ordering examples

Eugen Paraschiv · Eugen Paraschiv · commit 2a5442477d18 · 2013-10-25T12:41:23.000+03:00
diff --git a/guava/src/test/java/org/baeldung/guava/collections/GuavaOrderingExamplesTest.java b/guava/src/test/java/org/baeldung/guava/collections/GuavaOrderingExamplesTest.java
@@ -1,6 +1,7 @@
 package org.baeldung.guava.collections;
 
 import static org.hamcrest.Matchers.nullValue;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
@@ -25,6 +26,8 @@ public final int compare(final String s1, final String s2) {
 
     // tests
 
+    // dealing with null
+
     @Test
     public final void givenCollectionWithNulls_whenSortingWithNullsLast_thenNullsAreLast() {
         final List<Integer> toSort = Arrays.asList(3, 5, 4, null, 1, 2);
@@ -46,6 +49,18 @@ public final void whenCollectionIsSortedNullsLastReversed_thenNullAreFirst() {
         assertThat(toSort.get(0), nullValue());
     }
 
+    // natural ordering
+
+    @Test
+    public final void whenSortingWithNaturalOrdering_thenCorectlySorted() {
+        final List<Integer> toSort = Arrays.asList(3, 5, 4, 1, 2);
+        Collections.sort(toSort, Ordering.natural());
+
+        assertTrue(Ordering.natural().isOrdered(toSort));
+    }
+
+    // custom - by length
+
     @Test
     public final void givenCollectionIsSorted_whenUsingOrderingApiToCheckOrder_thenCheckCanBePerformed() {
         final List<String> toSort = Arrays.asList("zz", "aa", "b", "ccc");
@@ -78,4 +93,35 @@ public final void whenSortingCollectionsOfStringsByLenghtWithSecondaryNaturalOrd
         assertTrue(expectedOrder.isOrdered(toSort));
     }
 
+    @Test
+    public final void whenSortingCollectionsWithComplexOrderingExample_thenCorrectlySorted() {
+        final List<String> toSort = Arrays.asList("zz", "aa", null, "b", "ccc");
+
+        Collections.sort(toSort, new OrderingByLenght().reverse().compound(Ordering.natural()).nullsLast());
+        System.out.println(toSort);
+    }
+
+    // sorted copy
+
+    @Test
+    public final void givenUnorderdList_whenRetrievingSortedCopy_thenSorted() {
+        final List<String> toSort = Arrays.asList("aa", "b", "ccc");
+        final List<String> sortedCopy = new OrderingByLenght().sortedCopy(toSort);
+
+        final Ordering<String> expectedOrder = Ordering.explicit(Lists.newArrayList("b", "aa", "ccc"));
+        assertFalse(expectedOrder.isOrdered(toSort));
+        assertTrue(expectedOrder.isOrdered(sortedCopy));
+    }
+
+    // to string
+
+    @Test
+    public final void givenUnorderdList_whenUsingToStringForSortingObjects_thenSortedWithToString() {
+        final List<Integer> toSort = Arrays.asList(1, 2, 11);
+        Collections.sort(toSort, Ordering.usingToString());
+
+        final Ordering<Integer> expectedOrder = Ordering.explicit(Lists.newArrayList(1, 11, 2));
+        assertTrue(expectedOrder.isOrdered(toSort));
+    }
+
 }
