[BAEL-6297_boolean-to-str] convert boolean to java article (#13729)

* [BAEL-6297_boolean-to-str] convert boolean to java article

* [BAEL-6297_boolean-to-str] using Boolean.FALSE instead of false for the Boolean variable

* [BAEL-6297_boolean-to-str] rename test methods

core-java-modules/core-java-booleans/README.md

@@ -0,0 +1,5 @@
+## Core Java Booleans
+
+This module contains articles about Java Booleans.
+
+### Relevant Articles: 

core-java-modules/core-java-booleans/pom.xml

@@ -0,0 +1,16 @@
+<?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">
+  <modelVersion>4.0.0</modelVersion>
+  <artifactId>core-java-booleans</artifactId>
+  <version>0.1.0-SNAPSHOT</version>
+  <name>core-java-booleans</name>
+  <packaging>jar</packaging>
+
+  <parent>
+    <groupId>com.baeldung.core-java-modules</groupId>
+    <artifactId>core-java-modules</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+  </parent>
+</project>

core-java-modules/core-java-booleans/src/test/java/com/baeldung/booleans/BooleanToStringUnitTest.java

@@ -0,0 +1,48 @@
+package com.baeldung.booleans;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class BooleanToStringUnitTest {
+    String optionToString(String optionName, boolean optionValue) {
+        return String.format("The option '%s' is %s.", optionName, optionValue ? "Enabled" : "Disabled");
+    }
+
+    @Test
+    void givenPrimitiveBoolean_whenConvertingUsingTernaryOperator_thenSuccess() {
+        boolean primitiveBoolean = true;
+        assertEquals("true", primitiveBoolean ? "true" : "false");
+
+        primitiveBoolean = false;
+        assertEquals("false", primitiveBoolean ? "true" : "false");
+
+        assertEquals("The option 'IgnoreWarnings' is Enabled.", optionToString("IgnoreWarnings", true));
+    }
+
+
+    @Test
+    void givenBooleanObject_whenConvertingUsingBooleanToString_thenSuccess() {
+        Boolean myBoolean = Boolean.TRUE;
+        assertEquals("true", myBoolean.toString());
+
+        myBoolean = Boolean.FALSE;
+        assertEquals("false", myBoolean.toString());
+
+        Boolean nullBoolean = null;
+        assertThrows(NullPointerException.class, () -> nullBoolean.toString());
+    }
+
+    @Test
+    void givenBooleanObject_whenConvertingUsingStringValueOf_thenSuccess() {
+        Boolean myBoolean = Boolean.TRUE;
+        assertEquals("true", String.valueOf(myBoolean));
+
+        myBoolean = Boolean.FALSE;
+        assertEquals("false", String.valueOf(myBoolean));
+
+        Boolean nullBoolean = null;
+        assertEquals("null", String.valueOf(nullBoolean));
+    }
+}

core-java-modules/pom.xml

@@ -38,6 +38,7 @@
         <module>core-java-arrays-convert</module>
         <module>core-java-arrays-operations-basic</module>
         <module>core-java-arrays-operations-advanced</module>
+        <module>core-java-booleans</module>
         <module>core-java-char</module>
         <module>core-java-collections</module>
         <module>core-java-collections-2</module>