Merge branch 'master' into pr/873-yassser

Conflicts:
	core-java/src/main/java/com/baeldung/generics/Generics.java
	core-java/src/test/java/com/baeldung/generics/GenericsTest.java

core-java/src/main/java/com/baeldung/hashing/SHA256Hashing.java

@@ -1,6 +1,5 @@
 package com.baeldung.hashing;
 
-
 import com.google.common.hash.Hashing;
 import org.apache.commons.codec.digest.DigestUtils;
 import org.bouncycastle.util.encoders.Hex;
@@ -11,17 +10,14 @@ import java.security.NoSuchAlgorithmException;
 
 public class SHA256Hashing {
 
-    public static String HashWithJavaMessageDigest(final String originalString)
-            throws NoSuchAlgorithmException {
+    public static String HashWithJavaMessageDigest(final String originalString) throws NoSuchAlgorithmException {
         final MessageDigest digest = MessageDigest.getInstance("SHA-256");
-        final byte[] encodedhash = digest.digest(
-                originalString.getBytes(StandardCharsets.UTF_8));
+        final byte[] encodedhash = digest.digest(originalString.getBytes(StandardCharsets.UTF_8));
         return bytesToHex(encodedhash);
     }
 
     public static String HashWithGuava(final String originalString) {
-        final String sha256hex = Hashing.sha256().hashString(
-                originalString, StandardCharsets.UTF_8).toString();
+        final String sha256hex = Hashing.sha256().hashString(originalString, StandardCharsets.UTF_8).toString();
         return sha256hex;
     }
 
@@ -30,11 +26,9 @@ public class SHA256Hashing {
         return sha256hex;
     }
 
-    public static String HashWithBouncyCastle(final String originalString)
-            throws NoSuchAlgorithmException {
+    public static String HashWithBouncyCastle(final String originalString) throws NoSuchAlgorithmException {
         final MessageDigest digest = MessageDigest.getInstance("SHA-256");
-        final byte[] hash = digest.digest(
-                originalString.getBytes(StandardCharsets.UTF_8));
+        final byte[] hash = digest.digest(originalString.getBytes(StandardCharsets.UTF_8));
         final String sha256hex = new String(Hex.encode(hash));
         return sha256hex;
     }
@@ -43,7 +37,8 @@ public class SHA256Hashing {
         StringBuffer hexString = new StringBuffer();
         for (int i = 0; i < hash.length; i++) {
             String hex = Integer.toHexString(0xff & hash[i]);
-            if(hex.length() == 1) hexString.append('0');
+            if (hex.length() == 1)
+                hexString.append('0');
             hexString.append(hex);
         }
         return hexString.toString();

core-java/src/main/java/com/baeldung/java/nio2/visitor/FileSearchExample.java

@@ -0,0 +1,56 @@
+package com.baeldung.java.nio2.visitor;
+
+import java.io.IOException;
+import java.nio.file.*;
+import java.nio.file.attribute.BasicFileAttributes;
+
+import static java.nio.file.FileVisitResult.CONTINUE;
+import static java.nio.file.FileVisitResult.TERMINATE;
+
+public class FileSearchExample implements FileVisitor<Path> {
+    private final String fileName;
+    private final Path startDir;
+
+    public FileSearchExample(String fileName, Path startingDir) {
+        this.fileName = fileName;
+        startDir = startingDir;
+    }
+
+    @Override
+    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
+        return CONTINUE;
+    }
+
+    @Override
+    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
+        String fileName = file.getFileName().toString();
+        if (this.fileName.equals(fileName)) {
+            System.out.println("File found: " + file.toString());
+            return TERMINATE;
+        }
+        return CONTINUE;
+    }
+
+    @Override
+    public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
+        System.out.println("Failed to access file: " + file.toString());
+        return CONTINUE;
+    }
+
+    @Override
+    public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
+        boolean finishedSearch = Files.isSameFile(dir, startDir);
+        if (finishedSearch) {
+            System.out.println("File:" + fileName + " not found");
+            return TERMINATE;
+        }
+        return CONTINUE;
+    }
+
+    public static void main(String[] args) throws IOException {
+        Path startingDir = Paths.get("C:/Users/new/Desktop");
+        FileSearchExample crawler = new FileSearchExample("hibernate.txt", startingDir);
+        Files.walkFileTree(startingDir, crawler);
+    }
+
+}

core-java/src/main/java/com/baeldung/java/nio2/visitor/FileVisitorImpl.java

@@ -0,0 +1,30 @@
+package com.baeldung.java.nio2.visitor;
+
+import java.io.IOException;
+import java.nio.file.FileVisitResult;
+import java.nio.file.FileVisitor;
+import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
+
+public class FileVisitorImpl implements FileVisitor<Path> {
+
+    @Override
+    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) {
+        return null;
+    }
+
+    @Override
+    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) {
+        return null;
+    }
+
+    @Override
+    public FileVisitResult visitFileFailed(Path file, IOException exc) {
+        return null;
+    }
+
+    @Override
+    public FileVisitResult postVisitDirectory(Path dir, IOException exc) {
+        return null;
+    }
+}

core-java/src/main/java/com/baeldung/java/nio2/watcher/DirectoryWatcherExample.java

@@ -0,0 +1,25 @@
+package com.baeldung.java.nio2.watcher;
+
+import java.io.IOException;
+import java.nio.file.FileSystems;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardWatchEventKinds;
+import java.nio.file.WatchEvent;
+import java.nio.file.WatchKey;
+import java.nio.file.WatchService;
+
+public class DirectoryWatcherExample {
+    public static void main(String[] args) throws IOException, InterruptedException {
+        WatchService watchService = FileSystems.getDefault().newWatchService();
+        Path path = Paths.get(System.getProperty("user.home"));
+        path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE, StandardWatchEventKinds.ENTRY_DELETE, StandardWatchEventKinds.ENTRY_MODIFY);
+        WatchKey key;
+        while ((key = watchService.take()) != null) {
+            for (WatchEvent<?> event : key.pollEvents()) {
+                System.out.println("Event kind:" + event.kind() + ". File affected: " + event.context() + ".");
+            }
+            key.reset();
+        }
+    }
+}

core-java/src/main/java/com/baeldung/java_8_features/Person.java

@@ -0,0 +1,39 @@
+package com.baeldung.java_8_features;
+
+import java.util.Optional;
+
+public class Person {
+    private String name;
+    private int age;
+    private String password;
+
+    public Person(String name, int age) {
+        this.name = name;
+        this.age = age;
+    }
+
+    public Optional<String> getName() {
+        return Optional.ofNullable(name);
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public Optional<Integer> getAge() {
+        return Optional.ofNullable(age);
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    public void setPassword(String password) {
+        this.password = password;
+    }
+
+    public Optional<String> getPassword() {
+        return Optional.ofNullable(password);
+    }
+
+}