diff --git a/Roadmap/26 - SOLID SRP/java/simonguzman.java b/Roadmap/26 - SOLID SRP/java/simonguzman.java
new file mode 100644
index 0000000000..e0ececa33f
--- /dev/null
+++ b/Roadmap/26 - SOLID SRP/java/simonguzman.java	
@@ -0,0 +1,354 @@
+
+import java.io.FileWriter;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public class simonguzman {
+    public static void main(String[] args) {
+        //incorrectSrp();
+        //correctSrp();
+        //additionalExerciseNoSrp();
+        additionalExerciseSrp();
+    }
+    /****************************** Ejercicio adicional(Con srp) ******************************/
+    public static void additionalExerciseSrp(){
+        BookManager bookManager = new BookManager();
+        UserManager userManager = new UserManager();
+        LoanManager loanManager = new LoanManager();
+
+        bookManager.registerBook("1984", "George Orwell", 3);
+        userManager.registerUser("John Doe", "001", "johndoe@example.com");
+
+        User user = userManager.findUserById("001");
+        Book book = bookManager.findBookByTitle("1984");
+
+        loanManager.borrowBook(user, book);
+        loanManager.returnBook(user, book);
+    }
+
+    class BookSrp {
+        private String title;
+        private String author;
+        private int copies;
+    
+        public BookSrp(){
+
+        }
+
+        public BookSrp(String title, String author, int copies) {
+            this.title = title;
+            this.author = author;
+            this.copies = copies;
+        }
+    
+        public String getTitle() {
+            return title;
+        }
+    
+        public int getCopies() {
+            return copies;
+        }
+    
+        public void setCopies(int copies) {
+            this.copies = copies;
+        }
+    }
+    
+    class UserSrp {
+        private String name;
+        private String id;
+        private String email;
+    
+        public UserSrp(){
+
+        }
+
+        public UserSrp(String name, String id, String email) {
+            this.name = name;
+            this.id = id;
+            this.email = email;
+        }
+    
+        public String getName() {
+            return name;
+        }
+    
+        public String getId() {
+            return id;
+        }
+    }
+    
+    static class BookManager{
+        private List<Book> books = new ArrayList<>();
+        
+        public void registerBook(String title, String author, int copies){
+            books.add(new Book(title, author, copies));
+            System.out.println("Libro registrado: " + title);
+        }
+
+        public Book findBookByTitle(String title){
+            return books.stream().filter(b -> b.getTitle().equals(title)).findFirst().orElse(null);
+        }
+    }
+
+    static class UserManager{
+        private List<User> users = new ArrayList<>();
+
+        public void registerUser(String name, String id, String email){
+            users.add(new User(name, id, email));
+            System.out.println("Usuario registrado: " + name);
+        }
+
+        public User findUserById(String id){
+            return users.stream().filter(u -> u.getId().equals(id)).findFirst().orElse(null);
+        }
+    }
+
+    static class LoanManager{
+        private Map<User, List<Book>> borrowedBooks = new HashMap<>();
+
+        public void borrowBook(User user, Book book) {
+            if (book != null && book.getCopies() > 0) {
+                borrowedBooks.computeIfAbsent(user, k -> new ArrayList<>()).add(book);
+                book.setCopies(book.getCopies() - 1);
+                System.out.println("Libro prestado: " + book.getTitle() + " a " + user.getName());
+            } else {
+                System.out.println("No se pudo procesar el préstamo.");
+            }
+        }
+
+        public void returnBook(User user, Book book) {
+            List<Book> borrowed = borrowedBooks.get(user);
+            if (borrowed != null && borrowed.contains(book)) {
+                borrowed.remove(book);
+                book.setCopies(book.getCopies() + 1);
+                System.out.println("Libro devuelto: " + book.getTitle());
+            } else {
+                System.out.println("No se pudo devolver el libro.");
+            }
+        }
+    }
+
+    /****************************** Ejercicio adicional(Sin srp) ******************************/
+    public static void additionalExerciseNoSrp(){
+        Library library = new Library();
+
+        library.registerBook("1984", "George Orwell", 3);
+        library.registerUser("John Doe", "001", "johndoe@example.com");
+
+        library.borrowBook("001", "1984");
+        library.returnBook("001", "1984");
+    }
+
+    static class Library{
+        private List<Book> books = new ArrayList<>();
+        private List<User> users = new ArrayList<>();
+        private Map<User, List<Book>> borrowedBooks = new HashMap<>();
+
+        public void registerBook(String title, String author, int copies){
+            books.add(new Book(title, author, copies));
+            System.out.println("Libro registrado: "+title);
+        }
+
+        public void registerUser(String name, String id, String email){
+            users.add(new User(name, id, email));
+            System.out.println("Usuario registrado: "+name);
+        }
+
+        public void borrowBook(String userId, String bookTitle){
+            User user = users.stream().filter(u -> u.getId().equals(userId)).findFirst().orElse(null);
+            Book book = books.stream().filter(b -> b.getTitle().equals(bookTitle)).findFirst().orElse(null);
+
+            if(user != null && book != null && book.getCopies() > 0){
+                borrowedBooks.computeIfAbsent(user, k -> new ArrayList<>()).add(book);
+                book.setCopies(book.getCopies()-1);
+                System.out.println("Libro prestado: " + bookTitle + " a " + user.getName());
+            }else{
+                System.out.println("No se pudo procesar el prestamo.");
+            }
+        }
+
+        public void returnBook(String userId, String bookTitle){
+            User user = users.stream().filter(u -> u.getId().equals(userId)).findFirst().orElse(null);
+            List<Book> borrowed = borrowedBooks.get(user); 
+
+            if(borrowed != null){
+                Book book = borrowed.stream().filter(b -> b.getTitle().equals(bookTitle)).findFirst().orElse(null);
+                if(book != null){
+                    borrowed.remove(book);
+                    book.setCopies(book.getCopies() + 1);
+                    System.out.println("Libro devuelto: "+bookTitle);
+                }
+            }else{
+                System.out.println("ERROR: No se pudo devolver el libro.");
+            }
+        }
+    }
+
+    static class Book{
+        private String title;
+        private String author;
+        private int copies;
+
+        public Book(){
+
+        }
+
+        public Book(String title, String author, int copies){
+            this.title = title;
+            this.author = author;
+            this.copies = copies;
+        }
+
+        public String getTitle() {
+            return title;
+        }
+
+        public int getCopies() {
+            return copies;
+        }
+
+        public void setCopies(int copies) {
+            this.copies = copies;
+        }
+
+    }
+
+    static class User{
+        private String name;
+        private String id;
+        private String email;
+
+        public User(){
+
+        }
+
+        public User(String name, String id, String email){
+            this.name = name;
+            this.id = id;
+            this.email = email;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public String getId() {
+            return id;
+        }
+
+        public String getEmail() {
+            return email;
+        }
+    }
+
+    /****************************** ejemplo con srp(Correcto) ******************************/
+    public static void correctSrp() {
+        InvoiceSrp invoice = new InvoiceSrp("Laptop",2,1200.00);
+
+        InvoicePrinter printer = new InvoicePrinter();
+        printer.printInvoice(invoice);
+
+        InvoiceSaver saver = new InvoiceSaver();
+        saver.saveToFile(invoice);
+    }
+    static class InvoiceSrp{
+        private String product;
+        private int quantity;
+        private double price;
+
+        public InvoiceSrp(){
+            
+        }
+
+        public InvoiceSrp(String product, int quantity, double price){
+            this.product = product;
+            this.quantity = quantity;
+            this.price = price;
+        }
+
+        public double calculateTotal(){
+            return quantity * price;
+        }
+
+        public String getProduct() {
+            return product;
+        }
+
+        public int getQuantity() {
+            return quantity;
+        }
+
+        public double getPrice() {
+            return price;
+        }
+    }
+
+    static class InvoicePrinter {
+        public void printInvoice(InvoiceSrp invoice){
+            System.out.println("Producto: "+invoice.getProduct());
+            System.out.println("Cantidad: "+invoice.getQuantity());
+            System.out.println("Precio: "+invoice.getPrice());
+            System.out.println("Total: "+invoice.calculateTotal());
+        }
+    }
+
+    static class InvoiceSaver{
+        public void saveToFile(InvoiceSrp invoice){
+            try (FileWriter writer = new FileWriter("invoice.txt")){
+                writer.write("Producto: " + invoice.getProduct() + "\n");
+                writer.write("Cantidad: " + invoice.getQuantity() + "\n");
+                writer.write("Precio unitario: " + invoice.getPrice() + "\n");
+                writer.write("Total: " + invoice.calculateTotal() + "\n");
+            } catch (Exception e) {
+                System.out.println("ERROR: no se pudo generar la factura..."+e.getMessage());
+            }
+        }
+    }
+    /****************************** ejemplo sin srp(Incorrecto) ******************************/
+    public static void incorrectSrp(){
+        Invoice invoice = new Invoice("Laptop",2,1200.00);
+        invoice.printInvoice();
+        invoice.saveToFile();
+    }
+
+    static class Invoice{
+        private String product;
+        private int quantity;
+        private double price;
+
+        public Invoice(){
+
+        }
+
+        public Invoice(String product, int quantity, double price){
+            this.product = product;
+            this.quantity = quantity;
+            this.price = price;
+        }
+
+        public double calculateTotal(){
+            return quantity * price;
+        }
+
+        public void printInvoice(){
+            System.out.println("Producto: "+product);
+            System.out.println("Cantidad: "+quantity);
+            System.out.println("Precio: "+price);
+            System.out.println("Total: "+calculateTotal());
+        }
+        
+        public void saveToFile(){
+            try (FileWriter writer = new FileWriter("invoice.txt")){
+                writer.write("Producto: " + product + "\n");
+                writer.write("Cantidad: " + quantity + "\n");
+                writer.write("Precio Unitario: " + price + "\n");
+                writer.write("Total: " + calculateTotal() + "\n");
+            } catch (Exception e) {
+                System.out.println("Error al guardar la factura: "+e.getMessage());
+            }
+        }
+    }
+}
diff --git a/Roadmap/27 - SOLID OCP/java/simonguzman.java b/Roadmap/27 - SOLID OCP/java/simonguzman.java
new file mode 100644
index 0000000000..8e5c88f8b7
--- /dev/null
+++ b/Roadmap/27 - SOLID OCP/java/simonguzman.java	
@@ -0,0 +1,261 @@
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class simonguzman {
+    public static void main(String[] args) {
+        libraryViolationOcp();
+        libraryFollowOCP();
+        calculatorTest();
+        calculatorOCPTest();
+    }
+    /*************************** Ejercicio adicional con ocp(Correcto) ***************************/
+    static void calculatorOCPTest(){
+        CalculatorOCP calculator = new CalculatorOCP();
+
+        double resultAdd = calculator.Calculate(new Addition(), 10, 5);
+        System.out.println("Suma: " + resultAdd);
+
+        double resultSub = calculator.Calculate(new Subtraction(), 10, 5);
+        System.out.println("Resta: " + resultSub);
+
+        double resultMul = calculator.Calculate(new Multiplication(), 10, 5);
+        System.out.println("Multiplicación: " + resultMul);
+
+        double resultDiv = calculator.Calculate(new Division(), 10, 5);
+        System.out.println("División: " + resultDiv);
+
+        double resultPow = calculator.Calculate(new Power(), 2, 3);
+        System.out.println("Potencia: " + resultPow);
+    }
+    interface Operation{
+        double function(double num1, double num2);
+    }
+
+    static class Addition implements Operation{
+        @Override
+        public double function(double num1, double num2) {
+            return num1 + num2; 
+        }
+    }
+
+    static class Subtraction implements Operation{
+        @Override
+        public double function(double num1, double num2) {
+            return num1 - num2;
+        }  
+    }
+
+    static class Multiplication implements Operation{
+        @Override
+        public double function(double num1, double num2) {
+            return num1 * num2;
+        }  
+    }
+
+    static class Division implements Operation{
+        @Override
+        public double function(double num1, double num2) {
+            return num1 /  num2;
+        }      
+    }
+
+    static class Power implements Operation{
+        @Override
+        public double function(double num1, double num2) {
+            return Math.pow(num1, num2);
+        }
+    }
+
+    static class CalculatorOCP{
+        public double Calculate(Operation operation, double num1, double num2){
+            return operation.function(num1, num2);
+        }
+    }
+
+
+    /*************************** Ejercicio adicional sin ocp(Incorrecto) ***************************/
+    static void calculatorTest(){
+        Calculator calculator = new Calculator();
+
+        double resultAdd = calculator.calculate("sum", 10, 5);
+        System.out.println("Suma: " + resultAdd);
+
+        double resultSub = calculator.calculate("substract", 10, 5);
+        System.out.println("Resta: " + resultSub);
+
+        double resultMul = calculator.calculate("multiply", 10, 5);
+        System.out.println("Multiplicación: " + resultMul);
+
+        double resultDiv = calculator.calculate("divide", 10, 5);
+        System.out.println("División: " + resultDiv);
+
+        try {
+            double resultPow = calculator.calculate("power", 2, 3);
+            System.out.println("Potencia: " + resultPow);
+        } catch (UnsupportedOperationException e) {
+            System.out.println("Error: " + e.getMessage());
+        }
+    }
+
+    static class Calculator{
+        public double calculate(String operation, double num1, double num2){
+            switch (operation) {
+                case "sum": return  num1 + num2; 
+                case "substract": return  num1 - num2; 
+                case "multiply": return  num1 * num2; 
+                case "divide": return  num1 / num2; 
+                default:
+                    throw new UnsupportedOperationException("Operacion no soportada");
+            }
+        }
+    }
+
+    /*************************** Ejemplo con ocp(Correcto) ***************************/
+    static void libraryFollowOCP(){
+        List<String> books = new ArrayList<>();
+        List<String> users = new ArrayList<>();
+        LibraryOcp library = new LibraryOcp();
+
+        LibraryOperation registerBook = new RegisterBookOperation("El Quijote", books);
+        library.performOperation(registerBook);
+
+        LibraryOperation registerUser = new RegisterUserOperation("Juan Perez", users);
+        library.performOperation(registerUser);
+
+        LibraryOperation loanBook = new LoanBookOperation("El Quijote", "Juan Perez", books);
+        library.performOperation(loanBook);
+
+        LibraryOperation renewLoan = new RenewLoanOperation("El Quijote", "Juan Perez");
+        library.performOperation(renewLoan);
+    }
+
+    interface LibraryOperation{
+        void execute();
+    }
+
+    static class RegisterBookOperation implements LibraryOperation{
+        private String book;
+        private List<String> books;
+
+        public RegisterBookOperation(){
+            
+        }
+
+        public RegisterBookOperation(String book, List<String> books){
+            this.book = book;
+            this.books = books;
+        }
+
+        @Override
+        public void execute() {
+            books.add(book);
+            System.out.println("Libro registrado: " + book);
+        }
+    }
+
+    static class RegisterUserOperation implements LibraryOperation{
+        private String user;
+        private List<String> users;
+
+        public RegisterUserOperation(){
+
+        }
+
+        public RegisterUserOperation(String user, List<String> users){
+            this.user = user;
+            this.users = users;
+        }
+        @Override
+        public void execute() {
+            users.add(user);
+            System.out.println("Usuario registrado: "+user);
+        }
+    }
+
+    static class LoanBookOperation implements LibraryOperation{
+        private String book;
+        private String user;
+        private List<String> books;
+
+        public LoanBookOperation(){
+
+        }
+
+        public LoanBookOperation(String book, String user, List<String> books){
+            this.book = book;
+            this.user = user;
+            this.books = books;
+        }
+
+        @Override
+        public void execute() {
+            if(books.contains(book)){
+                System.out.println("Libro: " + book + " usuario " + user);
+            }else{
+                System.out.println("El libro no esta disponible.");
+            }
+        }
+        
+    }
+
+    static class RenewLoanOperation implements LibraryOperation{
+        private String book;
+        private String user;
+
+        public RenewLoanOperation(){
+
+        }
+
+        public RenewLoanOperation(String book, String user){
+            this.book = book;
+            this.user = user;
+        }
+
+        @Override
+        public void execute() {
+            System.out.println("El prestamo del libro " + book + " a sido renovado por " + user);
+        }
+    }
+
+    static class LibraryOcp{
+        public void performOperation(LibraryOperation operation){
+            operation.execute();
+        }
+    }
+    /*************************** Ejemplo sin ocp(Incorrecto) ***************************/
+    static void libraryViolationOcp(){
+        Library library = new Library();
+        library.registerBook("El quijote");
+        library.registerUser("Juan Perez");
+        library.loanBook("El quijote", "Juan Perez");
+        library.returnBook("El quijote", "Juan Perez");
+    }
+
+    static class Library{
+        private List<String> books = new ArrayList<>();
+        private List<String> users = new ArrayList<>();
+
+        public void registerBook(String book){
+            books.add(book);
+            System.out.println("Libro registrado: " + book);
+        }
+
+        public void registerUser(String user){
+            users.add(user);
+            System.out.println("Usuario registrado: "+user);
+        }
+
+        public void loanBook(String book, String user){
+            if(books.contains(book)){
+                System.out.println("Libro: " + book + " prestado a " + user);
+            }else{
+                System.out.println("El libro no esta disponible");
+            }
+        }
+
+        public void returnBook(String book, String user){
+            System.out.println("Libro: " + book + " devuelto por " + user);
+        }
+    }
+}