More lambdas, less boilerplate.

src/main/java/org/apache/commons/collections4/CollectionUtils.java

@@ -604,12 +604,7 @@ public class CollectionUtils {
         }
 
         @SuppressWarnings({ "unchecked", "rawtypes" })
-        final Transformer<E, ?> transformer = new Transformer() {
+        final Transformer<E, ?> transformer = input -> new EquatorWrapper(equator, input);
-            @Override
-            public EquatorWrapper<?> transform(final Object input) {
-                return new EquatorWrapper(equator, input);
-            }
-        };
 
         return isEqualCollection(collect(a, transformer), collect(b, transformer));
     }
@@ -1782,12 +1777,7 @@ public class CollectionUtils {
                                               final Iterable<? extends E> retain,
                                               final Equator<? super E> equator) {
 
-        final Transformer<E, EquatorWrapper<E>> transformer = new Transformer<E, EquatorWrapper<E>>() {
+        final Transformer<E, EquatorWrapper<E>> transformer = input -> new EquatorWrapper<>(equator, input);
-            @Override
-            public EquatorWrapper<E> transform(final E input) {
-                return new EquatorWrapper<>(equator, input);
-            }
-        };
 
         final Set<EquatorWrapper<E>> retainSet =
                 collect(retain, transformer, new HashSet<EquatorWrapper<E>>());
@@ -1860,12 +1850,7 @@ public class CollectionUtils {
                                               final Iterable<? extends E> remove,
                                               final Equator<? super E> equator) {
 
-        final Transformer<E, EquatorWrapper<E>> transformer = new Transformer<E, EquatorWrapper<E>>() {
+        final Transformer<E, EquatorWrapper<E>> transformer = input -> new EquatorWrapper<>(equator, input);
-            @Override
-            public EquatorWrapper<E> transform(final E input) {
-                return new EquatorWrapper<>(equator, input);
-            }
-        };
 
         final Set<EquatorWrapper<E>> removeSet =
                 collect(remove, transformer, new HashSet<EquatorWrapper<E>>());

src/main/java/org/apache/commons/collections4/SetUtils.java

@@ -125,12 +125,7 @@ public class SetUtils {
             throw new NullPointerException("Sets must not be null.");
         }
 
-        final Predicate<E> notContainedInB = new Predicate<E>() {
+        final Predicate<E> notContainedInB = object -> !b.contains(object);
-            @Override
-            public boolean evaluate(final E object) {
-                return !b.contains(object);
-            }
-        };
 
         return new SetView<E>() {
             @Override
@@ -285,12 +280,7 @@ public class SetUtils {
             throw new NullPointerException("Sets must not be null.");
         }
 
-        final Predicate<E> containedInB = new Predicate<E>() {
+        final Predicate<E> containedInB = object -> b.contains(object);
-            @Override
-            public boolean evaluate(final E object) {
-                return b.contains(object);
-            }
-        };
 
         return new SetView<E>() {
             @Override

src/main/java/org/apache/commons/collections4/map/MultiValueMap.java

@@ -438,23 +438,18 @@ public class MultiValueMap<K, V> extends AbstractMapDecorator<K, Object> impleme
                     return null;
                 }
                 final K key = keyIterator.next();
-                final Transformer<V, Entry<K, V>> transformer = new Transformer<V, Entry<K, V>>() {
+                final Transformer<V, Entry<K, V>> transformer = input -> new Entry<K, V>() {
                     @Override
-                    public Entry<K, V> transform(final V input) {
+                    public K getKey() {
-                        return new Entry<K, V>() {
+                        return key;
-                            @Override
+                    }
-                            public K getKey() {
+                    @Override
-                                return key;
+                    public V getValue() {
-                            }
+                        return input;
-                            @Override
+                    }
-                            public V getValue() {
+                    @Override
-                                return input;
+                    public V setValue(final V value) {
-                            }
+                        throw new UnsupportedOperationException();
-                            @Override
-                            public V setValue(final V value) {
-                                throw new UnsupportedOperationException();
-                            }
-                        };
                     }
                 };
                 return new TransformIterator<>(new ValuesIterator(key), transformer);

src/main/java/org/apache/commons/collections4/multimap/AbstractMultiValuedMap.java

@@ -626,14 +626,7 @@ public abstract class AbstractMultiValuedMap<K, V> implements MultiValuedMap<K,
                         return null;
                     }
                     final K key = keyIterator.next();
-                    final Transformer<V, Entry<K, V>> entryTransformer = new Transformer<V, Entry<K, V>>() {
+                    final Transformer<V, Entry<K, V>> entryTransformer = input -> new MultiValuedMapEntry(key, input);
-
-                        @Override
-                        public Entry<K, V> transform(final V input) {
-                            return new MultiValuedMapEntry(key, input);
-                        }
-
-                    };
                     return new TransformIterator<>(new ValuesIterator(key), entryTransformer);
                 }
             };

src/main/java/org/apache/commons/collections4/multiset/AbstractMultiSet.java

@@ -256,12 +256,7 @@ public abstract class AbstractMultiSet<E> extends AbstractCollection<E> implemen
      * @return the uniqueSet iterator
      */
     protected Iterator<E> createUniqueSetIterator() {
-        final Transformer<Entry<E>, E> transformer = new Transformer<Entry<E>, E>() {
+        final Transformer<Entry<E>, E> transformer = entry -> entry.getElement();
-            @Override
-            public E transform(final Entry<E> entry) {
-                return entry.getElement();
-            }
-        };
         return IteratorUtils.transformedIterator(entrySet().iterator(), transformer);
     }
 

src/test/java/org/apache/commons/collections4/CollectionUtilsTest.java

@@ -476,12 +476,7 @@ public class CollectionUtilsTest extends MockTestCase {
     @Test
     public void testSubtractWithPredicate() {
         // greater than 3
-        final Predicate<Number> predicate = new Predicate<Number>() {
+        final Predicate<Number> predicate = n -> n.longValue() > 3L;
-            @Override
-            public boolean evaluate(final Number n) {
-                return n.longValue() > 3L;
-            }
-        };
 
         final Collection<Number> col = CollectionUtils.subtract(iterableA, collectionC, predicate);
         final Map<Number, Integer> freq2 = CollectionUtils.getCardinalityMap(col);
@@ -733,22 +728,12 @@ public class CollectionUtilsTest extends MockTestCase {
 
         final Collection<String> strings = Arrays.asList("a", "b", "c");
         final StringBuffer result = new StringBuffer();
-        result.append(CollectionUtils.forAllButLastDo(strings, new Closure<String>() {
+        result.append(CollectionUtils.forAllButLastDo(strings, (Closure<String>) input -> result.append(input+";")));
-            @Override
-            public void execute(final String input) {
-                result.append(input+";");
-            }
-        }));
         assertEquals("a;b;c", result.toString());
 
         final Collection<String> oneString = Arrays.asList("a");
         final StringBuffer resultOne = new StringBuffer();
-        resultOne.append(CollectionUtils.forAllButLastDo(oneString, new Closure<String>() {
+        resultOne.append(CollectionUtils.forAllButLastDo(oneString, (Closure<String>) input -> resultOne.append(input+";")));
-            @Override
-            public void execute(final String input) {
-                resultOne.append(input+";");
-            }
-        }));
         assertEquals("a", resultOne.toString());
         assertNull(CollectionUtils.forAllButLastDo(strings, (Closure<String>) null)); // do not remove cast
         assertNull(CollectionUtils.forAllButLastDo((Collection<String>) null, (Closure<String>) null)); // do not remove cast
@@ -1108,12 +1093,7 @@ public class CollectionUtilsTest extends MockTestCase {
     }
 
     // -----------------------------------------------------------------------
-    private static Predicate<Number> EQUALS_TWO = new Predicate<Number>() {
+    private static Predicate<Number> EQUALS_TWO = input -> input.intValue() == 2;
-        @Override
-        public boolean evaluate(final Number input) {
-            return input.intValue() == 2;
-        }
-    };
 
 //Up to here
     @Test
@@ -1296,12 +1276,7 @@ public class CollectionUtilsTest extends MockTestCase {
         assertTrue(collection.contains(2L) && !collection.contains(1));
     }
 
-    Transformer<Object, Integer> TRANSFORM_TO_INTEGER = new Transformer<Object, Integer>() {
+    Transformer<Object, Integer> TRANSFORM_TO_INTEGER = input -> Integer.valueOf(((Long)input).intValue());
-        @Override
-        public Integer transform(final Object input) {
-            return Integer.valueOf(((Long)input).intValue());
-        }
-    };
 
     @Test
     public void transform1() {
@@ -1333,12 +1308,7 @@ public class CollectionUtilsTest extends MockTestCase {
         set.add(1L);
         set.add(2L);
         set.add(3L);
-        CollectionUtils.transform(set, new Transformer<Object, Integer>() {
+        CollectionUtils.transform(set, input -> 4);
-            @Override
-            public Integer transform(final Object input) {
-                return 4;
-            }
-        });
         assertEquals(1, set.size());
         assertEquals(4, set.iterator().next());
     }
@@ -1831,20 +1801,10 @@ public class CollectionUtilsTest extends MockTestCase {
         assertFalse(CollectionUtils.matchesAll(null, null));
         assertFalse(CollectionUtils.matchesAll(collectionA, null));
 
-        final Predicate<Integer> lessThanFive = new Predicate<Integer>() {
+        final Predicate<Integer> lessThanFive = object -> object < 5;
-            @Override
-            public boolean evaluate(final Integer object) {
-                return object < 5;
-            }
-        };
         assertTrue(CollectionUtils.matchesAll(collectionA, lessThanFive));
 
-        final Predicate<Integer> lessThanFour = new Predicate<Integer>() {
+        final Predicate<Integer> lessThanFour = object -> object < 4;
-            @Override
-            public boolean evaluate(final Integer object) {
-                return object < 4;
-            }
-        };
         assertFalse(CollectionUtils.matchesAll(collectionA, lessThanFour));
 
         assertTrue(CollectionUtils.matchesAll(null, lessThanFour));

src/test/java/org/apache/commons/collections4/FluentIterableTest.java

@@ -103,12 +103,7 @@ public class FluentIterableTest {
         emptyIterable = Collections.emptyList();
     }
 
-    private static Predicate<Number> EVEN = new Predicate<Number>() {
+    private static Predicate<Number> EVEN = input -> input.intValue() % 2 == 0;
-        @Override
-        public boolean evaluate(final Number input) {
-            return input.intValue() % 2 == 0;
-        }
-    };
 
     // -----------------------------------------------------------------------
     @Test
@@ -198,12 +193,7 @@ public class FluentIterableTest {
 
     @Test
     public void filter() {
-        final Predicate<Integer> smallerThan3 = new Predicate<Integer>() {
+        final Predicate<Integer> smallerThan3 = object -> object.intValue() < 3;
-            @Override
-            public boolean evaluate(final Integer object) {
-                return object.intValue() < 3;
-            }
-        };
         List<Integer> result = FluentIterable.of(iterableA).filter(smallerThan3).toList();
         assertEquals(3, result.size());
         assertEquals(Arrays.asList(1, 2, 2), result);
@@ -223,12 +213,7 @@ public class FluentIterableTest {
     @Test
     public void forEach() {
         final AtomicInteger sum = new AtomicInteger(0);
-        final Closure<Integer> closure = new Closure<Integer>() {
+        final Closure<Integer> closure = input -> sum.addAndGet(input);
-            @Override
-            public void execute(final Integer input) {
-                sum.addAndGet(input);
-            }
-        };
 
         FluentIterable.of(iterableA).forEach(closure);
         int expectedSum = 0;
@@ -315,12 +300,7 @@ public class FluentIterableTest {
 
     @Test
     public void transform() {
-        final Transformer<Integer, Integer> squared = new Transformer<Integer, Integer>() {
+        final Transformer<Integer, Integer> squared = object -> object * object;
-            @Override
-            public Integer transform(final Integer object) {
-                return object * object;
-            }
-        };
         List<Integer> result = FluentIterable.of(iterableA).transform(squared).toList();
         assertEquals(10, result.size());
         assertEquals(Arrays.asList(1, 4, 4, 9, 9, 9, 16, 16, 16, 16), result);

src/test/java/org/apache/commons/collections4/IterableUtilsTest.java

@@ -91,19 +91,9 @@ public class IterableUtilsTest {
         emptyIterable = Collections.emptyList();
     }
 
-    private static Predicate<Number> EQUALS_TWO = new Predicate<Number>() {
+    private static Predicate<Number> EQUALS_TWO = input -> input.intValue() == 2;
-        @Override
-        public boolean evaluate(final Number input) {
-            return input.intValue() == 2;
-        }
-    };
 
-    private static Predicate<Number> EVEN = new Predicate<Number>() {
+    private static Predicate<Number> EVEN = input -> input.intValue() % 2 == 0;
-        @Override
-        public boolean evaluate(final Number input) {
-            return input.intValue() % 2 == 0;
-        }
-    };
 
     // -----------------------------------------------------------------------
     @Test
@@ -373,20 +363,10 @@ public class IterableUtilsTest {
             // expected
         }
 
-        final Predicate<Integer> lessThanFive = new Predicate<Integer>() {
+        final Predicate<Integer> lessThanFive = object -> object < 5;
-            @Override
-            public boolean evaluate(final Integer object) {
-                return object < 5;
-            }
-        };
         assertTrue(IterableUtils.matchesAll(iterableA, lessThanFive));
 
-        final Predicate<Integer> lessThanFour = new Predicate<Integer>() {
+        final Predicate<Integer> lessThanFour = object -> object < 4;
-            @Override
-            public boolean evaluate(final Integer object) {
-                return object < 4;
-            }
-        };
         assertFalse(IterableUtils.matchesAll(iterableA, lessThanFour));
 
         assertTrue(IterableUtils.matchesAll(null, lessThanFour));
@@ -505,29 +485,18 @@ public class IterableUtilsTest {
         result = IterableUtils.toString(null);
         assertEquals("[]", result);
 
-        result = IterableUtils.toString(iterableA, new Transformer<Integer, String>() {
+        result = IterableUtils.toString(iterableA, input -> new Integer(input * 2).toString());
-            @Override
-            public String transform(final Integer input) {
-                return new Integer(input * 2).toString();
-            }
-        });
         assertEquals("[2, 4, 4, 6, 6, 6, 8, 8, 8, 8]", result);
 
-        result = IterableUtils.toString(new ArrayList<Integer>(), new Transformer<Integer, String>() {
+        result = IterableUtils.toString(new ArrayList<Integer>(), input -> {
-            @Override
+            fail("not supposed to reach here");
-            public String transform(final Integer input) {
+            return "";
-                fail("not supposed to reach here");
-                return "";
-            }
         });
         assertEquals("[]", result);
 
-        result = IterableUtils.toString(null, new Transformer<Integer, String>() {
+        result = IterableUtils.toString(null, input -> {
-            @Override
+            fail("not supposed to reach here");
-            public String transform(final Integer input) {
+            return "";
-                fail("not supposed to reach here");
-                return "";
-            }
         });
         assertEquals("[]", result);
     }
@@ -535,12 +504,7 @@ public class IterableUtilsTest {
     @Test
     public void testToStringDelimiter() {
 
-        final Transformer<Integer, String> transformer = new Transformer<Integer, String>() {
+        final Transformer<Integer, String> transformer = input -> new Integer(input * 2).toString();
-            @Override
-            public String transform(final Integer input) {
-                return new Integer(input * 2).toString();
-            }
-        };
 
         String result = IterableUtils.toString(iterableA, transformer, "", "", "");
         assertEquals("2446668888", result);
@@ -572,12 +536,9 @@ public class IterableUtilsTest {
 
     @Test
     public void testToStringWithNullArguments() {
-        final String result = IterableUtils.toString(null, new Transformer<Integer, String>() {
+        final String result = IterableUtils.toString(null, input -> {
-            @Override
+            fail("not supposed to reach here");
-            public String transform(final Integer input) {
+            return "";
-                fail("not supposed to reach here");
-                return "";
-            }
         }, "", "(", ")");
         assertEquals("()", result);
 
@@ -589,12 +550,9 @@ public class IterableUtilsTest {
         }
 
         try {
-            IterableUtils.toString(new ArrayList<Integer>(), new Transformer<Integer, String>() {
+            IterableUtils.toString(new ArrayList<Integer>(), input -> {
-                @Override
+                fail("not supposed to reach here");
-                public String transform(final Integer input) {
+                return "";
-                    fail("not supposed to reach here");
-                    return "";
-                }
             }, null, "(", ")");
             fail("expecting NullPointerException");
         } catch (final NullPointerException ex) {
@@ -602,12 +560,9 @@ public class IterableUtilsTest {
         }
 
         try {
-            IterableUtils.toString(new ArrayList<Integer>(), new Transformer<Integer, String>() {
+            IterableUtils.toString(new ArrayList<Integer>(), input -> {
-                @Override
+                fail("not supposed to reach here");
-                public String transform(final Integer input) {
+                return "";
-                    fail("not supposed to reach here");
-                    return "";
-                }
             }, "", null, ")");
             fail("expecting NullPointerException");
         } catch (final NullPointerException ex) {
@@ -615,12 +570,9 @@ public class IterableUtilsTest {
         }
 
         try {
-            IterableUtils.toString(new ArrayList<Integer>(), new Transformer<Integer, String>() {
+            IterableUtils.toString(new ArrayList<Integer>(), input -> {
-                @Override
+                fail("not supposed to reach here");
-                public String transform(final Integer input) {
+                return "";
-                    fail("not supposed to reach here");
-                    return "";
-                }
             }, "", "(", null);
             fail("expecting NullPointerException");
         } catch (final NullPointerException ex) {

src/test/java/org/apache/commons/collections4/ListUtilsTest.java

@@ -122,12 +122,7 @@ public class ListUtilsTest {
 
     @Test
     public void testPredicatedList() {
-        final Predicate<Object> predicate = new Predicate<Object>() {
+        final Predicate<Object> predicate = o -> o instanceof String;
-            @Override
-            public boolean evaluate(final Object o) {
-                return o instanceof String;
-            }
-        };
         final List<Object> list = ListUtils.predicatedList(new ArrayList<>(), predicate);
         assertTrue("returned object should be a PredicatedList", list instanceof PredicatedList);
         try {
@@ -452,12 +447,7 @@ public class ListUtilsTest {
         assertEquals(strings, partitionMax.get(0));
     }
 
-    private static Predicate<Number> EQUALS_TWO = new Predicate<Number>() {
+    private static Predicate<Number> EQUALS_TWO = input -> input.intValue() == 2;
-        @Override
-        public boolean evaluate(final Number input) {
-            return input.intValue() == 2;
-        }
-    };
 
     @Test
     @SuppressWarnings("boxing") // OK in test code

src/test/java/org/apache/commons/collections4/MapUtilsTest.java

@@ -65,12 +65,7 @@ public class MapUtilsTest extends AbstractAvailableLocalesTest {
     }
 
     public Predicate<Object> getPredicate() {
-        return new Predicate<Object>() {
+        return o -> o instanceof String;
-            @Override
-            public boolean evaluate(final Object o) {
-                return o instanceof String;
-            }
-        };
     }
 
     @Test
@@ -122,14 +117,11 @@ public class MapUtilsTest extends AbstractAvailableLocalesTest {
 
     @Test
     public void testLazyMapTransformer() {
-        final Map<Object, Object> map = MapUtils.lazyMap(new HashMap<>(), new Transformer<Object, Object>() {
+        final Map<Object, Object> map = MapUtils.lazyMap(new HashMap<>(), (Transformer<Object, Object>) mapKey -> {
-            @Override
+            if (mapKey instanceof String) {
-            public Object transform(final Object mapKey) {
+                return Integer.valueOf((String) mapKey);
-                if (mapKey instanceof String) {
-                    return Integer.valueOf((String) mapKey);
-                }
-                return null;
             }
+            return null;
         });
 
         assertEquals(0, map.size());
@@ -859,12 +851,7 @@ public class MapUtilsTest extends AbstractAvailableLocalesTest {
 
         // Now test key transform population
         final MultiValueMap<Integer, X> map = MultiValueMap.multiValueMap(new TreeMap<Integer, Collection<X>>());
-        MapUtils.populateMap(map, list, new Transformer<X, Integer>() {
+        MapUtils.populateMap(map, list, (Transformer<X, Integer>) input -> input.key, TransformerUtils.<X> nopTransformer());
-            @Override
-            public Integer transform(final X input) {
-                return input.key;
-            }
-        }, TransformerUtils.<X> nopTransformer());
         assertEquals(list.size(), map.totalSize());
 
         for (int i = 0; i < list.size(); i++) {

src/test/java/org/apache/commons/collections4/MultiSetUtilsTest.java

@@ -92,12 +92,7 @@ public class MultiSetUtilsTest {
      */
     @Test
     public void testPredicatedMultiSet() {
-        final Predicate<String> predicate = new Predicate<String>() {
+        final Predicate<String> predicate = object -> object.length() == 1;
-            @Override
-            public boolean evaluate(final String object) {
-                return object.length() == 1;
-            };
-        };
         final MultiSet<String> predicated = MultiSetUtils.predicatedMultiSet(multiSet, predicate);
         assertEquals(multiSet.size(), predicated.size());
         assertEquals(multiSet.getCount("a"), predicated.getCount("a"));
@@ -115,12 +110,7 @@ public class MultiSetUtilsTest {
         }
 
         try {
-            MultiSetUtils.predicatedMultiSet(multiSet, new Predicate<String>() {
+            MultiSetUtils.predicatedMultiSet(multiSet, object -> object.equals("a"));
-                @Override
-                public boolean evaluate(final String object) {
-                    return object.equals("a");
-                };
-            });
             fail("Predicate is violated for all elements not being 'a'");
         }
         catch (final IllegalArgumentException iae) {

src/test/java/org/apache/commons/collections4/SetUtilsTest.java

@@ -231,12 +231,7 @@ public class SetUtilsTest {
 
     @Test
     public void testpredicatedSet() {
-        final Predicate<Object> predicate = new Predicate<Object>() {
+        final Predicate<Object> predicate = o -> o instanceof String;
-            @Override
-            public boolean evaluate(final Object o) {
-                return o instanceof String;
-            }
-        };
         final Set<Object> set = SetUtils.predicatedSet(new HashSet<>(), predicate);
         assertTrue("returned object should be a PredicatedSet", set instanceof PredicatedSet);
         try {

src/test/java/org/apache/commons/collections4/SplitMapUtilsTest.java

@@ -41,12 +41,7 @@ public class SplitMapUtilsTest {
     private Map<String, Integer> backingMap;
     private TransformedSplitMap<String, String, String, Integer> transformedMap;
 
-    private final Transformer<String, Integer> stringToInt = new Transformer<String, Integer>() {
+    private final Transformer<String, Integer> stringToInt = input -> Integer.valueOf(input);
-        @Override
-        public Integer transform(final String input) {
-            return Integer.valueOf(input);
-        }
-    };
 
     @Before
     public void setUp() throws Exception {
@@ -84,32 +79,17 @@ public class SplitMapUtilsTest {
         // check individual operations
         int sz = map.size();
 
-        attemptPutOperation(new Runnable() {
+        attemptPutOperation(() -> map.clear());
-            @Override
-            public void run() {
-                map.clear();
-            }
-        });
 
         assertEquals(sz, map.size());
 
-        attemptPutOperation(new Runnable() {
+        attemptPutOperation(() -> map.put("foo", 100));
-            @Override
-            public void run() {
-                map.put("foo", 100);
-            }
-        });
 
         final HashMap<String, Integer> m = new HashMap<>();
         m.put("foo", 100);
         m.put("bar", 200);
         m.put("baz", 300);
-        attemptPutOperation(new Runnable() {
+        attemptPutOperation(() -> map.putAll(m));
-            @Override
-            public void run() {
-                map.putAll(m);
-            }
-        });
 
         // equals, hashcode
         final IterableMap<String, Integer> other = SplitMapUtils.readableMap(transformedMap);
@@ -135,60 +115,15 @@ public class SplitMapUtilsTest {
     @SuppressWarnings("unchecked")
     public void testWritableMap() {
         final Map<String, String> map = SplitMapUtils.writableMap(transformedMap);
-        attemptGetOperation(new Runnable() {
+        attemptGetOperation(() -> map.get(null));
-            @Override
+        attemptGetOperation(() -> map.entrySet());
-            public void run() {
+        attemptGetOperation(() -> map.keySet());
-                map.get(null);
+        attemptGetOperation(() -> map.values());
-            }
+        attemptGetOperation(() -> map.size());
-        });
+        attemptGetOperation(() -> map.isEmpty());
-        attemptGetOperation(new Runnable() {
+        attemptGetOperation(() -> map.containsKey(null));
-            @Override
+        attemptGetOperation(() -> map.containsValue(null));
-            public void run() {
+        attemptGetOperation(() -> map.remove(null));
-                map.entrySet();
-            }
-        });
-        attemptGetOperation(new Runnable() {
-            @Override
-            public void run() {
-                map.keySet();
-            }
-        });
-        attemptGetOperation(new Runnable() {
-            @Override
-            public void run() {
-                map.values();
-            }
-        });
-        attemptGetOperation(new Runnable() {
-            @Override
-            public void run() {
-                map.size();
-            }
-        });
-        attemptGetOperation(new Runnable() {
-            @Override
-            public void run() {
-                map.isEmpty();
-            }
-        });
-        attemptGetOperation(new Runnable() {
-            @Override
-            public void run() {
-                map.containsKey(null);
-            }
-        });
-        attemptGetOperation(new Runnable() {
-            @Override
-            public void run() {
-                map.containsValue(null);
-            }
-        });
-        attemptGetOperation(new Runnable() {
-            @Override
-            public void run() {
-                map.remove(null);
-            }
-        });
 
         // equals, hashcode
         final Map<String, String> other = SplitMapUtils.writableMap(transformedMap);

src/test/java/org/apache/commons/collections4/TransformerUtilsTest.java

@@ -247,12 +247,7 @@ public class TransformerUtilsTest {
         assertEquals("A", TransformerUtils.ifTransformer(TruePredicate.truePredicate(), a, b).transform(null));
         assertEquals("B", TransformerUtils.ifTransformer(FalsePredicate.falsePredicate(), a, b).transform(null));
 
-        final Predicate<Integer> lessThanFivePredicate = new Predicate<Integer>() {
+        final Predicate<Integer> lessThanFivePredicate = value -> value < 5;
-            @Override
-            public boolean evaluate(final Integer value) {
-                return value < 5;
-            }
-        };
         // if/else tests
         assertEquals("A", TransformerUtils.<Integer, String>ifTransformer(lessThanFivePredicate, a, b).transform(1));
         assertEquals("B", TransformerUtils.<Integer, String>ifTransformer(lessThanFivePredicate, a, b).transform(5));

src/test/java/org/apache/commons/collections4/bag/PredicatedBagTest.java

@@ -44,12 +44,7 @@ public class PredicatedBagTest<T> extends AbstractBagTest<T> {
     //--------------------------------------------------------------------------
 
     protected Predicate<T> stringPredicate() {
-        return new Predicate<T>() {
+        return o -> o instanceof String;
-            @Override
-            public boolean evaluate(final T o) {
-                return o instanceof String;
-            }
-        };
     }
 
     protected Predicate<T> truePredicate = TruePredicate.<T>truePredicate();

src/test/java/org/apache/commons/collections4/bag/PredicatedSortedBagTest.java

@@ -46,12 +46,7 @@ public class PredicatedSortedBagTest<T> extends AbstractSortedBagTest<T> {
     //--------------------------------------------------------------------------
 
     protected Predicate<T> stringPredicate() {
-        return new Predicate<T>() {
+        return o -> o instanceof String;
-            @Override
-            public boolean evaluate(final T o) {
-                return o instanceof String;
-            }
-        };
     }
 
     protected Predicate<T> truePredicate = TruePredicate.<T>truePredicate();

src/test/java/org/apache/commons/collections4/bag/TreeBagTest.java

@@ -16,8 +16,6 @@
  */
 package org.apache.commons.collections4.bag;
 
-import java.util.Comparator;
-
 import junit.framework.Test;
 
 import org.apache.commons.collections4.Bag;
@@ -75,12 +73,7 @@ public class TreeBagTest<T> extends AbstractSortedBagTest<T> {
             // expected;
         }
 
-        final Bag<String> bag2 = new TreeBag<>(new Comparator<String>() {
+        final Bag<String> bag2 = new TreeBag<>((o1, o2) -> o1.compareTo(o2));
-            @Override
-            public int compare(final String o1, final String o2) {
-                return o1.compareTo(o2);
-            }
-        });
         try {
             // jdk bug: adding null to an empty TreeMap works
             // thus ensure that the bag is not empty before adding null

src/test/java/org/apache/commons/collections4/collection/PredicatedCollectionTest.java

@@ -76,12 +76,7 @@ public class PredicatedCollectionTest<E> extends AbstractCollectionTest<E> {
 
     //-----------------------------------------------------------------------
     protected Predicate<E> testPredicate =
-        new Predicate<E>() {
+        o -> o instanceof String;
-            @Override
-            public boolean evaluate(final E o) {
-                return o instanceof String;
-            }
-        };
 
     public Collection<E> makeTestCollection() {
         return decorateCollection(new ArrayList<E>(), testPredicate);

src/test/java/org/apache/commons/collections4/comparators/ComparatorChainTest.java

@@ -103,18 +103,15 @@ public class ComparatorChainTest extends AbstractComparatorTest<ComparatorChainT
         // -1 * Integer.MIN_VALUE is less than 0,
         // test that ComparatorChain handles this edge case correctly
         final ComparatorChain<Integer> chain = new ComparatorChain<>();
-        chain.addComparator(new Comparator<Integer>() {
+        chain.addComparator((a, b) -> {
-            @Override
+            final int result = a.compareTo(b);
-            public int compare(final Integer a, final Integer b) {
+            if (result < 0) {
-                final int result = a.compareTo(b);
+                return Integer.MIN_VALUE;
-                if (result < 0) {
-                    return Integer.MIN_VALUE;
-                }
-                if (result > 0) {
-                    return Integer.MAX_VALUE;
-                }
-                return 0;
             }
+            if (result > 0) {
+                return Integer.MAX_VALUE;
+            }
+            return 0;
         }, true);
 
         assertTrue(chain.compare(Integer.valueOf(4), Integer.valueOf(5)) > 0);

src/test/java/org/apache/commons/collections4/iterators/FilterIteratorTest.java

@@ -157,16 +157,13 @@ public class FilterIteratorTest<E> extends AbstractIteratorTest<E> {
     }
 
     private void verifyElementsInPredicate(final String[] elements) {
-        final Predicate<E> pred = new Predicate<E>() {
+        final Predicate<E> pred = x -> {
-            @Override
+            for (final String element : elements) {
-            public boolean evaluate(final E x) {
+                if (element.equals(x)) {
-                for (final String element : elements) {
+                    return true;
-                    if (element.equals(x)) {
-                        return true;
-                    }
                 }
-                return false;
             }
+            return false;
         };
         initIterator();
         iterator.setPredicate(pred);
@@ -199,10 +196,7 @@ public class FilterIteratorTest<E> extends AbstractIteratorTest<E> {
      * @return "filtered" iterator
      */
     protected FilterIterator<E> makePassThroughFilter(final Iterator<E> i) {
-        final Predicate<E> pred = new Predicate<E>() {
+        final Predicate<E> pred = x -> true;
-                @Override
-                public boolean evaluate(final E x) { return true; }
-        };
         return new FilterIterator<>(i, pred);
     }
 
@@ -214,10 +208,7 @@ public class FilterIteratorTest<E> extends AbstractIteratorTest<E> {
      * @return "filtered" iterator
      */
     protected FilterIterator<E> makeBlockAllFilter(final Iterator<E> i) {
-        final Predicate<E> pred = new Predicate<E>() {
+        final Predicate<E> pred = x -> false;
-                @Override
-                public boolean evaluate(final E x) { return false; }
-        };
         return new FilterIterator<>(i, pred);
     }
 }

src/test/java/org/apache/commons/collections4/iterators/FilterListIteratorTest.java

@@ -70,47 +70,17 @@ public class FilterListIteratorTest {
             if (i % 6 == 0) { sixes.add(Integer.valueOf(i)); }
         }
 
-        truePred = new Predicate<Integer>() {
+        truePred = x -> true;
-            @Override
-            public boolean evaluate(final Integer x) {
-                return true;
-            }
-        };
 
-        falsePred = new Predicate<Integer>() {
+        falsePred = x -> true;
-            @Override
-            public boolean evaluate(final Integer x) {
-                return true;
-            }
-        };
 
-        evenPred = new Predicate<Integer>() {
+        evenPred = x -> x % 2 == 0;
-            @Override
-            public boolean evaluate(final Integer x) {
-                return x % 2 == 0;
-            }
-        };
 
-        oddPred = new Predicate<Integer>() {
+        oddPred = x -> x % 2 != 0;
-            @Override
-            public boolean evaluate(final Integer x) {
-                return x % 2 != 0; //works for all numbers, not just >= 0 as is the case for "x % 2 == 1"
-            }
-        };
 
-        threePred = new Predicate<Integer>() {
+        threePred = x -> x % 3 == 0;
-            @Override
-            public boolean evaluate(final Integer x) {
-                return x % 3 == 0;
-            }
-        };
 
-        fourPred = new Predicate<Integer>() {
+        fourPred = x -> x % 4 == 0;
-            @Override
-            public boolean evaluate(final Integer x) {
-                return x % 4 == 0;
-            }
-        };
 
     }
 

src/test/java/org/apache/commons/collections4/iterators/IteratorChainTest.java

@@ -91,12 +91,7 @@ public class IteratorChainTest extends AbstractIteratorTest<String> {
 
     public void testRemoveFromFilteredIterator() {
 
-        final Predicate<Integer> myPredicate = new Predicate<Integer>() {
+        final Predicate<Integer> myPredicate = i -> i.compareTo(Integer.valueOf(4)) < 0;
-            @Override
-            public boolean evaluate(final Integer i) {
-                return i.compareTo(Integer.valueOf(4)) < 0;
-            }
-        };
 
         final List<Integer> list1 = new ArrayList<>();
         final List<Integer> list2 = new ArrayList<>();

src/test/java/org/apache/commons/collections4/iterators/LazyIteratorChainTest.java

@@ -105,12 +105,7 @@ public class LazyIteratorChainTest extends AbstractIteratorTest<String> {
 
     public void testRemoveFromFilteredIterator() {
 
-        final Predicate<Integer> myPredicate = new Predicate<Integer>() {
+        final Predicate<Integer> myPredicate = i -> i.compareTo(Integer.valueOf(4)) < 0;
-            @Override
-            public boolean evaluate(final Integer i) {
-                return i.compareTo(Integer.valueOf(4)) < 0;
-            }
-        };
 
         final List<Integer> list1 = new ArrayList<>();
         final List<Integer> list2 = new ArrayList<>();

src/test/java/org/apache/commons/collections4/list/PredicatedListTest.java

@@ -56,12 +56,7 @@ public class PredicatedListTest<E> extends AbstractListTest<E> {
 //--------------------------------------------------------------------
 
     protected Predicate<E> testPredicate =
-        new Predicate<E>() {
+        o -> o instanceof String;
-            @Override
-            public boolean evaluate(final E o) {
-                return o instanceof String;
-            }
-        };
 
     public List<E> makeTestList() {
         return decorateList(new ArrayList<E>(), testPredicate);

src/test/java/org/apache/commons/collections4/map/DefaultedMapTest.java

@@ -104,14 +104,11 @@ public class DefaultedMapTest<K, V> extends AbstractIterableMapTest<K, V> {
     @SuppressWarnings("unchecked")
     public void testMapGet4() {
         final HashMap<K, V> base = new HashMap<>();
-        final Map<K, V> map = DefaultedMap.defaultedMap(base, new Transformer<K, V>() {
+        final Map<K, V> map = DefaultedMap.defaultedMap(base, (Transformer<K, V>) input -> {
-            @Override
+            if (input instanceof String) {
-            public V transform(final K input) {
+                return (V) "NULL";
-                if (input instanceof String) {
-                    return (V) "NULL";
-                }
-                return (V) "NULL_OBJECT";
             }
+            return (V) "NULL_OBJECT";
         });
 
         assertEquals(0, map.size());

src/test/java/org/apache/commons/collections4/map/LazyMapTest.java

@@ -72,12 +72,7 @@ public class LazyMapTest<K, V> extends AbstractIterableMapTest<K, V> {
 
     @Test
     public void mapGetWithTransformer() {
-        final Transformer<Number, Integer> intConverter = new Transformer<Number, Integer>(){
+        final Transformer<Number, Integer> intConverter = input -> input.intValue();
-            @Override
-            public Integer transform(final Number input) {
-                return input.intValue();
-            }
-        };
         final Map<Long, Number> map = lazyMap(new HashMap<Long,Number>(), intConverter );
         assertEquals(0, map.size());
         final Number i1 = map.get(123L);

src/test/java/org/apache/commons/collections4/map/PredicatedMapTest.java

@@ -34,12 +34,7 @@ public class PredicatedMapTest<K, V> extends AbstractIterableMapTest<K, V> {
 
     protected static final Predicate<Object> truePredicate = TruePredicate.<Object>truePredicate();
 
-    protected static final Predicate<Object> testPredicate = new Predicate<Object>() {
+    protected static final Predicate<Object> testPredicate = o -> o instanceof String;
-        @Override
-        public boolean evaluate(final Object o) {
-            return o instanceof String;
-        }
-    };
 
     public PredicatedMapTest(final String testName) {
         super(testName);

src/test/java/org/apache/commons/collections4/map/PredicatedSortedMapTest.java

@@ -36,12 +36,7 @@ public class PredicatedSortedMapTest<K, V> extends AbstractSortedMapTest<K, V> {
 
     protected static final Predicate<Object> truePredicate = TruePredicate.truePredicate();
 
-    protected static final Predicate<Object> testPredicate = new Predicate<Object>() {
+    protected static final Predicate<Object> testPredicate = o -> o instanceof String;
-        @Override
-        public boolean evaluate(final Object o) {
-            return o instanceof String;
-        }
-    };
 
     public PredicatedSortedMapTest(final String testName) {
         super(testName);

src/test/java/org/apache/commons/collections4/multiset/PredicatedMultiSetTest.java

@@ -44,12 +44,7 @@ public class PredicatedMultiSetTest<T> extends AbstractMultiSetTest<T> {
     //--------------------------------------------------------------------------
 
     protected Predicate<T> stringPredicate() {
-        return new Predicate<T>() {
+        return o -> o instanceof String;
-            @Override
-            public boolean evaluate(final T o) {
-                return o instanceof String;
-            }
-        };
     }
 
     protected Predicate<T> truePredicate = TruePredicate.<T>truePredicate();

src/test/java/org/apache/commons/collections4/queue/PredicatedQueueTest.java

@@ -73,12 +73,7 @@ public class PredicatedQueueTest<E> extends AbstractQueueTest<E> {
     //------------------------------------------------------------
 
     protected Predicate<E> testPredicate =
-            new Predicate<E>() {
+            o -> o instanceof String;
-                @Override
-                public boolean evaluate(final E o) {
-                    return o instanceof String;
-                }
-            };
 
     public Queue<E> makeTestQueue() {
         return decorateCollection(new LinkedList<E>(), testPredicate);

src/test/java/org/apache/commons/collections4/set/PredicatedNavigableSetTest.java

@@ -62,12 +62,7 @@ public class PredicatedNavigableSetTest<E> extends AbstractNavigableSetTest<E> {
 
 //--------------------------------------------------------------------
     protected Predicate<E> testPredicate =
-        new Predicate<E>() {
+        o -> o instanceof String && ((String) o).startsWith("A");
-            @Override
-            public boolean evaluate(final E o) {
-                return o instanceof String && ((String) o).startsWith("A");
-            }
-        };
 
     protected PredicatedNavigableSet<E> makeTestSet() {
         return PredicatedNavigableSet.predicatedNavigableSet(new TreeSet<E>(), testPredicate);

src/test/java/org/apache/commons/collections4/set/PredicatedSetTest.java

@@ -56,12 +56,7 @@ public class PredicatedSetTest<E> extends AbstractSetTest<E> {
 //--------------------------------------------------------------------
 
     protected Predicate<E> testPredicate =
-        new Predicate<E>() {
+        o -> o instanceof String;
-            @Override
-            public boolean evaluate(final E o) {
-                return o instanceof String;
-            }
-        };
 
     protected PredicatedSet<E> makeTestSet() {
         return decorateSet(new HashSet<E>(), testPredicate);

src/test/java/org/apache/commons/collections4/set/PredicatedSortedSetTest.java

@@ -62,12 +62,7 @@ public class PredicatedSortedSetTest<E> extends AbstractSortedSetTest<E> {
 
 //--------------------------------------------------------------------
     protected Predicate<E> testPredicate =
-        new Predicate<E>() {
+        o -> o instanceof String && ((String) o).startsWith("A");
-            @Override
-            public boolean evaluate(final E o) {
-                return o instanceof String && ((String) o).startsWith("A");
-            }
-        };
 
     protected PredicatedSortedSet<E> makeTestSet() {
         return PredicatedSortedSet.predicatedSortedSet(new TreeSet<E>(), testPredicate);

src/test/java/org/apache/commons/collections4/splitmap/TransformedSplitMapTest.java

@@ -35,26 +35,11 @@ import org.apache.commons.collections4.functors.NOPTransformer;
 @SuppressWarnings("boxing")
 public class TransformedSplitMapTest extends BulkTest {
 
-    private final Transformer<Integer, String> intToString = new Transformer<Integer, String>() {
+    private final Transformer<Integer, String> intToString = input -> String.valueOf(input);
-        @Override
-        public String transform(final Integer input) {
-            return String.valueOf(input);
-        }
-    };
 
-    private final Transformer<Object, Class<?>> objectToClass = new Transformer<Object, Class<?>>() {
+    private final Transformer<Object, Class<?>> objectToClass = input -> input == null ? null : input.getClass();
-        @Override
-        public java.lang.Class<?> transform(final Object input) {
-            return input == null ? null : input.getClass();
-        }
-    };
 
-    private final Transformer<String, Integer> stringToInt = new Transformer<String, Integer>() {
+    private final Transformer<String, Integer> stringToInt = input -> Integer.valueOf(input);
-        @Override
-        public Integer transform(final String input) {
-            return Integer.valueOf(input);
-        }
-    };
 
     public TransformedSplitMapTest(final String testName) {
         super(testName);