[BAEL-9550] - Moved articles and codes from core-java-collections module to java-collections-convversions and java-collections-maps module
This commit is contained in:
amit2103
@@ -0,0 +1,60 @@
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package com.baeldung.collection;
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import java.util.ConcurrentModificationException;
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import java.util.HashMap;
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import java.util.Iterator;
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import java.util.Map;
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import java.util.TreeMap;
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import org.hamcrest.Matchers;
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import org.junit.Assert;
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import org.junit.Test;
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public class WhenComparingTreeMapVsHashMap {
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@Test
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public void whenInsertObjectsTreeMap_thenNaturalOrder() {
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Map<Integer, String> treemap = new TreeMap<>();
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treemap.put(3, "TreeMap");
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treemap.put(2, "vs");
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treemap.put(1, "HashMap");
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Assert.assertThat(treemap.keySet(), Matchers.contains(1, 2, 3));
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}
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@Test(expected = NullPointerException.class)
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public void whenInsertNullInTreeMap_thenException() {
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Map<Integer, String> treemap = new TreeMap<>();
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treemap.put(null, "NullPointerException");
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}
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@Test
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public void whenInsertObjectsHashMap_thenRandomOrder() {
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Map<Integer, String> hashmap = new HashMap<>();
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hashmap.put(3, "TreeMap");
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hashmap.put(2, "vs");
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hashmap.put(1, "HashMap");
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Assert.assertThat(hashmap.keySet(), Matchers.containsInAnyOrder(1, 2, 3));
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}
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@Test
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public void whenInsertNullInHashMap_thenInsertsNull() {
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Map<Integer, String> hashmap = new HashMap<>();
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hashmap.put(null, null);
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Assert.assertNull(hashmap.get(null));
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}
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@Test
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public void givenHashMapAndTreeMap_whenputDuplicates_thenOnlyUnique() {
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Map<Integer, String> treeMap = new HashMap<>();
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treeMap.put(1, "Baeldung");
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treeMap.put(1, "Baeldung");
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Assert.assertTrue(treeMap.size() == 1);
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Map<Integer, String> treeMap2 = new TreeMap<>();
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treeMap2.put(1, "Baeldung");
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treeMap2.put(1, "Baeldung");
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Assert.assertTrue(treeMap2.size() == 1);
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}
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}
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@@ -0,0 +1,29 @@
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package com.baeldung.java.map;
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import static org.junit.Assert.assertFalse;
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import static org.junit.Assert.assertNull;
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import static org.junit.Assert.assertTrue;
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import java.util.Collections;
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import java.util.Map;
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import org.junit.Test;
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public class KeyCheckUnitTest {
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@Test
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public void whenKeyIsPresent_thenContainsKeyReturnsTrue() {
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Map<String, String> map = Collections.singletonMap("key", "value");
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assertTrue(map.containsKey("key"));
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assertFalse(map.containsKey("missing"));
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}
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@Test
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public void whenKeyHasNullValue_thenGetStillWorks() {
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Map<String, String> map = Collections.singletonMap("nothing", null);
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assertTrue(map.containsKey("nothing"));
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assertNull(map.get("nothing"));
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}
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}
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@@ -0,0 +1,124 @@
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package com.baeldung.java.map;
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import static org.assertj.core.api.Assertions.assertThat;
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import java.util.ArrayList;
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import java.util.Collection;
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import java.util.HashMap;
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import java.util.List;
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import java.util.Map;
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import org.apache.commons.collections4.MultiMap;
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import org.apache.commons.collections4.MultiMapUtils;
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import org.apache.commons.collections4.MultiValuedMap;
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import org.apache.commons.collections4.map.MultiValueMap;
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import org.apache.commons.collections4.multimap.ArrayListValuedHashMap;
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import org.apache.commons.collections4.multimap.HashSetValuedHashMap;
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import org.junit.Test;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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import com.google.common.collect.ArrayListMultimap;
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import com.google.common.collect.LinkedHashMultimap;
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import com.google.common.collect.Multimap;
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import com.google.common.collect.TreeMultimap;
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public class MapMultipleValuesUnitTest {
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private static final Logger LOG = LoggerFactory.getLogger(MapMultipleValuesUnitTest.class);
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@Test
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public void givenHashMap_whenPuttingTwice_thenReturningFirstValue() {
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Map<String, String> map = new HashMap<>();
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assertThat(map.put("key1", "value1")).isEqualTo(null);
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assertThat(map.put("key1", "value2")).isEqualTo("value1");
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assertThat(map.get("key1")).isEqualTo("value2");
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}
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@Test
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public void givenCollectionAsValue_whenPuttingTwice_thenReturningCollection() {
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Map<String, List<String>> map = new HashMap<>();
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List<String> list = new ArrayList<>();
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map.put("key1", list);
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map.get("key1").add("value1");
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map.get("key1").add("value2");
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assertThat(map.get("key1").get(0)).isEqualTo("value1");
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assertThat(map.get("key1").get(1)).isEqualTo("value2");
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}
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@Test
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public void givenCollectionAsValueAndJava8_whenPuttingTwice_thenReturningCollection() {
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Map<String, List<String>> map = new HashMap<>();
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map.computeIfAbsent("key1", k -> new ArrayList<>()).add("value1");
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map.computeIfAbsent("key1", k -> new ArrayList<>()).add("value2");
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assertThat(map.get("key1").get(0)).isEqualTo("value1");
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assertThat(map.get("key1").get(1)).isEqualTo("value2");
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}
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@Test
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public void givenMultiValueMap_whenPuttingTwice_thenReturningValues() {
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MultiMap<String, String> map = new MultiValueMap<>();
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map.put("key1", "value1");
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map.put("key1", "value2");
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assertThat((Collection<String>) map.get("key1"))
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.contains("value1", "value2");
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}
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@Test
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public void givenArrayListValuedHashMap_whenPuttingDoubleValues_thenReturningAllValues() {
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MultiValuedMap<String, String> map = new ArrayListValuedHashMap<>();
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map.put("key1", "value1");
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map.put("key1", "value2");
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map.put("key1", "value2");
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assertThat((Collection<String>) map.get("key1"))
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.containsExactly("value1", "value2", "value2");
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}
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@Test
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public void givenHashSetValuedHashMap_whenPuttingTwiceTheSame_thenReturningOneValue() {
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MultiValuedMap<String, String> map = new HashSetValuedHashMap<>();
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map.put("key1", "value1");
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map.put("key1", "value1");
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assertThat((Collection<String>) map.get("key1"))
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.containsExactly("value1");
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}
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@Test(expected = UnsupportedOperationException.class)
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public void givenUnmodifiableMultiValuedMap_whenInserting_thenThrowingException() {
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MultiValuedMap<String, String> map = new ArrayListValuedHashMap<>();
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map.put("key1", "value1");
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map.put("key1", "value2");
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MultiValuedMap<String, String> immutableMap =
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MultiMapUtils.unmodifiableMultiValuedMap(map);
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immutableMap.put("key1", "value3");
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}
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@Test
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public void givenArrayListMultiMap_whenInserting_thenCorrectOutput() {
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Multimap<String, String> map = ArrayListMultimap.create();
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map.put("key1", "value2");
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map.put("key1", "value1");
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assertThat((Collection<String>) map.get("key1"))
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.containsExactly("value2", "value1");
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}
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@Test
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public void givenLinkedHashMultiMap_whenInserting_thenReturningValuesInInsertionOrder() {
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Multimap<String, String> map = LinkedHashMultimap.create();
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map.put("key1", "value3");
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map.put("key1", "value1");
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map.put("key1", "value2");
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assertThat((Collection<String>) map.get("key1"))
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.containsExactly("value3", "value1", "value2");
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}
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@Test
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public void givenTreeMultimap_whenInserting_thenReturningValuesInNaturalOrder() {
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Multimap<String, String> map = TreeMultimap.create();
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map.put("key1", "value3");
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map.put("key1", "value1");
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map.put("key1", "value2");
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assertThat((Collection<String>) map.get("key1"))
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.containsExactly("value1", "value2", "value3");
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}
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}
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@@ -0,0 +1,336 @@
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package com.baeldung.java.map;
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import org.junit.Test;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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import java.util.*;
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import java.util.Map.Entry;
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import static org.junit.Assert.*;
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public class MapUnitTest {
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private static final Logger LOG = LoggerFactory.getLogger(MapUnitTest.class);
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@Test
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public void givenHashMap_whenRetrievesKeyset_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put("name", "baeldung");
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map.put("type", "blog");
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Set<String> keys = map.keySet();
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assertEquals(2, keys.size());
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assertTrue(keys.contains("name"));
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assertTrue(keys.contains("type"));
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}
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@Test
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public void givenHashMap_whenRetrievesValues_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put("name", "baeldung");
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map.put("type", "blog");
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Collection<String> values = map.values();
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assertEquals(2, values.size());
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assertTrue(values.contains("baeldung"));
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assertTrue(values.contains("blog"));
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}
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@Test
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public void givenHashMap_whenRetrievesEntries_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put("name", "baeldung");
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map.put("type", "blog");
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Set<Entry<String, String>> entries = map.entrySet();
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assertEquals(2, entries.size());
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for (Entry<String, String> e : entries) {
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String key = e.getKey();
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String val = e.getValue();
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assertTrue(key.equals("name") || key.equals("type"));
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assertTrue(val.equals("baeldung") || val.equals("blog"));
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}
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}
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@Test
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public void givenKeySet_whenChangeReflectsInMap_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put("name", "baeldung");
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map.put("type", "blog");
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assertEquals(2, map.size());
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Set<String> keys = map.keySet();
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keys.remove("name");
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assertEquals(1, map.size());
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}
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@Test(expected = ConcurrentModificationException.class)
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public void givenIterator_whenFailsFastOnModification_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put("name", "baeldung");
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map.put("type", "blog");
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Set<String> keys = map.keySet();
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Iterator<String> it = keys.iterator();
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map.remove("type");
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while (it.hasNext()) {
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String key = it.next();
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}
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}
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public void givenIterator_whenRemoveWorks_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put("name", "baeldung");
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map.put("type", "blog");
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Set<String> keys = map.keySet();
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Iterator<String> it = keys.iterator();
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while (it.hasNext()) {
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it.next();
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it.remove();
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}
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assertEquals(0, map.size());
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}
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@Test
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public void whenHashCodeIsCalledOnPut_thenCorrect() {
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MyKey key = new MyKey(1, "name");
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Map<MyKey, String> map = new HashMap<>();
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map.put(key, "val");
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}
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@Test
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public void whenHashCodeIsCalledOnGet_thenCorrect() {
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MyKey key = new MyKey(1, "name");
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Map<MyKey, String> map = new HashMap<>();
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map.put(key, "val");
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map.get(key);
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}
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@Test
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public void whenGetWorks_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put("key", "val");
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String val = map.get("key");
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assertEquals("val", val);
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}
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@Test
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public void givenNewKey_whenPutReturnsNull_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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String rtnVal = map.put("key1", "val1");
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assertNull(rtnVal);
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}
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@Test
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public void givenUnmappedKey_whenGetReturnsNull_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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String rtnVal = map.get("key1");
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assertNull(rtnVal);
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}
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@Test
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public void givenNullVal_whenPutReturnsNull_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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String rtnVal = map.put("key1", null);
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assertNull(rtnVal);
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}
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@Test
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public void givenNullKeyAndVal_whenAccepts_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put(null, null);
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}
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@Test
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public void givenNullVal_whenRetrieves_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put("key", null);
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String val = map.get("key");
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assertNull(val);
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}
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@Test
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public void whenContainsDistinguishesNullValues_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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String val1 = map.get("key");
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boolean valPresent = map.containsKey("key");
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assertNull(val1);
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assertFalse(valPresent);
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map.put("key", null);
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String val = map.get("key");
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valPresent = map.containsKey("key");
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assertNull(val);
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assertTrue(valPresent);
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}
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@Test
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public void whenPutReturnsPrevValue_thenCorrect() {
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Map<String, String> map = new HashMap<>();
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map.put("key1", "val1");
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String rtnVal = map.put("key1", "val2");
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assertEquals("val1", rtnVal);
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}
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@Test
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public void whenCallsEqualsOnCollision_thenCorrect() {
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HashMap<MyKey, String> map = new HashMap<>();
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MyKey k1 = new MyKey(1, "firstKey");
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MyKey k2 = new MyKey(2, "secondKey");
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MyKey k3 = new MyKey(2, "thirdKey");
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LOG.debug("storing value for k1");
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map.put(k1, "firstValue");
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LOG.debug("storing value for k2");
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map.put(k2, "secondValue");
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LOG.debug("storing value for k3");
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map.put(k3, "thirdValue");
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LOG.debug("retrieving value for k1");
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String v1 = map.get(k1);
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LOG.debug("retrieving value for k2");
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String v2 = map.get(k2);
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LOG.debug("retrieving value for k3");
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String v3 = map.get(k3);
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assertEquals("firstValue", v1);
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assertEquals("secondValue", v2);
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assertEquals("thirdValue", v3);
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}
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@Test
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public void givenLinkedHashMap_whenGetsOrderedKeyset_thenCorrect() {
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LinkedHashMap<Integer, String> map = new LinkedHashMap<>();
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map.put(1, null);
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map.put(2, null);
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map.put(3, null);
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map.put(4, null);
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map.put(5, null);
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Set<Integer> keys = map.keySet();
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Integer[] arr = keys.toArray(new Integer[0]);
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for (int i = 0; i < arr.length; i++) {
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assertEquals(new Integer(i + 1), arr[i]);
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}
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}
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@Test
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public void givenLinkedHashMap_whenAccessOrderWorks_thenCorrect() {
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LinkedHashMap<Integer, String> map = new LinkedHashMap<>(16, .75f, true);
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map.put(1, null);
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map.put(2, null);
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map.put(3, null);
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map.put(4, null);
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map.put(5, null);
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Set<Integer> keys = map.keySet();
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assertEquals("[1, 2, 3, 4, 5]", keys.toString());
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map.get(4);
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assertEquals("[1, 2, 3, 5, 4]", keys.toString());
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map.get(1);
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assertEquals("[2, 3, 5, 4, 1]", keys.toString());
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map.get(3);
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assertEquals("[2, 5, 4, 1, 3]", keys.toString());
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}
|
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@Test
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public void givenLinkedHashMap_whenRemovesEldestEntry_thenCorrect() {
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LinkedHashMap<Integer, String> map = new MyLinkedHashMap<>(16, .75f, true);
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map.put(1, null);
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map.put(2, null);
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map.put(3, null);
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map.put(4, null);
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map.put(5, null);
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Set<Integer> keys = map.keySet();
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assertEquals("[1, 2, 3, 4, 5]", keys.toString());
|
||||
map.put(6, null);
|
||||
assertEquals("[2, 3, 4, 5, 6]", keys.toString());
|
||||
map.put(7, null);
|
||||
assertEquals("[3, 4, 5, 6, 7]", keys.toString());
|
||||
map.put(8, null);
|
||||
assertEquals("[4, 5, 6, 7, 8]", keys.toString());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenTreeMap_whenOrdersEntriesNaturally_thenCorrect() {
|
||||
TreeMap<Integer, String> map = new TreeMap<>();
|
||||
map.put(3, "val");
|
||||
map.put(2, "val");
|
||||
map.put(1, "val");
|
||||
map.put(5, "val");
|
||||
map.put(4, "val");
|
||||
assertEquals("[1, 2, 3, 4, 5]", map.keySet().toString());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenTreeMap_whenOrdersEntriesNaturally_thenCorrect2() {
|
||||
TreeMap<String, String> map = new TreeMap<>();
|
||||
map.put("c", "val");
|
||||
map.put("b", "val");
|
||||
map.put("a", "val");
|
||||
map.put("e", "val");
|
||||
map.put("d", "val");
|
||||
|
||||
assertEquals("[a, b, c, d, e]", map.keySet().toString());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenTreeMap_whenOrdersEntriesByComparator_thenCorrect() {
|
||||
TreeMap<Integer, String> map = new TreeMap<>(Comparator.reverseOrder());
|
||||
map.put(3, "val");
|
||||
map.put(2, "val");
|
||||
map.put(1, "val");
|
||||
map.put(5, "val");
|
||||
map.put(4, "val");
|
||||
|
||||
assertEquals("[5, 4, 3, 2, 1]", map.keySet().toString());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenTreeMap_whenPerformsQueries_thenCorrect() {
|
||||
TreeMap<Integer, String> map = new TreeMap<>();
|
||||
map.put(3, "val");
|
||||
map.put(2, "val");
|
||||
map.put(1, "val");
|
||||
map.put(5, "val");
|
||||
map.put(4, "val");
|
||||
|
||||
Integer highestKey = map.lastKey();
|
||||
Integer lowestKey = map.firstKey();
|
||||
Set<Integer> keysLessThan3 = map.headMap(3).keySet();
|
||||
Set<Integer> keysGreaterThanEqTo3 = map.tailMap(3).keySet();
|
||||
|
||||
assertEquals(new Integer(5), highestKey);
|
||||
assertEquals(new Integer(1), lowestKey);
|
||||
assertEquals("[1, 2]", keysLessThan3.toString());
|
||||
assertEquals("[3, 4, 5]", keysGreaterThanEqTo3.toString());
|
||||
}
|
||||
|
||||
}
|
||||
@@ -0,0 +1,104 @@
|
||||
/**
|
||||
*
|
||||
*/
|
||||
package com.baeldung.java.map;
|
||||
|
||||
import static org.junit.Assert.assertEquals;
|
||||
|
||||
import java.util.Arrays;
|
||||
import java.util.HashMap;
|
||||
import java.util.HashSet;
|
||||
import java.util.Map;
|
||||
import java.util.stream.Collectors;
|
||||
|
||||
import org.apache.commons.collections4.BidiMap;
|
||||
import org.apache.commons.collections4.bidimap.DualHashBidiMap;
|
||||
import org.junit.Test;
|
||||
|
||||
import com.google.common.collect.HashBiMap;
|
||||
|
||||
/**
|
||||
* @author swpraman
|
||||
*
|
||||
*/
|
||||
public class MapUtilUnitTest {
|
||||
|
||||
|
||||
@Test
|
||||
public void whenUsingImperativeWayForSingleKey_shouldReturnSingleKey() {
|
||||
Map<String, String> capitalCountryMap = new HashMap<>();
|
||||
capitalCountryMap.put("Tokyo", "Japan");
|
||||
capitalCountryMap.put("New Delhi", "India");
|
||||
assertEquals("New Delhi", MapUtil.getKey(capitalCountryMap, "India"));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenUsingImperativeWayForAllKeys_shouldReturnAllKeys() {
|
||||
Map<String, String> capitalCountryMap = new HashMap<>();
|
||||
capitalCountryMap.put("Tokyo", "Japan");
|
||||
capitalCountryMap.put("Berlin", "Germany");
|
||||
capitalCountryMap.put("Cape Town", "South Africa");
|
||||
capitalCountryMap.put("Pretoria", "South Africa");
|
||||
capitalCountryMap.put("Bloemfontein", "South Africa");
|
||||
|
||||
assertEquals(new HashSet<String>(Arrays.asList(
|
||||
new String[] {"Cape Town", "Pretoria", "Bloemfontein"})),
|
||||
MapUtil.getKeys(capitalCountryMap, "South Africa"));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenUsingFunctionalWayForSingleKey_shouldReturnSingleKey() {
|
||||
Map<String, String> capitalCountryMap = new HashMap<>();
|
||||
capitalCountryMap.put("Tokyo", "Japan");
|
||||
capitalCountryMap.put("Berlin", "Germany");
|
||||
assertEquals("Berlin", MapUtil.keys(capitalCountryMap, "Germany").findFirst().get());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenUsingFunctionalWayForAllKeys_shouldReturnAllKeys() {
|
||||
Map<String, String> capitalCountryMap = new HashMap<>();
|
||||
capitalCountryMap.put("Tokyo", "Japan");
|
||||
capitalCountryMap.put("Berlin", "Germany");
|
||||
capitalCountryMap.put("Cape Town", "South Africa");
|
||||
capitalCountryMap.put("Pretoria", "South Africa");
|
||||
capitalCountryMap.put("Bloemfontein", "South Africa");
|
||||
assertEquals(new HashSet<String>(Arrays.asList(
|
||||
new String[] {"Cape Town", "Pretoria", "Bloemfontein"})),
|
||||
MapUtil.keys(capitalCountryMap, "South Africa").collect(Collectors.toSet()));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenUsingBidiMap_shouldReturnKey() {
|
||||
BidiMap<String, String> capitalCountryMap = new DualHashBidiMap<String, String>();
|
||||
capitalCountryMap.put("Berlin", "Germany");
|
||||
capitalCountryMap.put("Cape Town", "South Africa");
|
||||
assertEquals("Berlin", capitalCountryMap.getKey("Germany"));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenUsingBidiMapAddDuplicateValue_shouldRemoveOldEntry() {
|
||||
BidiMap<String, String> capitalCountryMap = new DualHashBidiMap<String, String>();
|
||||
capitalCountryMap.put("Berlin", "Germany");
|
||||
capitalCountryMap.put("Cape Town", "South Africa");
|
||||
capitalCountryMap.put("Pretoria", "South Africa");
|
||||
assertEquals("Pretoria", capitalCountryMap.getKey("South Africa"));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenUsingBiMap_shouldReturnKey() {
|
||||
HashBiMap<String, String> capitalCountryMap = HashBiMap.create();
|
||||
capitalCountryMap.put("Berlin", "Germany");
|
||||
capitalCountryMap.put("Cape Town", "South Africa");
|
||||
assertEquals("Berlin", capitalCountryMap.inverse().get("Germany"));
|
||||
}
|
||||
|
||||
@Test(expected=IllegalArgumentException.class)
|
||||
public void whenUsingBiMapAddDuplicateValue_shouldThrowException() {
|
||||
HashBiMap<String, String> capitalCountryMap = HashBiMap.create();
|
||||
capitalCountryMap.put("Berlin", "Germany");
|
||||
capitalCountryMap.put("Cape Town", "South Africa");
|
||||
capitalCountryMap.put("Pretoria", "South Africa");
|
||||
assertEquals("Berlin", capitalCountryMap.inverse().get("Germany"));
|
||||
}
|
||||
|
||||
}
|
||||
@@ -0,0 +1,27 @@
|
||||
package com.baeldung.java.map.initialize;
|
||||
|
||||
import static org.junit.Assert.assertEquals;
|
||||
|
||||
import java.util.Map;
|
||||
|
||||
import org.junit.Test;
|
||||
|
||||
public class MapInitializerUnitTest {
|
||||
|
||||
@Test
|
||||
public void givenStaticMap_whenUpdated_thenCorrect() {
|
||||
|
||||
MapInitializer.articleMapOne.put("NewArticle1", "Convert array to List");
|
||||
|
||||
assertEquals(MapInitializer.articleMapOne.get("NewArticle1"), "Convert array to List");
|
||||
|
||||
}
|
||||
|
||||
@Test(expected=UnsupportedOperationException.class)
|
||||
public void givenSingleTonMap_whenEntriesAdded_throwsException() {
|
||||
|
||||
Map<String, String> map = MapInitializer.createSingletonMap();
|
||||
map.put("username2", "password2");
|
||||
}
|
||||
|
||||
}
|
||||
@@ -0,0 +1,59 @@
|
||||
package com.baeldung.map.util;
|
||||
|
||||
|
||||
|
||||
import static org.junit.Assert.assertEquals;
|
||||
|
||||
import java.util.HashMap;
|
||||
import java.util.Map;
|
||||
|
||||
import org.junit.Before;
|
||||
import org.junit.Test;
|
||||
|
||||
public class MapMaxUnitTest {
|
||||
|
||||
Map<Integer, Integer> map = null;
|
||||
MapMax mapMax = null;
|
||||
|
||||
|
||||
@Before
|
||||
public void setupTestData() {
|
||||
map = new HashMap<Integer, Integer>();
|
||||
map.put(23, 12);
|
||||
map.put(46, 24);
|
||||
map.put(27, 38);
|
||||
mapMax = new MapMax();
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenMap_whenIterated_thenReturnMaxValue() {
|
||||
assertEquals(new Integer(38), mapMax.maxUsingIteration(map));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenMap_whenUsingCollectionsMax_thenReturnMaxValue() {
|
||||
assertEquals(new Integer(38), mapMax.maxUsingCollectionsMax(map));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenMap_whenUsingCollectionsMaxAndLambda_thenReturnMaxValue() {
|
||||
assertEquals(new Integer(38), mapMax.maxUsingCollectionsMaxAndLambda(map));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenMap_whenUsingCollectionsMaxAndMethodReference_thenReturnMaxValue() {
|
||||
assertEquals(new Integer(38), mapMax.maxUsingCollectionsMaxAndMethodReference(map));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenMap_whenUsingStreamAndLambda_thenReturnMaxValue() {
|
||||
assertEquals(new Integer(38), mapMax.maxUsingStreamAndLambda(map));
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenMap_whenUsingStreamAndMethodReference_thenReturnMaxValue() {
|
||||
assertEquals(new Integer(38), mapMax.maxUsingStreamAndMethodReference (map));
|
||||
}
|
||||
|
||||
|
||||
}
|
||||
@@ -0,0 +1,72 @@
|
||||
package com.baeldung.weakhashmap;
|
||||
|
||||
|
||||
import org.junit.Test;
|
||||
|
||||
import java.util.WeakHashMap;
|
||||
import java.util.concurrent.TimeUnit;
|
||||
|
||||
import static com.jayway.awaitility.Awaitility.await;
|
||||
import static org.junit.Assert.assertTrue;
|
||||
|
||||
public class WeakHashMapUnitTest {
|
||||
|
||||
@Test
|
||||
public void givenWeakHashMap_whenCacheValueThatHasNoReferenceToIt_GCShouldReclaimThatObject() {
|
||||
//given
|
||||
WeakHashMap<UniqueImageName, BigImage> map = new WeakHashMap<>();
|
||||
BigImage bigImage = new BigImage("image_id");
|
||||
UniqueImageName imageName = new UniqueImageName("name_of_big_image");
|
||||
|
||||
map.put(imageName, bigImage);
|
||||
assertTrue(map.containsKey(imageName));
|
||||
|
||||
//when big image key is not reference anywhere
|
||||
imageName = null;
|
||||
System.gc();
|
||||
|
||||
//then GC will finally reclaim that object
|
||||
await().atMost(10, TimeUnit.SECONDS).until(map::isEmpty);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void givenWeakHashMap_whenCacheValueThatHasNoReferenceToIt_GCShouldReclaimThatObjectButLeaveReferencedObject() {
|
||||
//given
|
||||
WeakHashMap<UniqueImageName, BigImage> map = new WeakHashMap<>();
|
||||
BigImage bigImageFirst = new BigImage("foo");
|
||||
UniqueImageName imageNameFirst = new UniqueImageName("name_of_big_image");
|
||||
|
||||
BigImage bigImageSecond = new BigImage("foo_2");
|
||||
UniqueImageName imageNameSecond = new UniqueImageName("name_of_big_image_2");
|
||||
|
||||
map.put(imageNameFirst, bigImageFirst);
|
||||
map.put(imageNameSecond, bigImageSecond);
|
||||
assertTrue(map.containsKey(imageNameFirst));
|
||||
assertTrue(map.containsKey(imageNameSecond));
|
||||
|
||||
//when
|
||||
imageNameFirst = null;
|
||||
System.gc();
|
||||
|
||||
//then
|
||||
await().atMost(10, TimeUnit.SECONDS).until(() -> map.size() == 1);
|
||||
await().atMost(10, TimeUnit.SECONDS).until(() -> map.containsKey(imageNameSecond));
|
||||
}
|
||||
|
||||
|
||||
class BigImage {
|
||||
public final String imageId;
|
||||
|
||||
BigImage(String imageId) {
|
||||
this.imageId = imageId;
|
||||
}
|
||||
}
|
||||
|
||||
class UniqueImageName {
|
||||
public final String imageName;
|
||||
|
||||
UniqueImageName(String imageName) {
|
||||
this.imageName = imageName;
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user