Merge branch 'master' of https://github.com/eugenp/tutorials

2019-07-28 16:05:52 +05:30
parent 6a29eab820 ba31134cfd
commit 3b3a0fcd67
182 changed files with 3714 additions and 568 deletions
@@ -1,12 +1,16 @@

-The "REST with Spring" Classes
+The Courses
 ==============================

-Here's the Master Class of REST With Spring (along with the newly announced Boot 2 material): <br/>
-**[>> THE REST WITH SPRING - MASTER CLASS](http://www.baeldung.com/rest-with-spring-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=rws#master-class)**

-And here's the Master Class of Learn Spring Security: <br/>
-**[>> LEARN SPRING SECURITY - MASTER CLASS](http://www.baeldung.com/learn-spring-security-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=lss#master-class)**
+Here's the new "Learn Spring" course: <br/>
+**[>> LEARN SPRING - THE MASTER CLASS](https://www.baeldung.com/learn-spring-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=ls#master-class)**
+
+Here's the Master Class of "REST With Spring" (along with the new announced Boot 2 material): <br/>
+**[>> THE REST WITH SPRING - MASTER CLASS](https://www.baeldung.com/rest-with-spring-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=rws#master-class)**
+
+And here's the Master Class of "Learn Spring Security": <br/>
+**[>> LEARN SPRING SECURITY - MASTER CLASS](https://www.baeldung.com/learn-spring-security-course?utm_source=github&utm_medium=social&utm_content=tutorials&utm_campaign=lss#master-class)**



@@ -15,7 +19,7 @@ Java and Spring Tutorials

 This project is **a collection of small and focused tutorials** - each covering a single and well defined area of development in the Java ecosystem. 
 A strong focus of these is, of course, the Spring Framework - Spring, Spring Boot and Spring Security. 
-In additional to Spring, the following technologies are in focus: `core Java`, `Jackson`, `HttpClient`, `Guava`. 
+In additional to Spring, the modules here are covering a number of aspects in Java. 


 Building the project
@@ -32,8 +36,15 @@ Running a Spring Boot module
 ====================
 To run a Spring Boot module run the command: `mvn spring-boot:run` in the module directory

-###Running Tests

+Working with the IDE
+====================
+This repo contains a large number of modules. 
+When you're working with an individual module, there's no need to import all of them (or build all of them) - you can simply import that particular module in either Eclipse or IntelliJ. 
+
+
+Running Tests
+=============
 The command `mvn clean install` will run the unit tests in a module.
 To run the integration tests, use the command `mvn clean install -Pintegration-lite-first`

@@ -0,0 +1,30 @@
+package com.baeldung.algorithms.stringsortingbynumber;
+
+import java.util.Comparator;
+
+public final class NaturalOrderComparators {
+
+    private static final String DIGIT_AND_DECIMAL_REGEX = "[^\\d.]";
+
+    private NaturalOrderComparators() {
+        throw new AssertionError("Let's keep this static");
+    }
+
+    public static Comparator<String> createNaturalOrderRegexComparator() {
+        return Comparator.comparingDouble(NaturalOrderComparators::parseStringToNumber);
+    }
+
+    private static double parseStringToNumber(String input){
+
+        final String digitsOnly = input.replaceAll(DIGIT_AND_DECIMAL_REGEX, "");
+
+        if("".equals(digitsOnly)) return 0;
+
+        try{
+            return Double.parseDouble(digitsOnly);
+        }catch (NumberFormatException nfe){
+            return 0;
+        }
+    }
+
+}
@@ -0,0 +1,79 @@
+package com.baeldung.algorithms.stringsortingbynumber;
+
+import com.baeldung.algorithms.stringsortingbynumber.NaturalOrderComparators;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.*;
+
+public class NaturalOrderComparatorsUnitTest {
+
+    @Test
+    public void givenSimpleStringsContainingIntsAndDoubles_whenSortedByRegex_checkSortingCorrect() {
+
+        List<String> testStrings = Arrays.asList("a1", "b3", "c4", "d2.2", "d2.4", "d2.3d");
+
+        testStrings.sort(NaturalOrderComparators.createNaturalOrderRegexComparator());
+
+        List<String> expected = Arrays.asList("a1", "d2.2", "d2.3d", "d2.4", "b3", "c4");
+
+        assertEquals(expected, testStrings);
+
+
+    }
+
+    @Test
+    public void givenSimpleStringsContainingIntsAndDoublesWithAnInvalidNumber_whenSortedByRegex_checkSortingCorrect() {
+
+        List<String> testStrings = Arrays.asList("a1", "b3", "c4", "d2.2", "d2.4", "d2.3.3d");
+
+        testStrings.sort(NaturalOrderComparators.createNaturalOrderRegexComparator());
+
+        List<String> expected = Arrays.asList("d2.3.3d", "a1", "d2.2", "d2.4", "b3", "c4");
+
+        assertEquals(expected, testStrings);
+
+
+    }
+
+    @Test
+    public void givenAllForseenProblems_whenSortedByRegex_checkSortingCorrect() {
+
+        List<String> testStrings = Arrays.asList("a1", "b3", "c4", "d2.2", "d2.f4", "d2.3.3d");
+
+        testStrings.sort(NaturalOrderComparators.createNaturalOrderRegexComparator());
+
+        List<String> expected = Arrays.asList("d2.3.3d", "a1", "d2.2", "d2.f4", "b3", "c4");
+
+        assertEquals(expected, testStrings);
+
+
+    }
+
+    @Test
+    public void givenComplexStringsContainingSeparatedNumbers_whenSortedByRegex_checkNumbersCondensedAndSorted() {
+
+        List<String> testStrings = Arrays.asList("a1b2c5", "b3ght3.2", "something65.thensomething5"); //125, 33.2, 65.5
+
+        List<String> expected = Arrays.asList("b3ght3.2", "something65.thensomething5", "a1b2c5" );
+
+        testStrings.sort(NaturalOrderComparators.createNaturalOrderRegexComparator());
+
+        assertEquals(expected, testStrings);
+
+    }
+
+    @Test
+    public void givenStringsNotContainingNumbers_whenSortedByRegex_checkOrderNotChanged() {
+
+        List<String> testStrings = Arrays.asList("a", "c", "d", "e");
+        List<String> expected = new ArrayList<>(testStrings);
+
+        testStrings.sort(NaturalOrderComparators.createNaturalOrderRegexComparator());
+
+        assertEquals(expected, testStrings);
+    }
+}
@@ -1,3 +1,4 @@
-## Relevant articles:
+## Relevant Articles:
+

 - [String API Updates in Java 12](https://www.baeldung.com/java12-string-api)
@@ -0,0 +1,25 @@
+*.class
+
+0.*
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+.resourceCache
+
+# Packaged files #
+*.jar
+*.war
+*.ear
+
+# Files generated by integration tests
+backup-pom.xml
+/bin/
+/temp
+
+#IntelliJ specific
+.idea/
+*.iml
@@ -0,0 +1,50 @@
+<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>
+    <groupId>com.baeldung</groupId>
+    <artifactId>core-java-arrays-2</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-arrays-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-arrays-2</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+
+        <!-- util -->
+        <commons-lang3.version>3.9</commons-lang3.version>
+        <!-- testing -->
+        <assertj-core.version>3.10.0</assertj-core.version>
+    </properties>
+
+</project>
@@ -4,7 +4,7 @@ import org.junit.Test;

 import static org.junit.Assert.assertEquals;

-public class LoopDiagonallyTest {
+public class LoopDiagonallyUnitTest {

    @Test
    public void twoArrayIsLoopedDiagonallyAsExpected() {
@@ -2,7 +2,10 @@ package com.baeldung.array;

 import com.baeldung.arraycopy.model.Employee;

+import java.util.Comparator;
+
 public class SortedArrayChecker {
+
    boolean isSorted(int[] array, int length) {
        if (array == null || length < 2)
            return true;
@@ -22,7 +25,7 @@ public class SortedArrayChecker {
        return true;
    }

-    boolean isSorted(String[] array, int length) {
+    boolean isSorted(Comparable[] array, int length) {
        if (array == null || length < 2)
            return true;

@@ -32,40 +35,31 @@ public class SortedArrayChecker {
        return isSorted(array, length - 1);
    }

-boolean isSorted(String[] array) {
-    for (int i = 0; i < array.length - 1; ++i) {
-        if (array[i].compareTo(array[i + 1]) > 0)
-            return false;
-    }
-
-    return true;
-}
-
-    boolean isSortedByName(Employee[] array) {
+    boolean isSorted(Comparable[] array) {
        for (int i = 0; i < array.length - 1; ++i) {
-            if (array[i].getName().compareTo(array[i + 1].getName()) > 0)
+            if (array[i].compareTo(array[i + 1]) > 0)
                return false;
        }

        return true;
    }

-boolean isSortedByAge(Employee[] array) {
-    for (int i = 0; i < array.length - 1; ++i) {
-        if (array[i].getAge() > (array[i + 1].getAge()))
-            return false;
+    boolean isSorted(Object[] array, Comparator comparator) {
+        for (int i = 0; i < array.length - 1; ++i) {
+            if (comparator.compare(array[i], (array[i + 1])) > 0)
+                return false;
+        }
+
+        return true;
    }

-    return true;
-}
-
-    boolean isSortedByAge(Employee[] array, int length) {
+    boolean isSorted(Object[] array, Comparator comparator, int length) {
        if (array == null || length < 2)
            return true;

-        if (array[length - 2].getAge() > array[length - 1].getAge())
+        if (comparator.compare(array[length - 2], array[length - 1]) > 0)
            return false;

-        return isSortedByAge(array, length - 1);
+        return isSorted(array, comparator, length - 1);
    }
 }
@@ -4,32 +4,33 @@ import com.baeldung.arraycopy.model.Employee;
 import org.junit.Before;
 import org.junit.Test;

+import java.util.Comparator;
+
 import static org.assertj.core.api.Assertions.assertThat;

-class SortedArrayCheckerUnitTest {
-
+public class SortedArrayCheckerUnitTest {
    private static final int[] INTEGER_SORTED = {1, 3, 5, 7, 9};
    private static final int[] INTEGER_NOT_SORTED = {1, 3, 11, 7};

    private static final String[] STRING_SORTED = {"abc", "cde", "fgh"};
    private static final String[] STRING_NOT_SORTED = {"abc", "fgh", "cde", "ijk"};

-    private final Employee[] EMPLOYEES_SORTED_BY_NAME = {
+    private static final Employee[] EMPLOYEES_SORTED_BY_NAME = {
            new Employee(1, "Carlos", 26),
            new Employee(2, "Daniel", 31),
            new Employee(3, "Marta", 27)};

-    private final Employee[] EMPLOYEES_NOT_SORTED_BY_NAME = {
+    private static final Employee[] EMPLOYEES_NOT_SORTED_BY_NAME = {
            new Employee(1, "Daniel", 31),
            new Employee(2, "Carlos", 26),
            new Employee(3, "Marta", 27)};

-    private final Employee[] EMPLOYEES_SORTED_BY_AGE = {
+    private static final Employee[] EMPLOYEES_SORTED_BY_AGE = {
            new Employee(1, "Carlos", 26),
            new Employee(2, "Marta", 27),
            new Employee(3, "Daniel", 31)};

-    private final Employee[] EMPLOYEES_NOT_SORTED_BY_AGE = {
+    private static final Employee[] EMPLOYEES_NOT_SORTED_BY_AGE = {
            new Employee(1, "Marta", 27),
            new Employee(2, "Carlos", 26),
            new Employee(3, "Daniel", 31)};
@@ -61,13 +62,18 @@ class SortedArrayCheckerUnitTest {

    @Test
    public void givenEmployeeArray_thenReturnIfItIsSortedOrNot() {
-        assertThat(sortedArrayChecker.isSortedByName(EMPLOYEES_SORTED_BY_NAME)).isEqualTo(true);
-        assertThat(sortedArrayChecker.isSortedByName(EMPLOYEES_NOT_SORTED_BY_NAME)).isEqualTo(false);
+        assertThat(sortedArrayChecker.isSorted(EMPLOYEES_SORTED_BY_NAME, Comparator.comparing(Employee::getName))).isEqualTo(true);
+        assertThat(sortedArrayChecker.isSorted(EMPLOYEES_NOT_SORTED_BY_NAME, Comparator.comparing(Employee::getName))).isEqualTo(false);

-        assertThat(sortedArrayChecker.isSortedByAge(EMPLOYEES_SORTED_BY_AGE)).isEqualTo(true);
-        assertThat(sortedArrayChecker.isSortedByAge(EMPLOYEES_NOT_SORTED_BY_AGE)).isEqualTo(false);
+        assertThat(sortedArrayChecker.isSorted(EMPLOYEES_SORTED_BY_AGE, Comparator.comparingInt(Employee::getAge))).isEqualTo(true);
+        assertThat(sortedArrayChecker.isSorted(EMPLOYEES_NOT_SORTED_BY_AGE, Comparator.comparingInt(Employee::getAge))).isEqualTo(false);

-        assertThat(sortedArrayChecker.isSortedByAge(EMPLOYEES_SORTED_BY_AGE, EMPLOYEES_SORTED_BY_AGE.length)).isEqualTo(true);
-        assertThat(sortedArrayChecker.isSortedByAge(EMPLOYEES_NOT_SORTED_BY_AGE, EMPLOYEES_NOT_SORTED_BY_AGE.length)).isEqualTo(false);
+        assertThat(sortedArrayChecker
+                .isSorted(EMPLOYEES_SORTED_BY_AGE, Comparator.comparingInt(Employee::getAge), EMPLOYEES_SORTED_BY_AGE.length))
+                .isEqualTo(true);
+        assertThat(sortedArrayChecker
+                .isSorted(EMPLOYEES_NOT_SORTED_BY_AGE, Comparator.comparingInt(Employee::getAge), EMPLOYEES_NOT_SORTED_BY_AGE.length))
+                .isEqualTo(false);
    }
+
 }
@@ -1,3 +1,3 @@
-## Relevant articles:
+## Relevant Articles:

 - [Will an Error Be Caught by Catch Block in Java?](https://www.baeldung.com/java-error-catch)
@@ -0,0 +1,25 @@
+*.class
+
+0.*
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+.resourceCache
+
+# Packaged files #
+*.jar
+*.war
+*.ear
+
+# Files generated by integration tests
+backup-pom.xml
+/bin/
+/temp
+
+#IntelliJ specific
+.idea/
+*.iml
@@ -0,0 +1,20 @@
+<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-networking-2</artifactId>
+    <name>core-java-networking-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-networking-2</finalName>
+    </build>	
+</project>
@@ -0,0 +1,25 @@
+package com.baeldung.url;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+public class UrlChecker {
+
+    public int getResponseCodeForURL(String address) throws IOException {
+        return getResponseCodeForURLUsing(address, "GET");
+    }
+
+    public int getResponseCodeForURLUsingHead(String address) throws IOException {
+        return getResponseCodeForURLUsing(address, "HEAD");
+    }
+
+    private int getResponseCodeForURLUsing(String address, String method) throws IOException {
+        HttpURLConnection.setFollowRedirects(false); // Set follow redirects to false
+        final URL url = new URL(address);
+        HttpURLConnection huc = (HttpURLConnection) url.openConnection();
+        huc.setRequestMethod(method);
+        return huc.getResponseCode();
+    }
+
+}
@@ -0,0 +1,39 @@
+package com.baeldung.url;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.IOException;
+
+import org.junit.Test;
+
+public class UrlCheckerUnitTest {
+
+    @Test
+    public void givenValidUrl_WhenUsingHEAD_ThenReturn200() throws IOException {
+        UrlChecker tester = new UrlChecker();
+        int responseCode = tester.getResponseCodeForURLUsingHead("http://www.example.com");
+        assertEquals(200, responseCode);
+    }
+    
+    @Test
+    public void givenInvalidIUrl_WhenUsingHEAD_ThenReturn404() throws IOException {
+        UrlChecker tester = new UrlChecker();
+        int responseCode = tester.getResponseCodeForURLUsingHead("http://www.example.com/unkownurl");
+        assertEquals(404, responseCode);
+    }
+    
+    @Test
+    public void givenValidUrl_WhenUsingGET_ThenReturn200() throws IOException {
+        UrlChecker tester = new UrlChecker();
+        int responseCode = tester.getResponseCodeForURL("http://www.example.com");
+        assertEquals(200, responseCode);
+    }
+    
+    @Test
+    public void givenInvalidIUrl_WhenUsingGET_ThenReturn404() throws IOException {
+        UrlChecker tester = new UrlChecker();
+        int responseCode = tester.getResponseCodeForURL("http://www.example.com/unkownurl");
+        assertEquals(404, responseCode);
+    }
+    
+}
@@ -0,0 +1,3 @@
+## Relevant Articles
+
+- [Multi-Module Maven Application with Java Modules](https://www.baeldung.com/maven-multi-module-project-java-jpms)
@@ -17,6 +17,7 @@
        <module>pre-jpms</module>
        <module>core-java-exceptions</module>
        <module>core-java-optional</module>
+        <module>core-java-networking-2</module>
    </modules>
    
 </project>
@@ -0,0 +1,72 @@
+package com.baeldung.graph;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Stack;
+
+public class Graph {
+
+    private Map<Integer, List<Integer>> adjVertices;
+
+    public Graph() {
+        this.adjVertices = new HashMap<Integer, List<Integer>>();
+    }
+
+    public void addVertex(int vertex) {
+        adjVertices.putIfAbsent(vertex, new ArrayList<>());
+    }
+
+    public void addEdge(int src, int dest) {
+        adjVertices.get(src).add(dest);
+    }
+
+    public void dfsWithoutRecursion(int start) {
+        Stack<Integer> stack = new Stack<Integer>();
+        boolean[] isVisited = new boolean[adjVertices.size()];
+        stack.push(start);
+        while (!stack.isEmpty()) {
+            int current = stack.pop();
+            isVisited[current] = true;
+            System.out.print(" " + current);
+            for (int dest : adjVertices.get(current)) {
+                if (!isVisited[dest])
+                    stack.push(dest);
+            }
+        }
+    }
+
+    public void dfs(int start) {
+        boolean[] isVisited = new boolean[adjVertices.size()];
+        dfsRecursive(start, isVisited);
+    }
+
+    private void dfsRecursive(int current, boolean[] isVisited) {
+        isVisited[current] = true;
+        System.out.print(" " + current);
+        for (int dest : adjVertices.get(current)) {
+            if (!isVisited[dest])
+                dfsRecursive(dest, isVisited);
+        }
+    }
+
+    public void topologicalSort(int start) {
+        Stack<Integer> result = new Stack<Integer>();
+        boolean[] isVisited = new boolean[adjVertices.size()];
+        topologicalSortRecursive(start, isVisited, result);
+        while (!result.isEmpty()) {
+            System.out.print(" " + result.pop());
+        }
+    }
+
+    private void topologicalSortRecursive(int current, boolean[] isVisited, Stack<Integer> result) {
+        isVisited[current] = true;
+        for (int dest : adjVertices.get(current)) {
+            if (!isVisited[dest])
+                topologicalSortRecursive(dest, isVisited, result);
+        }
+        result.push(current);
+    }
+
+}
@@ -2,6 +2,7 @@ package com.baeldung.tree;

 import java.util.LinkedList;
 import java.util.Queue;
+import java.util.Stack;

 public class BinaryTree {

@@ -147,6 +148,68 @@ public class BinaryTree {
        }
    }

+    
+    public void traverseInOrderWithoutRecursion() {
+        Stack<Node> stack = new Stack<Node>();
+        Node current = root;
+        stack.push(root);
+        while(! stack.isEmpty()) {
+            while(current.left != null) {
+                current = current.left;                
+                stack.push(current);                
+            }
+            current = stack.pop();
+            System.out.print(" " + current.value);
+            if(current.right != null) {
+                current = current.right;                
+                stack.push(current);
+            }
+        }
+    }
+    
+    public void traversePreOrderWithoutRecursion() {
+        Stack<Node> stack = new Stack<Node>();
+        Node current = root;
+        stack.push(root);
+        while(! stack.isEmpty()) {
+            current = stack.pop();
+            System.out.print(" " + current.value);
+            
+            if(current.right != null)
+                stack.push(current.right);
+                
+            if(current.left != null)
+                stack.push(current.left);
+        }        
+    }
+    
+    public void traversePostOrderWithoutRecursion() {
+        Stack<Node> stack = new Stack<Node>();
+        Node prev = root;
+        Node current = root;
+        stack.push(root);
+
+        while (!stack.isEmpty()) {
+            current = stack.peek();
+            boolean hasChild = (current.left != null || current.right != null);
+            boolean isPrevLastChild = (prev == current.right || (prev == current.left && current.right == null));
+
+            if (!hasChild || isPrevLastChild) {
+                current = stack.pop();
+                System.out.print(" " + current.value);
+                prev = current;
+            } else {
+                if (current.right != null) {
+                    stack.push(current.right);
+                }
+                if (current.left != null) {
+                    stack.push(current.left);
+                }
+            }
+        }   
+    }    
+    
+    
    class Node {
        int value;
        Node left;
@@ -0,0 +1,37 @@
+package com.baeldung.graph;
+
+import org.junit.Test;
+
+public class GraphUnitTest {
+
+    @Test
+    public void givenDirectedGraph_whenDFS_thenPrintAllValues() {
+        Graph graph = createDirectedGraph();
+        graph.dfs(0);
+        System.out.println();
+        graph.dfsWithoutRecursion(0);
+    }
+
+    @Test
+    public void givenDirectedGraph_whenGetTopologicalSort_thenPrintValuesSorted() {
+        Graph graph = createDirectedGraph();
+        graph.topologicalSort(0);
+    }
+
+    private Graph createDirectedGraph() {
+        Graph graph = new Graph();
+        graph.addVertex(0);
+        graph.addVertex(1);
+        graph.addVertex(2);
+        graph.addVertex(3);
+        graph.addVertex(4);
+        graph.addVertex(5);
+        graph.addEdge(0, 1);
+        graph.addEdge(0, 2);
+        graph.addEdge(1, 3);
+        graph.addEdge(2, 3);
+        graph.addEdge(3, 4);
+        graph.addEdge(4, 5);
+        return graph;
+    }
+}
@@ -87,6 +87,8 @@ public class BinaryTreeUnitTest {
        BinaryTree bt = createBinaryTree();

        bt.traverseInOrder(bt.root);
+        System.out.println();
+        bt.traverseInOrderWithoutRecursion();
    }

    @Test
@@ -95,6 +97,8 @@ public class BinaryTreeUnitTest {
        BinaryTree bt = createBinaryTree();

        bt.traversePreOrder(bt.root);
+        System.out.println();
+        bt.traversePreOrderWithoutRecursion();
    }

    @Test
@@ -103,6 +107,8 @@ public class BinaryTreeUnitTest {
        BinaryTree bt = createBinaryTree();

        bt.traversePostOrder(bt.root);
+        System.out.println();
+        bt.traversePostOrderWithoutRecursion();
    }

    @Test
@@ -0,0 +1,29 @@
+package com.baeldung.string.changecase;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Locale;
+
+import org.junit.Test;
+
+public class ToLowerCaseUnitTest {
+
+    private static final Locale TURKISH = new Locale("tr");
+    private String name = "John Doe";
+    private String foreignUppercase = "\u0049";
+
+    @Test
+    public void givenMixedCaseString_WhenToLowerCase_ThenResultIsLowerCase() {
+        assertEquals("john doe", name.toLowerCase());
+    }
+
+    @Test
+    public void givenForeignString_WhenToLowerCaseWithoutLocale_ThenResultIsLowerCase() {
+        assertEquals("\u0069", foreignUppercase.toLowerCase());
+    }
+
+    @Test
+    public void givenForeignString_WhenToLowerCaseWithLocale_ThenResultIsLowerCase() {
+        assertEquals("\u0131", foreignUppercase.toLowerCase(TURKISH));
+    }
+}
@@ -0,0 +1,29 @@
+package com.baeldung.string.changecase;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Locale;
+
+import org.junit.Test;
+
+public class ToUpperCaseUnitTest {
+
+    private static final Locale TURKISH = new Locale("tr");
+    private String name = "John Doe";
+    private String foreignLowercase = "\u0069";
+
+    @Test
+    public void givenMixedCaseString_WhenToUpperCase_ThenResultIsUpperCase() {
+        assertEquals("JOHN DOE", name.toUpperCase());
+    }
+
+    @Test
+    public void givenForeignString_WhenToUpperCaseWithoutLocale_ThenResultIsUpperCase() {
+        assertEquals("\u0049", foreignLowercase.toUpperCase());
+    }
+
+    @Test
+    public void givenForeignString_WhenToUpperCaseWithLocale_ThenResultIsUpperCase() {
+        assertEquals("\u0130", foreignLowercase.toUpperCase(TURKISH));
+    }
+}
@@ -0,0 +1,19 @@
+package org.baeldung.javabeanconstraints.bigdecimal;
+
+import java.math.BigDecimal;
+
+import javax.validation.constraints.DecimalMin;
+import javax.validation.constraints.Digits;
+
+public class Invoice {
+	
+	@DecimalMin(value = "0.0", inclusive = false)
+	@Digits(integer=3, fraction=2)
+    private BigDecimal price;
+    private String description;
+    
+	public Invoice(BigDecimal price, String description) {
+		this.price = price;
+		this.description = description;
+	}
+}
@@ -0,0 +1,62 @@
+package org.baeldung.javabeanconstraints.bigdecimal;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.math.BigDecimal;
+import java.util.Set;
+
+import javax.validation.ConstraintViolation;
+import javax.validation.Validation;
+import javax.validation.Validator;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class InvoiceUnitTest {
+	
+	private static Validator validator;
+
+    @BeforeClass
+    public static void setupValidatorInstance() {
+        validator = Validation.buildDefaultValidatorFactory().getValidator();
+    }
+    
+    @Test
+    public void whenPriceIntegerDigitLessThanThreeWithDecimalValue_thenShouldGiveConstraintViolations() {
+    	Invoice invoice = new Invoice(new BigDecimal(10.21), "Book purchased");
+        Set<ConstraintViolation<Invoice>> violations = validator.validate(invoice);
+        assertThat(violations.size()).isEqualTo(1);
+        violations.forEach(action-> assertThat(action.getMessage()).isEqualTo("numeric value out of bounds (<3 digits>.<2 digits> expected)"));
+    }
+    
+    @Test
+    public void whenPriceIntegerDigitLessThanThreeWithIntegerValue_thenShouldNotGiveConstraintViolations() {
+    	Invoice invoice = new Invoice(new BigDecimal(10), "Book purchased");
+        Set<ConstraintViolation<Invoice>> violations = validator.validate(invoice);
+        assertThat(violations.size()).isEqualTo(0);
+    }
+    
+    @Test
+    public void whenPriceIntegerDigitGreaterThanThree_thenShouldGiveConstraintViolations() {
+    	Invoice invoice = new Invoice(new BigDecimal(1021.21), "Book purchased");
+        Set<ConstraintViolation<Invoice>> violations = validator.validate(invoice);
+        assertThat(violations.size()).isEqualTo(1);
+        violations.forEach(action-> assertThat(action.getMessage()).isEqualTo("numeric value out of bounds (<3 digits>.<2 digits> expected)"));
+    }
+    
+    @Test
+    public void whenPriceIsZero_thenShouldGiveConstraintViolations() {
+    	Invoice invoice = new Invoice(new BigDecimal(000.00), "Book purchased");
+        Set<ConstraintViolation<Invoice>> violations = validator.validate(invoice);
+        assertThat(violations.size()).isEqualTo(1);
+        violations.forEach(action-> assertThat(action.getMessage()).isEqualTo("must be greater than 0.0"));
+    }
+    
+    @Test
+    public void whenPriceIsGreaterThanZero_thenShouldNotGiveConstraintViolations() {
+    	Invoice invoice = new Invoice(new BigDecimal(100.50), "Book purchased");
+        Set<ConstraintViolation<Invoice>> violations = validator.validate(invoice);
+        assertThat(violations.size()).isEqualTo(0);
+    }
+
+}
--- a/Show More
+++ b/Show More