INT-684, Added new OrderAwareLinkedHashSet and modified AbstractDispatcher

org.springframework.integration/src/test/java/org/springframework/integration/dispatcher/OrderedAwareLinkedHashSetTests.java

@@ -0,0 +1,145 @@
+/*
+ * Copyright 2002-2008 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.integration.dispatcher;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.Test;
+import org.springframework.core.Ordered;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Oleg Zhurakousky
+ * @since 1.0.3
+ */
+public class OrderedAwareLinkedHashSetTests {
+
+	/**
+	 * Tests that semantics of the LinkedHashSet were not broken
+	 */
+	@Test
+	public void testAddUnordered(){
+		OrderedAwareLinkedHashSet setToTest = new OrderedAwareLinkedHashSet();
+		setToTest.add("foo");
+		setToTest.add("bar");
+		setToTest.add("baz");
+		assertEquals(3, setToTest.size());
+		Object[] elements =  setToTest.toArray();
+		assertEquals("foo", elements[0]);
+		assertEquals("bar", elements[1]);
+		assertEquals("baz", elements[2]);
+	}
+	/**
+	 * Tests that semantics of TreeSet(Comparator) were not broken.
+	 * However, there is a special Comparator (instantiated by default) for this implementation of Set, 
+	 * which allows elements with the same "order" as long as these elements themselves are not equal.
+	 * In this case element with the same order will be placed to the right (appended next to) of 
+	 * the already existing element, thus preserving the order of insertion (LinkedHashset semantics) 
+	 * within the elements that have the same "order" value. 
+	 */
+	@Test
+	public void testAddOrdered(){
+		OrderedAwareLinkedHashSet setToTest = new OrderedAwareLinkedHashSet();
+		Object o1 = new Foo(3);
+		Object o2 = new Foo(1);
+		Object o3 = new Foo(2);
+		Object o4 = new Foo(2);
+		Object o5 = new Foo(Ordered.LOWEST_PRECEDENCE);
+		Object o6 = new Foo(Ordered.LOWEST_PRECEDENCE);
+		Object o7 = new Foo(Ordered.HIGHEST_PRECEDENCE);
+		Object o8 = new Foo(Ordered.HIGHEST_PRECEDENCE);
+		Object o9 = new Foo(4);
+		Object o10 = new Foo(2);
+		setToTest.add(o1);
+		setToTest.add(o2);
+		setToTest.add(o3);
+		setToTest.add(o4);
+		setToTest.add(o5);
+		setToTest.add(o6);
+		setToTest.add(o7);
+		setToTest.add(o8);
+		setToTest.add(o9);
+		setToTest.add(o10);		
+		assertEquals(10, setToTest.size());
+		System.out.println(setToTest);
+		Object[] elements = setToTest.toArray();
+		assertEquals(o7, elements[0]);
+		assertEquals(o8, elements[1]);
+		assertEquals(o2, elements[2]);
+		assertEquals(o3, elements[3]);
+		assertEquals(o4, elements[4]);
+		assertEquals(o10, elements[5]);
+		assertEquals(o1, elements[6]);
+		assertEquals(o9, elements[7]);
+		assertEquals(o5, elements[8]);
+		assertEquals(o6, elements[9]);
+	}
+	
+	@Test
+	public void testAddAllOrderedUnordered(){
+		List tempList = new ArrayList();
+		Object o1 = new Foo(3);
+		Object o2 = new Foo(1);
+		Object o3 = "FooA";
+		Object o4 = new Foo(2);
+		Object o5 = new Foo(Ordered.LOWEST_PRECEDENCE);
+		Object o6 = new Foo(Ordered.LOWEST_PRECEDENCE);
+		Object o7 = new Foo(Ordered.HIGHEST_PRECEDENCE);
+		Object o8 = new Foo(Ordered.HIGHEST_PRECEDENCE);
+		Object o9 = new Foo(4);
+		Object o10 = "FooB";
+		tempList.add(o1);
+		tempList.add(o2);
+		tempList.add(o3);
+		tempList.add(o4);
+		tempList.add(o5);
+		tempList.add(o6);
+		tempList.add(o7);
+		tempList.add(o8);
+		tempList.add(o9);
+		tempList.add(o10);		
+		assertEquals(10, tempList.size());
+		OrderedAwareLinkedHashSet orderAwareSet = new OrderedAwareLinkedHashSet();
+		orderAwareSet.addAll(tempList);
+		System.out.println(orderAwareSet);
+		Object[] elements = orderAwareSet.toArray();
+		assertEquals(o7, elements[0]);
+		assertEquals(o8, elements[1]);
+		assertEquals(o2, elements[2]);
+		assertEquals(o4, elements[3]);
+		assertEquals(o1, elements[4]);
+		assertEquals(o9, elements[5]);
+		assertEquals(o5, elements[6]);
+		assertEquals(o6, elements[7]);
+		assertEquals(o3, elements[8]);
+		assertEquals(o10, elements[9]);
+	}
+	
+	private static class Foo implements Ordered {
+		private int order;
+		public Foo(int order){
+			this.order = order;
+		}
+		public int getOrder() {
+			return order;
+		}	
+		public String toString(){
+			return "Foo-" + order;
+		}
+	}
+}