From 7ec1db1be2c508793f16a6a317bf5d2eab49343a Mon Sep 17 00:00:00 2001 From: juan Date: Tue, 15 Aug 2017 23:48:47 -0300 Subject: [PATCH] Sample code for article - JIRA: (BAEL-1079) Java 8 Streams distinctBy() some property(+ external tools) --- libraries/pom.xml | 23 ++++--- .../distinct/DistinctWithJavaFunction.java | 15 +++++ .../java/com/baeldung/distinct/Person.java | 65 +++++++++++++++++++ ...istinctWithEclipseCollectionsUnitTest.java | 32 +++++++++ .../DistinctWithJavaFunctionUnitTest.java | 44 +++++++++++++ .../DistinctWithStreamexUnitTest.java | 36 ++++++++++ .../distinct/DistinctWithVavrUnitTest.java | 34 ++++++++++ .../distinct/PersonDataGenerator.java | 19 ++++++ 8 files changed, 260 insertions(+), 8 deletions(-) create mode 100644 libraries/src/main/java/com/baeldung/distinct/DistinctWithJavaFunction.java create mode 100644 libraries/src/main/java/com/baeldung/distinct/Person.java create mode 100644 libraries/src/test/java/com/baeldung/distinct/DistinctWithEclipseCollectionsUnitTest.java create mode 100644 libraries/src/test/java/com/baeldung/distinct/DistinctWithJavaFunctionUnitTest.java create mode 100644 libraries/src/test/java/com/baeldung/distinct/DistinctWithStreamexUnitTest.java create mode 100644 libraries/src/test/java/com/baeldung/distinct/DistinctWithVavrUnitTest.java create mode 100644 libraries/src/test/java/com/baeldung/distinct/PersonDataGenerator.java diff --git a/libraries/pom.xml b/libraries/pom.xml index a16a4de59d..70ee008925 100644 --- a/libraries/pom.xml +++ b/libraries/pom.xml @@ -186,11 +186,11 @@ rome ${rome.version} - - io.specto - hoverfly-java - 0.8.0 - + + io.specto + hoverfly-java + 0.8.0 + org.apache.httpcomponents httpclient @@ -380,7 +380,7 @@ one.util streamex - 0.6.5 + ${streamex.version} org.jooq @@ -467,11 +467,16 @@ noexception 1.1.0 - + org.eclipse.collections eclipse-collections ${eclipse-collections.version} + + io.vavr + vavr + ${vavr.version} + 0.7.0 @@ -513,6 +518,8 @@ 1.7.1 2.1.2 1.0 - 8.2.0 + 8.2.0 + 0.6.5 + 0.9.0 \ No newline at end of file diff --git a/libraries/src/main/java/com/baeldung/distinct/DistinctWithJavaFunction.java b/libraries/src/main/java/com/baeldung/distinct/DistinctWithJavaFunction.java new file mode 100644 index 0000000000..0d08c94b47 --- /dev/null +++ b/libraries/src/main/java/com/baeldung/distinct/DistinctWithJavaFunction.java @@ -0,0 +1,15 @@ +package com.baeldung.distinct; + +import java.util.Map; +import java.util.concurrent.ConcurrentHashMap; +import java.util.function.Function; +import java.util.function.Predicate; + +public class DistinctWithJavaFunction { + + public static Predicate distinctByKey(Function keyExtractor) { + Map seen = new ConcurrentHashMap<>(); + return t -> seen.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null; + } + +} diff --git a/libraries/src/main/java/com/baeldung/distinct/Person.java b/libraries/src/main/java/com/baeldung/distinct/Person.java new file mode 100644 index 0000000000..8a2a5f7a45 --- /dev/null +++ b/libraries/src/main/java/com/baeldung/distinct/Person.java @@ -0,0 +1,65 @@ +package com.baeldung.distinct; + +public class Person { + int age; + String name; + String email; + + public Person(int age, String name, String email) { + super(); + this.age = age; + this.name = name; + this.email = email; + } + + public int getAge() { + return age; + } + + public String getName() { + return name; + } + + public String getEmail() { + return email; + } + + @Override + public String toString() { + StringBuilder builder = new StringBuilder(); + builder.append("Person [age="); + builder.append(age); + builder.append(", name="); + builder.append(name); + builder.append(", email="); + builder.append(email); + builder.append("]"); + return builder.toString(); + } + + @Override + public int hashCode() { + final int prime = 31; + int result = 1; + result = prime * result + ((email == null) ? 0 : email.hashCode()); + return result; + } + + @Override + public boolean equals(Object obj) { + if (this == obj) + return true; + if (obj == null) + return false; + if (getClass() != obj.getClass()) + return false; + Person other = (Person) obj; + if (email == null) { + if (other.email != null) + return false; + } else if (!email.equals(other.email)) + return false; + return true; + } + +} diff --git a/libraries/src/test/java/com/baeldung/distinct/DistinctWithEclipseCollectionsUnitTest.java b/libraries/src/test/java/com/baeldung/distinct/DistinctWithEclipseCollectionsUnitTest.java new file mode 100644 index 0000000000..dffde3917c --- /dev/null +++ b/libraries/src/test/java/com/baeldung/distinct/DistinctWithEclipseCollectionsUnitTest.java @@ -0,0 +1,32 @@ +package com.baeldung.distinct; + +import static org.junit.Assert.assertTrue; + +import java.util.List; + +import org.eclipse.collections.impl.block.factory.HashingStrategies; +import org.eclipse.collections.impl.utility.ListIterate; +import org.junit.Before; +import org.junit.Test; + +public class DistinctWithEclipseCollectionsUnitTest { + List personList; + + @Before + public void init() { + personList = PersonDataGenerator.getPersonListWithFakeValues(); + } + + @Test + public void whenFilterListByName_thenSizeShouldBe4() { + List personListFiltered = ListIterate.distinct(personList, HashingStrategies.fromFunction(Person::getName)); + assertTrue(personListFiltered.size() == 4); + } + + @Test + public void whenFilterListByAge_thenSizeShouldBe2() { + List personListFiltered = ListIterate.distinct(personList, HashingStrategies.fromIntFunction(Person::getAge)); + assertTrue(personListFiltered.size() == 2); + } + +} diff --git a/libraries/src/test/java/com/baeldung/distinct/DistinctWithJavaFunctionUnitTest.java b/libraries/src/test/java/com/baeldung/distinct/DistinctWithJavaFunctionUnitTest.java new file mode 100644 index 0000000000..68775fac66 --- /dev/null +++ b/libraries/src/test/java/com/baeldung/distinct/DistinctWithJavaFunctionUnitTest.java @@ -0,0 +1,44 @@ +package com.baeldung.distinct; + +import static org.junit.Assert.assertTrue; +import static com.baeldung.distinct.DistinctWithJavaFunction.distinctByKey; + +import java.util.List; +import java.util.stream.Collectors; + +import org.junit.Before; +import org.junit.Test; + +public class DistinctWithJavaFunctionUnitTest { + List personList; + + @Before + public void init() { + personList = PersonDataGenerator.getPersonListWithFakeValues(); + } + + @Test + public void whenFilterListByName_thenSizeShouldBe4() { + List personListFiltered = personList.stream() + .filter(distinctByKey(p -> p.getName())) + .collect(Collectors.toList()); + assertTrue(personListFiltered.size() == 4); + } + + @Test + public void whenFilterListByAge_thenSizeShouldBe2() { + List personListFiltered = personList.stream() + .filter(distinctByKey(p -> p.getAge())) + .collect(Collectors.toList()); + assertTrue(personListFiltered.size() == 2); + } + + @Test + public void whenFilterListWithDefaultDistinct_thenSizeShouldBe5() { + List personListFiltered = personList.stream() + .distinct() + .collect(Collectors.toList()); + assertTrue(personListFiltered.size() == 5); + } + +} diff --git a/libraries/src/test/java/com/baeldung/distinct/DistinctWithStreamexUnitTest.java b/libraries/src/test/java/com/baeldung/distinct/DistinctWithStreamexUnitTest.java new file mode 100644 index 0000000000..f50c76a486 --- /dev/null +++ b/libraries/src/test/java/com/baeldung/distinct/DistinctWithStreamexUnitTest.java @@ -0,0 +1,36 @@ +package com.baeldung.distinct; + +import static org.junit.Assert.assertTrue; + +import java.util.List; + +import org.junit.Before; +import org.junit.Test; + +import one.util.streamex.StreamEx; + +public class DistinctWithStreamexUnitTest { + List personList; + + @Before + public void init() { + personList = PersonDataGenerator.getPersonListWithFakeValues(); + } + + @Test + public void whenFilterListByName_thenSizeShouldBe4() { + List personListFiltered = StreamEx.of(personList) + .distinct(Person::getName) + .toList(); + assertTrue(personListFiltered.size() == 4); + } + + @Test + public void whenFilterListByAge_thenSizeShouldBe2() { + List personListFiltered = StreamEx.of(personList) + .distinct(Person::getAge) + .toList(); + assertTrue(personListFiltered.size() == 2); + } + +} diff --git a/libraries/src/test/java/com/baeldung/distinct/DistinctWithVavrUnitTest.java b/libraries/src/test/java/com/baeldung/distinct/DistinctWithVavrUnitTest.java new file mode 100644 index 0000000000..b4025cd313 --- /dev/null +++ b/libraries/src/test/java/com/baeldung/distinct/DistinctWithVavrUnitTest.java @@ -0,0 +1,34 @@ +package com.baeldung.distinct; + +import static org.junit.Assert.assertTrue; + +import java.util.List; + +import org.junit.Before; +import org.junit.Test; + +public class DistinctWithVavrUnitTest { + List personList; + + @Before + public void init() { + personList = PersonDataGenerator.getPersonListWithFakeValues(); + } + + @Test + public void whenFilterListByName_thenSizeShouldBe4() { + List personListFiltered = io.vavr.collection.List.ofAll(personList) + .distinctBy(Person::getName) + .toJavaList(); + assertTrue(personListFiltered.size() == 4); + } + + @Test + public void whenFilterListByAge_thenSizeShouldBe2() { + List personListFiltered = io.vavr.collection.List.ofAll(personList) + .distinctBy(Person::getAge) + .toJavaList(); + assertTrue(personListFiltered.size() == 2); + } + +} diff --git a/libraries/src/test/java/com/baeldung/distinct/PersonDataGenerator.java b/libraries/src/test/java/com/baeldung/distinct/PersonDataGenerator.java new file mode 100644 index 0000000000..51590005ac --- /dev/null +++ b/libraries/src/test/java/com/baeldung/distinct/PersonDataGenerator.java @@ -0,0 +1,19 @@ +package com.baeldung.distinct; + +import java.util.Arrays; +import java.util.List; + +public class PersonDataGenerator { + + public static List getPersonListWithFakeValues() { + // @formatter:off + return Arrays.asList( + new Person(20, "Jhon", "jhon@test.com"), + new Person(20, "Jhon", "jhon1@test.com"), + new Person(20, "Jhon", "jhon2@test.com"), + new Person(21, "Tom", "Tom@test.com"), + new Person(21, "Mark", "Mark@test.com"), + new Person(20, "Julia", "jhon@test.com")); + // @formatter:on + } +}