diff --git a/Java/README.md b/Java/README.md
index 2ab86de..923c18a 100644
--- a/Java/README.md
+++ b/Java/README.md
@@ -13,6 +13,8 @@ ___
 * [Can_You_Access](pdf/can-you-access.pdf) - [Solution](java/Can_You_Access.java)
 * [Covariant_Return_Types](pdf/java-covariance.pdf) - [Solution](java/Covariant_Return_Types.java)
 * [Factory_pattern](pdf/java-factory.pdf) - [Solution](java/Factory_pattern.java)
+* [MD5](pdf/java-md5.pdf) - [Solution](java/MD5.java)
+* [SHA256](pdf/sha-256.pdf) - [Solution](java/SHA256.java)
 * [Varargs_Simple_Addition](pdf/simple-addition-varargs.pdf) - [Solution](java/Varargs_Simple_Addition.java)
 ___
 ### Big Number
@@ -66,6 +68,7 @@ ___
 ___
 ### Strings
 * [Anagrams](pdf/java-anagrams.pdf) - [Solution](java/Anagrams.java)
+* [Duplicate_words](pdf/duplicate-word.pdf) - [Solution](java/DuplicateWords.java)
 * [Pattern_syntax_checker](pdf/pattern-syntax-checker.pdf) - [Solution](java/Pattern_syntax_checker.java)
 * [Regex](pdf/java-regex.pdf) - [Solution](java/Regex.java)
 * [String_compare](pdf/java-string_compare.pdf) - [Solution](/java/String_compare.java)
diff --git a/Java/java/DuplicateWords.java b/Java/java/DuplicateWords.java
new file mode 100644
index 0000000..49c1911
--- /dev/null
+++ b/Java/java/DuplicateWords.java
@@ -0,0 +1,31 @@
+import java.util.Scanner;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class DuplicateWords {
+
+    public static void main(String[] args) {
+
+        String regex = "\\b([A-Za-z]+)\\b(\\s+\\1\\b)+";
+        Pattern p = Pattern.compile(regex, Pattern.CASE_INSENSITIVE);
+
+        Scanner in = new Scanner(System.in);
+        int numSentences = Integer.parseInt(in.nextLine());
+
+        while (numSentences-- > 0) {
+            String input = in.nextLine();
+
+            Matcher m = p.matcher(input);
+
+            // Check for subsequences of input that match the compiled pattern
+            while (m.find()) {
+                input = input.replaceAll(m.group(), m.group(1));
+            }
+
+            // Prints the modified sentence.
+            System.out.println(input);
+        }
+
+        in.close();
+    }
+}
\ No newline at end of file
diff --git a/Java/java/MD5.java b/Java/java/MD5.java
new file mode 100644
index 0000000..848d986
--- /dev/null
+++ b/Java/java/MD5.java
@@ -0,0 +1,19 @@
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Scanner;
+import javax.xml.bind.DatatypeConverter;
+
+public class MD5 {
+
+    public static void main(String[] args) {
+        Scanner in = new Scanner(System.in);
+        try {
+            MessageDigest md5 = MessageDigest.getInstance("MD5");
+            String input = in.nextLine();
+            System.out.println(DatatypeConverter.printHexBinary(md5.digest(input.getBytes())).toLowerCase());
+        } catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException("Invalid hashing algorithm");
+        }
+        in.close();
+    }
+}
diff --git a/Java/java/SHA256.java b/Java/java/SHA256.java
new file mode 100644
index 0000000..2072e6a
--- /dev/null
+++ b/Java/java/SHA256.java
@@ -0,0 +1,19 @@
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Scanner;
+import javax.xml.bind.DatatypeConverter;
+
+public class SHA256 {
+
+    public static void main(String[] args) {
+        Scanner in = new Scanner(System.in);
+        try {
+            MessageDigest sha256 = MessageDigest.getInstance("SHA-256");
+            String input = in.nextLine();
+            System.out.println(DatatypeConverter.printHexBinary(sha256.digest(input.getBytes())).toLowerCase());
+        } catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException("Invalid hashing algorithm");
+        }
+        in.close();
+    }
+}
diff --git a/Java/pdf/duplicate-word.pdf b/Java/pdf/duplicate-word.pdf
new file mode 100644
index 0000000..1360f10
Binary files /dev/null and b/Java/pdf/duplicate-word.pdf differ
diff --git a/Java/pdf/java-md5.pdf b/Java/pdf/java-md5.pdf
new file mode 100644
index 0000000..552eec1
Binary files /dev/null and b/Java/pdf/java-md5.pdf differ
diff --git a/Java/pdf/sha-256.pdf b/Java/pdf/sha-256.pdf
new file mode 100644
index 0000000..87a80ec
Binary files /dev/null and b/Java/pdf/sha-256.pdf differ
diff --git a/Regex/README.md b/Regex/README.md
index 2ae4623..b68cb45 100644
--- a/Regex/README.md
+++ b/Regex/README.md
@@ -51,7 +51,7 @@ Problem | Java | Javascript | Python
 [Backreferences_To_Failed_Groups](pdf/backreferences-to-failed-groups.pdf) | [Solution](java/Backreferences_To_Failed_Groups.java) | N/A | N/A
 [Branch_Reset_Groups](pdf/branch-reset-groups.pdf) | [Solution](java/Branch_Reset_Groups.java) | N/A | N/A
 [Forward_References](pdf/forward-references.pdf) | [Solution](java/Forward_References.java) | N/A | N/A
-[Mathcing_Same_Text_Again_Again](pdf/matching-same-text-again-again.pdf) | [Solution](java/Matching_Same_Text_Again_Again.java) | N/A | N/A
+[Matching_Same_Text_Again_Again](pdf/matching-same-text-again-again.pdf) | [Solution](java/Matching_Same_Text_Again_Again.java) | N/A | N/A
 ___
 ### Assertions
 Problem | Java | Javascript | Python