Merge pull request #13 from eugenp/master

update master

README.md

@@ -1,3 +1,4 @@
+**UPDATE**: The price of "Learn Spring Security OAuth" will permanently change on the 11th of December, along with the upcoming OAuth2 material: http://bit.ly/github-lss
 
 The Courses
 ==============================

algorithms-miscellaneous-5/src/main/java/com/baeldung/algorithms/mergesortedarrays/SortedArrays.java

@@ -0,0 +1,33 @@
+package com.baeldung.algorithms.mergesortedarrays;
+
+public class SortedArrays {
+
+    public static int[] merge(int[] foo, int[] bar) {
+
+        int fooLength = foo.length;
+        int barLength = bar.length;
+
+        int[] merged = new int[fooLength + barLength];
+
+        int fooPosition, barPosition, mergedPosition;
+        fooPosition = barPosition = mergedPosition = 0;
+
+        while (fooPosition < fooLength && barPosition < barLength) {
+            if (foo[fooPosition] < bar[barPosition]) {
+                merged[mergedPosition++] = foo[fooPosition++];
+            } else {
+                merged[mergedPosition++] = bar[barPosition++];
+            }
+        }
+
+        while (fooPosition < fooLength) {
+            merged[mergedPosition++] = foo[fooPosition++];
+        }
+
+        while (barPosition < barLength) {
+            merged[mergedPosition++] = bar[barPosition++];
+        }
+
+        return merged;
+    }
+}

algorithms-miscellaneous-5/src/test/java/com/baeldung/algorithms/mergesortedarrays/SortedArraysUnitTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.algorithms.mergesortedarrays;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.algorithms.mergesortedarrays.SortedArrays;
+
+public class SortedArraysUnitTest {
+
+    @Test
+    public void givenTwoSortedArrays_whenMerged_thenReturnMergedSortedArray() {
+
+        int[] foo = { 3, 7 };
+        int[] bar = { 4, 8, 11 };
+        int[] merged = { 3, 4, 7, 8, 11 };
+
+        assertArrayEquals(merged, SortedArrays.merge(foo, bar));
+    }
+
+    @Test
+    public void givenTwoSortedArraysWithDuplicates_whenMerged_thenReturnMergedSortedArray() {
+
+        int[] foo = { 3, 3, 7 };
+        int[] bar = { 4, 8, 8, 11 };
+        int[] merged = { 3, 3, 4, 7, 8, 8, 11 };
+
+        assertArrayEquals(merged, SortedArrays.merge(foo, bar));
+    }
+}

aws/README.md

@@ -1,6 +1,6 @@
 ## AWS
 
-This module contains articles about AWS
+This module contains articles about Amazon Web Services (AWS)
 
 ### Relevant articles
 

core-java-modules/core-java-concurrency-advanced-2/README.md

@@ -1,5 +1,3 @@
-=========
-
 ## Core Java Concurrency Advanced Examples
 
 This module contains articles about advanced topics about multithreading with core Java.

core-java-modules/core-java-concurrency-basic-2/README.md

@@ -1,6 +1,6 @@
-=========
+## Core Java Concurrency Basic
 
-## Core Java Concurrency Basic 2 Examples
+This module contains articles about basic Java concurrency
 
 ### Relevant Articles: 
 - [How to Delay Code Execution in Java](https://www.baeldung.com/java-delay-code-execution)
@@ -8,3 +8,4 @@
 - [Difference Between Wait and Sleep in Java](https://www.baeldung.com/java-wait-and-sleep)
 - [Guide to the Synchronized Keyword in Java](https://www.baeldung.com/java-synchronized)
 - [Life Cycle of a Thread in Java](https://www.baeldung.com/java-thread-lifecycle)
+- [[<-- Prev]](/core-java-modules/core-java-concurrency-basic)

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

@@ -17,3 +17,4 @@ This module contains articles about core java exceptions
 - [Common Java Exceptions](https://www.baeldung.com/java-common-exceptions)
 - [How to Find an Exception’s Root Cause in Java](https://www.baeldung.com/java-exception-root-cause)
 - [Is It a Bad Practice to Catch Throwable?](https://www.baeldung.com/java-catch-throwable-bad-practice)
+- [[Next -->]](/core-java-modules/core-java-exceptions-2)

core-java-modules/core-java-io-apis/src/test/java/com/baeldung/file/FileClassUnitTest.java

@@ -156,10 +156,16 @@ public class FileClassUnitTest {
 
     private static File makeDir(String name) {
         File directory = new File(name);
-        directory.mkdir();
-        if (directory.isDirectory()) {
+
+        // If the directory already exists, make sure we create it 'from scratch', i.e. all the files inside are deleted first
+        if (directory.exists()) {
+            removeDir(directory);
+        }
+
+        if (directory.mkdir()) {
             return directory;
         }
+
         throw new RuntimeException("'" + name + "' not made!");
     }
 

core-java-modules/core-java-lang-math/src/test/java/com/baeldung/overflow/OverflowUnitTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.overflow;
+
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class OverflowUnitTest {
+
+    @Test
+    public void positive_and_negative_zero_are_not_always_equal() {
+
+        double a = +0f;
+        double b = -0f;
+
+        assertTrue(a == b);
+
+        assertTrue(1/a == Double.POSITIVE_INFINITY);
+        assertTrue(1/b == Double.NEGATIVE_INFINITY);
+
+        assertTrue(1/a != 1/b);
+    }
+}

data-structures/src/main/java/com/baeldung/printbinarytree/BinaryTreeModel.java

@@ -0,0 +1,37 @@
+package com.baeldung.printbinarytree;
+
+public class BinaryTreeModel {
+
+    private Object value;
+    private BinaryTreeModel left;
+    private BinaryTreeModel right;
+
+    public BinaryTreeModel(Object value) {
+        this.value = value;
+    }
+
+    public Object getValue() {
+        return value;
+    }
+
+    public void setValue(Object value) {
+        this.value = value;
+    }
+
+    public BinaryTreeModel getLeft() {
+        return left;
+    }
+
+    public void setLeft(BinaryTreeModel left) {
+        this.left = left;
+    }
+
+    public BinaryTreeModel getRight() {
+        return right;
+    }
+
+    public void setRight(BinaryTreeModel right) {
+        this.right = right;
+    }
+
+}

data-structures/src/main/java/com/baeldung/printbinarytree/BinaryTreePrinter.java

@@ -0,0 +1,63 @@
+package com.baeldung.printbinarytree;
+
+import java.io.PrintStream;
+
+public class BinaryTreePrinter {
+
+    private BinaryTreeModel tree;
+
+    public BinaryTreePrinter(BinaryTreeModel tree) {
+        this.tree = tree;
+    }
+
+    private String traversePreOrder(BinaryTreeModel root) {
+
+        if (root == null) {
+            return "";
+        }
+
+        StringBuilder sb = new StringBuilder();
+        sb.append(root.getValue());
+
+        String pointerRight = "└──";
+        String pointerLeft = (root.getRight() != null) ? "├──" : "└──";
+
+        traverseNodes(sb, "", pointerLeft, root.getLeft(), root.getRight() != null);
+        traverseNodes(sb, "", pointerRight, root.getRight(), false);
+
+        return sb.toString();
+    }
+
+    private void traverseNodes(StringBuilder sb, String padding, String pointer, BinaryTreeModel node,
+        boolean hasRightSibling) {
+
+        if (node != null) {
+
+            sb.append("\n");
+            sb.append(padding);
+            sb.append(pointer);
+            sb.append(node.getValue());
+
+            StringBuilder paddingBuilder = new StringBuilder(padding);
+            if (hasRightSibling) {
+                paddingBuilder.append("│  ");
+            } else {
+                paddingBuilder.append("   ");
+            }
+
+            String paddingForBoth = paddingBuilder.toString();
+            String pointerRight = "└──";
+            String pointerLeft = (node.getRight() != null) ? "├──" : "└──";
+
+            traverseNodes(sb, paddingForBoth, pointerLeft, node.getLeft(), node.getRight() != null);
+            traverseNodes(sb, paddingForBoth, pointerRight, node.getRight(), false);
+
+        }
+
+    }
+
+    public void print(PrintStream os) {
+        os.print(traversePreOrder(tree));
+    }
+
+}

data-structures/src/test/java/com/baeldung/printbinarytree/PrintingBinaryTreeModelUnitTest.java

@@ -0,0 +1,178 @@
+package com.baeldung.printbinarytree;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.io.ByteArrayOutputStream;
+import java.io.OutputStream;
+import java.io.PrintStream;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.baeldung.printbinarytree.BinaryTreeModel;
+import com.baeldung.printbinarytree.BinaryTreePrinter;
+
+public class PrintingBinaryTreeModelUnitTest {
+
+    private BinaryTreeModel balanced;
+    private BinaryTreeModel leftSkewed;
+    private BinaryTreeModel rightSkewed;
+    
+    private OutputStream output;
+
+    @Before
+    public void setup() {
+        balanced = createBalancedTree();
+        leftSkewed = createLeftUnbalancedTree();
+        rightSkewed = createRightUnbalancedTree();
+        
+        output = new ByteArrayOutputStream();
+        System.setOut(new PrintStream(output));
+    }
+    
+    @After
+    public void tearDown() {
+        System.setOut(System.out);
+    }
+    
+    private BinaryTreeModel createBalancedTree() {
+        
+        BinaryTreeModel root = new BinaryTreeModel("root");
+        
+        BinaryTreeModel node1 = new BinaryTreeModel("node1");
+        BinaryTreeModel node2 = new BinaryTreeModel("node2");
+        root.setLeft(node1);
+        root.setRight(node2);
+         
+        BinaryTreeModel node3 = new BinaryTreeModel("node3");
+        BinaryTreeModel node4 = new BinaryTreeModel("node4");
+        node1.setLeft(node3);
+        node1.setRight(node4);
+         
+        node2.setLeft(new BinaryTreeModel("node5"));
+        node2.setRight(new BinaryTreeModel("node6"));
+         
+        BinaryTreeModel node7 = new BinaryTreeModel("node7");
+        node3.setLeft(node7);
+        node7.setLeft(new BinaryTreeModel("node8"));
+        node7.setRight(new BinaryTreeModel("node9"));
+        
+        return root;
+    }
+
+    private BinaryTreeModel createLeftUnbalancedTree() {
+
+        BinaryTreeModel root = new BinaryTreeModel("root");
+
+        BinaryTreeModel node1 = new BinaryTreeModel("node1");
+        root.setLeft(node1);
+        root.setRight(new BinaryTreeModel("node2"));
+        
+        BinaryTreeModel node3 = new BinaryTreeModel("node3");
+        node1.setLeft(node3);
+        
+        BinaryTreeModel node4 = new BinaryTreeModel("node4");
+        node3.setLeft(node4);
+        
+        BinaryTreeModel node5 = new BinaryTreeModel("node5");
+        node4.setLeft(node5);
+        
+        BinaryTreeModel node6 = new BinaryTreeModel("node6");
+        node5.setLeft(node6);
+        
+        BinaryTreeModel node7 = new BinaryTreeModel("node7");
+        node6.setLeft(node7);
+        
+        node7.setLeft(new BinaryTreeModel("node8"));
+
+        return root;
+    }
+
+    private BinaryTreeModel createRightUnbalancedTree() {
+
+        BinaryTreeModel root = new BinaryTreeModel("root");
+
+        BinaryTreeModel node2 = new BinaryTreeModel("node2");
+        root.setLeft(new BinaryTreeModel("node1"));
+        root.setRight(node2);
+        
+        BinaryTreeModel node3 = new BinaryTreeModel("node3");
+        node2.setRight(node3);
+        
+        BinaryTreeModel node4 = new BinaryTreeModel("node4");
+        node3.setRight(node4);
+        
+        BinaryTreeModel node5 = new BinaryTreeModel("node5");
+        node4.setRight(node5);
+        
+        BinaryTreeModel node6 = new BinaryTreeModel("node6");
+        node5.setRight(node6);
+        
+        BinaryTreeModel node7 = new BinaryTreeModel("node7");
+        node6.setRight(node7);
+        
+        node7.setRight(new BinaryTreeModel("node8"));
+
+        return root;
+    }
+
+    @Test
+    public void givenBinaryTreeModelBalanced_whenPrintWithBinaryTreePrinter_thenProduceCorrectOutput() {
+        
+        StringBuilder expected = new StringBuilder();
+        expected.append("root").append("\n");
+        expected.append("├──node1").append("\n");
+        expected.append("│  ├──node3").append("\n");
+        expected.append("│  │  └──node7").append("\n");
+        expected.append("│  │     ├──node8").append("\n");
+        expected.append("│  │     └──node9").append("\n");
+        expected.append("│  └──node4").append("\n");
+        expected.append("└──node2").append("\n");
+        expected.append("   ├──node5").append("\n");
+        expected.append("   └──node6");
+        
+        new BinaryTreePrinter(balanced).print(System.out);
+        
+        assertEquals(expected.toString(), output.toString());
+    }
+
+    @Test
+    public void givenBinaryTreeModelLeftUnbalanced_whenPrintWithBinaryTreePrinter_thenProduceCorrectOutput() {
+        
+        StringBuilder expected = new StringBuilder();
+        expected.append("root").append("\n");
+        expected.append("├──node1").append("\n");
+        expected.append("│  └──node3").append("\n");
+        expected.append("│     └──node4").append("\n");
+        expected.append("│        └──node5").append("\n");
+        expected.append("│           └──node6").append("\n");
+        expected.append("│              └──node7").append("\n");
+        expected.append("│                 └──node8").append("\n");
+        expected.append("└──node2");
+        
+        new BinaryTreePrinter(leftSkewed).print(System.out);
+        
+        assertEquals(expected.toString(), output.toString());
+    }
+
+    @Test
+    public void givenBinaryTreeModelRightUnbalanced_whenPrintWithBinaryTreePrinter_thenProduceCorrectOutput() {
+        
+        StringBuilder expected = new StringBuilder();
+        expected.append("root").append("\n");
+        expected.append("├──node1").append("\n");
+        expected.append("└──node2").append("\n");
+        expected.append("   └──node3").append("\n");
+        expected.append("      └──node4").append("\n");
+        expected.append("         └──node5").append("\n");
+        expected.append("            └──node6").append("\n");
+        expected.append("               └──node7").append("\n");
+        expected.append("                  └──node8");
+        
+        new BinaryTreePrinter(rightSkewed).print(System.out);
+        
+        assertEquals(expected.toString(), output.toString());
+    }
+
+}

gson/src/main/java/com/baeldung/gson/entities/ActorGson.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.entities;
+package com.baeldung.gson.entities;
 
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;

gson/src/main/java/com/baeldung/gson/entities/Animal.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.entities;
+package com.baeldung.gson.entities;
 
 public abstract class Animal {
     public String type = "Animal";

gson/src/main/java/com/baeldung/gson/entities/Cow.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.entities;
+package com.baeldung.gson.entities;
 
 public class Cow extends Animal {
     private String breed;

gson/src/main/java/com/baeldung/gson/entities/Dog.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.entities;
+package com.baeldung.gson.entities;
 
 public class Dog extends Animal {
     private String petName;

gson/src/main/java/com/baeldung/gson/entities/Employee.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.entities;
+package com.baeldung.gson.entities;
 
 public class Employee {
     private int id;

gson/src/main/java/com/baeldung/gson/entities/Movie.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.entities;
+package com.baeldung.gson.entities;
 
 import java.util.List;
 

gson/src/main/java/com/baeldung/gson/entities/MovieWithNullValue.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.entities;
+package com.baeldung.gson.entities;
 
 import com.google.gson.annotations.Expose;
 

gson/src/main/java/com/baeldung/gson/entities/MyClass.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.entities;
+package com.baeldung.gson.entities;
 
 import java.util.Objects;
 

gson/src/main/java/com/baeldung/gson/entities/User.java

@@ -1,19 +1,19 @@
-package org.baeldung.gson.entities;
-
-public class User {
-
-	private int id;
-	private String name;
-	private transient String nationality;
-
-	public User(int id, String name, String nationality) {
-		this.id = id;
-		this.name = name;
-		this.nationality = nationality;
-	}
-
-	public User(int id, String name) {
-		this(id, name, null);
-	}
-
-}
+package com.baeldung.gson.entities;
+
+public class User {
+
+	private int id;
+	private String name;
+	private transient String nationality;
+
+	public User(int id, String name, String nationality) {
+		this.id = id;
+		this.name = name;
+		this.nationality = nationality;
+	}
+
+	public User(int id, String name) {
+		this(id, name, null);
+	}
+
+}

gson/src/main/java/com/baeldung/gson/entities/Weather.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.entities;
+package com.baeldung.gson.entities;
 
 import com.google.gson.annotations.SerializedName;
 

gson/src/main/java/com/baeldung/gson/primitives/models/BooleanExample.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.primitives.models;
+package com.baeldung.gson.primitives.models;
 
 public class BooleanExample {
     public boolean value;

gson/src/main/java/com/baeldung/gson/primitives/models/ByteExample.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.primitives.models;
+package com.baeldung.gson.primitives.models;
 
 public class ByteExample {
     public byte value = (byte) 1;

gson/src/main/java/com/baeldung/gson/primitives/models/CharExample.java

@@ -1,4 +1,4 @@
-package org.baeldung.gson.primitives.models;
+package com.baeldung.gson.primitives.models;
 
 public class CharExample {
     public char value;