Spring Framework example source code file (CollectionUtilsTests.java)

This example Spring Framework source code file (CollectionUtilsTests.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Spring Framework tags/keywords

arraylist, arraylist, collection, exception, instance, instance, integer, linkedlist, linkedlist, list, list, must, object, properties, util

The Spring Framework CollectionUtilsTests.java source code

/*
 * Copyright 2002-2007 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.util;

import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;

import junit.framework.TestCase;

/**
 * @author Rob Harrop
 * @author Juergen Hoeller
 * @author Rick Evans
 */
public class CollectionUtilsTests extends TestCase {

	public void testIsEmpty() {
		assertTrue(CollectionUtils.isEmpty((Set) null));
		assertTrue(CollectionUtils.isEmpty((Map) null));
		assertTrue(CollectionUtils.isEmpty(new HashMap()));
		assertTrue(CollectionUtils.isEmpty(new HashSet()));

		List list = new LinkedList();
		list.add(new Object());
		assertFalse(CollectionUtils.isEmpty(list));

		Map map = new HashMap();
		map.put("foo", "bar");
		assertFalse(CollectionUtils.isEmpty(map));
	}

	public void testMergeArrayIntoCollection() {
		Object[] arr = new Object[] {"value1", "value2"};
		List list = new LinkedList();
		list.add("value3");

		CollectionUtils.mergeArrayIntoCollection(arr, list);
		assertEquals("value3", list.get(0));
		assertEquals("value1", list.get(1));
		assertEquals("value2", list.get(2));
	}

	public void testMergePrimitiveArrayIntoCollection() {
		int[] arr = new int[] {1, 2};
		List list = new LinkedList();
		list.add(new Integer(3));

		CollectionUtils.mergeArrayIntoCollection(arr, list);
		assertEquals(new Integer(3), list.get(0));
		assertEquals(new Integer(1), list.get(1));
		assertEquals(new Integer(2), list.get(2));
	}

	public void testMergePropertiesIntoMap() {
		Properties defaults = new Properties();
		defaults.setProperty("prop1", "value1");
		Properties props = new Properties(defaults);
		props.setProperty("prop2", "value2");

		Map map = new HashMap();
		map.put("prop3", "value3");

		CollectionUtils.mergePropertiesIntoMap(props, map);
		assertEquals("value1", map.get("prop1"));
		assertEquals("value2", map.get("prop2"));
		assertEquals("value3", map.get("prop3"));
	}

	public void testContains() {
		assertFalse(CollectionUtils.contains((Iterator) null, "myElement"));
		assertFalse(CollectionUtils.contains((Enumeration) null, "myElement"));
		assertFalse(CollectionUtils.contains(new LinkedList().iterator(), "myElement"));
		assertFalse(CollectionUtils.contains(new Hashtable().keys(), "myElement"));

		List list = new LinkedList();
		list.add("myElement");
		assertTrue(CollectionUtils.contains(list.iterator(), "myElement"));

		Hashtable ht = new Hashtable();
		ht.put("myElement", "myValue");
		assertTrue(CollectionUtils.contains(ht.keys(), "myElement"));
	}

	public void testContainsAny() throws Exception {
		List source = new ArrayList();
		source.add("abc");
		source.add("def");
		source.add("ghi");

		List candidates = new ArrayList();
		candidates.add("xyz");
		candidates.add("def");
		candidates.add("abc");

		assertTrue(CollectionUtils.containsAny(source, candidates));
		candidates.remove("def");
		assertTrue(CollectionUtils.containsAny(source, candidates));
		candidates.remove("abc");
		assertFalse(CollectionUtils.containsAny(source, candidates));
	}

	public void testContainsInstanceWithNullCollection() throws Exception {
		assertFalse("Must return false if supplied Collection argument is null",
				CollectionUtils.containsInstance(null, this));
	}

	public void testContainsInstanceWithInstancesThatAreEqualButDistinct() throws Exception {
		List list = new ArrayList();
		list.add(new Instance("fiona"));
		assertFalse("Must return false if instance is not in the supplied Collection argument",
				CollectionUtils.containsInstance(list, new Instance("fiona")));
	}

	public void testContainsInstanceWithSameInstance() throws Exception {
		List list = new ArrayList();
		list.add(new Instance("apple"));
		Instance instance = new Instance("fiona");
		list.add(instance);
		assertTrue("Must return true if instance is in the supplied Collection argument",
				CollectionUtils.containsInstance(list, instance));
	}

	public void testContainsInstanceWithNullInstance() throws Exception {
		List list = new ArrayList();
		list.add(new Instance("apple"));
		list.add(new Instance("fiona"));
		assertFalse("Must return false if null instance is supplied",
				CollectionUtils.containsInstance(list, null));
	}

	public void testFindFirstMatch() throws Exception {
		List source = new ArrayList();
		source.add("abc");
		source.add("def");
		source.add("ghi");

		List candidates = new ArrayList();
		candidates.add("xyz");
		candidates.add("def");
		candidates.add("abc");

		assertEquals("def", CollectionUtils.findFirstMatch(source, candidates));
	}

	public void testHasUniqueObject() {
		List list = new LinkedList();
		list.add("myElement");
		list.add("myOtherElement");
		assertFalse(CollectionUtils.hasUniqueObject(list));

		list = new LinkedList();
		list.add("myElement");
		assertTrue(CollectionUtils.hasUniqueObject(list));

		list = new LinkedList();
		list.add("myElement");
		list.add(null);
		assertFalse(CollectionUtils.hasUniqueObject(list));

		list = new LinkedList();
		list.add(null);
		list.add("myElement");
		assertFalse(CollectionUtils.hasUniqueObject(list));

		list = new LinkedList();
		list.add(null);
		list.add(null);
		assertTrue(CollectionUtils.hasUniqueObject(list));

		list = new LinkedList();
		list.add(null);
		assertTrue(CollectionUtils.hasUniqueObject(list));

		list = new LinkedList();
		assertFalse(CollectionUtils.hasUniqueObject(list));
	}


	private static final class Instance {

		private final String name;

		public Instance(String name) {
			this.name = name;
		}

		public boolean equals(Object rhs) {
			if (this == rhs) {
				return true;
			}
			if (rhs == null || this.getClass() != rhs.getClass()) {
				return false;
			}
			Instance instance = (Instance) rhs;
			return this.name.equals(instance.name);
		}

		public int hashCode() {
			return this.name.hashCode();
		}
	}

}