Merge pull request #10643 from mdhtr/mdhtr/BAEL-4179_primitive_to_object_array

BAEL-4179 Cast primitive type array into object array in java

core-java-modules/core-java-lang-oop-types-2/README.md

@@ -0,0 +1,7 @@
+## Core Java Lang OOP - Types
+
+This module contains articles about types in Java
+
+### Relevant Articles: 
+
+-

core-java-modules/core-java-lang-oop-types-2/pom.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>core-java-modules</artifactId>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>core-java-lang-oop-types-2</artifactId>
+    <packaging>jar</packaging>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+    </dependencies>
+</project>

core-java-modules/core-java-lang-oop-types-2/src/test/java/com/baeldung/conversions/PrimitiveToObjectArrayUnitTest.java

@@ -0,0 +1,81 @@
+package com.baeldung.conversions;
+
+import org.apache.commons.lang3.ArrayUtils;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class PrimitiveToObjectArrayUnitTest {
+
+    @Test
+    void givenUsingIteration_whenConvertingToObjects_thenSuccess() {
+        int[] input = new int[] { 0, 1, 2, 3, 4 };
+        Integer[] expected = new Integer[] { 0, 1, 2, 3, 4 };
+
+        Integer[] output = new Integer[input.length];
+        for (int i = 0; i < input.length; i++) {
+            output[i] = input[i];
+        }
+
+        assertArrayEquals(expected, output);
+    }
+
+    @Test
+    void givenUsingIteration_whenConvertingToPrimitives_thenSuccess() {
+        Integer[] input = new Integer[] { 0, 1, 2, 3, 4 };
+        int[] expected = new int[] { 0, 1, 2, 3, 4 };
+
+        int[] output = new int[input.length];
+        for (int i = 0; i < input.length; i++) {
+            output[i] = input[i];
+        }
+
+        assertArrayEquals(expected, output);
+    }
+
+    @Test
+    void givenUsingStreams_whenConvertingToObjects_thenSuccess() {
+        int[] input = new int[] { 0, 1, 2, 3, 4 };
+        Integer[] expected = new Integer[] { 0, 1, 2, 3, 4 };
+
+        Integer[] output = Arrays.stream(input)
+            .boxed()
+            .toArray(Integer[]::new);
+
+        assertArrayEquals(expected, output);
+    }
+
+    @Test
+    void givenUsingStreams_whenConvertingToPrimitives_thenSuccess() {
+        Integer[] input = new Integer[] { 0, 1, 2, 3, 4 };
+        int[] expected = new int[] { 0, 1, 2, 3, 4 };
+
+        int[] output = Arrays.stream(input)
+            .mapToInt(Integer::intValue)
+            .toArray();
+
+        assertArrayEquals(expected, output);
+    }
+
+    @Test
+    void givenUsingApacheCommons_whenConvertingToObjects_thenSuccess() {
+        int[] input = new int[] { 0, 1, 2, 3, 4 };
+        Integer[] expected = new Integer[] { 0, 1, 2, 3, 4 };
+
+        Integer[] output = ArrayUtils.toObject(input);
+
+        assertArrayEquals(expected, output);
+    }
+
+    @Test
+    void givenUsingApacheCommons_whenConvertingToPrimitives_thenSuccess() {
+        Integer[] input = new Integer[] { 0, 1, 2, 3, 4 };
+        int[] expected = new int[] { 0, 1, 2, 3, 4 };
+
+        int[] output = ArrayUtils.toPrimitive(input);
+
+        assertArrayEquals(expected, output);
+    }
+}

core-java-modules/pom.xml

@@ -91,6 +91,7 @@
         <module>core-java-lang-oop-generics</module>
         <module>core-java-lang-oop-modifiers</module>
         <module>core-java-lang-oop-types</module>
+        <module>core-java-lang-oop-types-2</module>
         <module>core-java-lang-oop-inheritance</module>
         <module>core-java-lang-oop-methods</module>
         <module>core-java-lang-oop-others</module>