e.toString(), e);
                     } catch (IOException e) {
                         throw new DataBindingException(e.getMessage(), e);
                     }
                 }
             }
-            return itemsItr.next();
+            return itemsListItr.next();
         }
 
         @Override
         public void remove() {
-            itemsItr.remove();
-        }
-    }
-
-    /**
-     * The implementation of {@link ListIterator} for PagedList.
-     */
-    private class ListItr extends Itr implements ListIterator<E> {
-        /** The list iterator for the actual list of items. */
-        private ListIterator<E> itemsListItr;
-
-        /**
-         * Creates an instance of the ListIterator.
-         *
-         * @param index the position in the list to start.
-         */
-        public ListItr(int index) {
-            itemsListItr = items.listIterator(index);
+            itemsListItr.remove();
         }
 
         @Override
@@ -178,7 +164,7 @@ public boolean contains(Object o) {
 
     @Override
     public Iterator<E> iterator() {
-        return new Itr();
+        return new ListItr(0);
     }
 
     @Override

azure-client-runtime/src/test/java/com/microsoft/azure/PagedListTests.java

@@ -0,0 +1,91 @@
+/**
+ *
+ * Copyright (c) Microsoft Corporation. All rights reserved.
+ * Licensed under the MIT License. See License.txt in the project root for license information.
+ *
+ */
+
+package com.microsoft.azure;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+public class PagedListTests {
+    private PagedList<Integer> list;
+
+    @Before
+    public void setupList() {
+        list = new PagedList<Integer>(new TestPage(0, 20)) {
+            @Override
+            public Page<Integer> loadPage(String nextPageLink) throws CloudException, IOException {
+                int pageNum = Integer.parseInt(nextPageLink);
+                return new TestPage(pageNum, 20);
+            }
+        };
+    }
+
+    @Test
+    public void sizeTest() {
+        Assert.assertEquals(20, list.size());
+    }
+
+    @Test
+    public void getTest() {
+        Assert.assertEquals(15, (int) list.get(15));
+    }
+
+    @Test
+    public void iterateTest() {
+        int j = 0;
+        for (int i : list) {
+            Assert.assertEquals(i, j++);
+        }
+    }
+
+    @Test
+    public void removeTest() {
+        Integer i = list.get(10);
+        list.remove(10);
+        Assert.assertEquals(19, list.size());
+        Assert.assertEquals(19, (int) list.get(18));
+    }
+
+    @Test
+    public void addTest() {
+        Integer i = list.get(10);
+        list.add(100);
+        Assert.assertEquals(21, list.size());
+        Assert.assertEquals(100, (int) list.get(11));
+        Assert.assertEquals(19, (int) list.get(20));
+    }
+
+    public static class TestPage implements Page<Integer> {
+        private int page;
+        private int max;
+
+        public TestPage(int page, int max) {
+            this.page = page;
+            this.max = max;
+        }
+
+        @Override
+        public String getNextPageLink() {
+            if (page + 1 == max) {
+                return null;
+            }
+            return Integer.toString(page + 1);
+        }
+
+        @Override
+        public List<Integer> getItems() {
+            List<Integer> items = new ArrayList<>();
+            items.add(page);
+            return items;
+        }
+    }
+}