Java 从一个 List 中删除所有重复的元素： https://www.ossez.com/t/java-list/13942

core-java-modules/core-java-collections-list/src/test/java/com/ossez/collections/JavaCollectionCleanupDuplicatesTest.java

@@ -0,0 +1,64 @@
+package com.ossez.collections;
+
+import com.google.common.base.Predicates;
+import com.google.common.collect.Iterables;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import org.apache.commons.collections4.CollectionUtils;
+import org.apache.commons.collections4.PredicateUtils;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.TestInstance;
+
+import java.util.*;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.*;
+
+/**
+ * Test for list Clean up
+ *
+ * <p><a href="https://www.ossez.com/t/java-list/13942">https://www.ossez.com/t/java-list/13942</a></p>
+ *
+ * @author YuCheng
+ */
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+public class JavaCollectionCleanupDuplicatesTest {
+
+    // TESTS - REMOVE DUPLICATES
+
+    @Test
+    public void givenListContainsDuplicates_whenRemovingDuplicatesWithPlainJava_thenCorrect() {
+        final List<Integer> listWithDuplicates = Lists.newArrayList(5, 0, 3, 1, 2, 3, 0, 0);
+        final List<Integer> listWithoutDuplicates = new ArrayList<>(new HashSet<>(listWithDuplicates));
+
+        assertThat(listWithoutDuplicates, hasSize(5));
+        assertThat(listWithoutDuplicates, containsInAnyOrder(5, 0, 3, 1, 2));
+    }
+
+    @Test
+    public void givenListContainsDuplicates_whenRemovingDuplicatesPreservingOrderWithPlainJava_thenCorrect() {
+        final List<Integer> listWithDuplicates = Lists.newArrayList(5, 0, 3, 1, 2, 3, 0, 0);
+        final List<Integer> listWithoutDuplicates = new ArrayList<>(new LinkedHashSet<>(listWithDuplicates));
+
+        assertThat(listWithoutDuplicates, hasSize(5));
+        assertThat(listWithoutDuplicates, containsInRelativeOrder(5, 0, 3, 1, 2));
+    }
+
+    @Test
+    public void givenListContainsDuplicates_whenRemovingDuplicatesWithGuava_thenCorrect() {
+        final List<Integer> listWithDuplicates = Lists.newArrayList(5, 0, 3, 1, 2, 3, 0, 0);
+        final List<Integer> listWithoutDuplicates = Lists.newArrayList(Sets.newHashSet(listWithDuplicates));
+
+        assertThat(listWithoutDuplicates, hasSize(5));
+        assertThat(listWithoutDuplicates, containsInAnyOrder(5, 0, 3, 1, 2));
+    }
+
+    @Test
+    public void givenListContainsDuplicates_whenRemovingDuplicatesPreservingOrderWithGuava_thenCorrect() {
+        final List<Integer> listWithDuplicates = Lists.newArrayList(5, 0, 3, 1, 2, 3, 0, 0);
+        final List<Integer> listWithoutDuplicates = Lists.newArrayList(Sets.newLinkedHashSet(listWithDuplicates));
+
+        assertThat(listWithoutDuplicates, hasSize(5));
+        assertThat(listWithoutDuplicates, containsInRelativeOrder(5, 0, 3, 1, 2));
+    }
+}

core-java-modules/core-java-collections-list/src/test/java/com/ossez/collections/JavaCollectionCleanupUnitTest.java

@@ -71,7 +71,7 @@ public class JavaCollectionCleanupUnitTest {
         assertThat(list, hasSize(3));
     }
 
-    // tests - remove duplicates
+    // TESTS - REMOVE DUPLICATES
 
     @Test
     public void givenListContainsDuplicates_whenRemovingDuplicatesWithPlainJava_thenCorrect() {

core-java-modules/core-java-collections-list/src/test/java/com/ossez/java8/Java8CollectionCleanupUnitTest.java

@@ -2,15 +2,24 @@ package com.ossez.java8;
 
 import com.google.common.collect.Lists;
 import org.junit.Test;
+import org.junit.jupiter.api.TestInstance;
 
 import java.util.List;
 import java.util.Objects;
 import java.util.stream.Collectors;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsInAnyOrder;
 import static org.hamcrest.Matchers.hasSize;
-import static org.junit.Assert.assertThat;
 
+/**
+ * Test for list Clean up
+ *
+ * <p><a href="https://www.ossez.com/t/java-list/13942">https://www.ossez.com/t/java-list/13942</a></p>
+ *
+ * @author YuCheng
+ */
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
 public class Java8CollectionCleanupUnitTest {
 
     // tests -