diff --git a/src/main/java/com/staxrt/tutorial/controller/UserController.java b/src/main/java/com/staxrt/tutorial/controller/UserController.java
index 434e30c..091aa85 100644
--- a/src/main/java/com/staxrt/tutorial/controller/UserController.java
+++ b/src/main/java/com/staxrt/tutorial/controller/UserController.java
@@ -20,10 +20,17 @@
 
 package com.staxrt.tutorial.controller;
 
+import com.staxrt.tutorial.dto.PageResponseDto;
+import com.staxrt.tutorial.dto.UserDto;
+import com.staxrt.tutorial.dto.UserResponseDto;
 import com.staxrt.tutorial.exception.ResourceNotFoundException;
+import com.staxrt.tutorial.exception.UserAlreadyExistException;
 import com.staxrt.tutorial.model.User;
 import com.staxrt.tutorial.repository.UserRepository;
+import com.staxrt.tutorial.service.UserService;
+
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Page;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
@@ -32,6 +39,8 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 
 /**
  * The type User controller.
@@ -45,87 +54,82 @@ public class UserController {
   @Autowired
   private UserRepository userRepository;
 
+  @Autowired
+  UserService userService;
+
   /**
    * Get all users list.
    *
    * @return the list
    */
+  @GetMapping("/demo")
+  public String printHello() {
+    return "Hello World!";
+  }
+
   @GetMapping("/users")
-  public List<User> getAllUsers() {
-    return userRepository.findAll();
+  public ResponseEntity<List<User>> getAllUsers() {
+    return ResponseEntity.ok(userService.findAllUserse());
   }
 
   /**
    * Gets users by id.
    *
-   * @param userId the user id
+   * @Pathvaraible userId the user id
    * @return the users by id
    * @throws ResourceNotFoundException the resource not found exception
    */
   @GetMapping("/users/{id}")
-  public ResponseEntity<User> getUsersById(@PathVariable(value = "id") Long userId)
-      throws ResourceNotFoundException {
-    User user =
-        userRepository
-            .findById(userId)
-            .orElseThrow(() -> new ResourceNotFoundException("User not found on :: " + userId));
-    return ResponseEntity.ok().body(user);
+  public ResponseEntity<User> getUsersById(@PathVariable(value = "id") Long userId) {
+    return ResponseEntity.ok(userService.findByUserId(userId));
   }
 
   /**
    * Create user user.
    *
-   * @param user the user
+   * @RequestBody user
    * @return the user
    */
   @PostMapping("/users")
-  public User createUser(@Valid @RequestBody User user) {
-    return userRepository.save(user);
+  public ResponseEntity<UserResponseDto> createUser(@Valid @RequestBody UserDto user) {
+    return ResponseEntity.ok(userService.createUser(user));
   }
 
   /**
    * Update user response entity.
    *
-   * @param userId the user id
-   * @param userDetails the user details
+   * @RequestBody user the user id
+   * 
    * @return the response entity
    * @throws ResourceNotFoundException the resource not found exception
    */
   @PutMapping("/users/{id}")
-  public ResponseEntity<User> updateUser(
-      @PathVariable(value = "id") Long userId, @Valid @RequestBody User userDetails)
-      throws ResourceNotFoundException {
-
-    User user =
-        userRepository
-            .findById(userId)
-            .orElseThrow(() -> new ResourceNotFoundException("User not found on :: " + userId));
-
-    user.setEmail(userDetails.getEmail());
-    user.setLastName(userDetails.getLastName());
-    user.setFirstName(userDetails.getFirstName());
-    user.setUpdatedAt(new Date());
-    final User updatedUser = userRepository.save(user);
-    return ResponseEntity.ok(updatedUser);
+  public ResponseEntity<UserResponseDto> updateUser(
+      @PathVariable(value = "id") Long userId, @Valid @RequestBody UserDto userDetails) {
+
+    return ResponseEntity.ok(userService.updateuser(userId, userDetails));
   }
 
   /**
    * Delete user map.
    *
-   * @param userId the user id
+   * @Pathvaraible userId the user id
    * @return the map
    * @throws Exception the exception
    */
   @DeleteMapping("/user/{id}")
-  public Map<String, Boolean> deleteUser(@PathVariable(value = "id") Long userId) throws Exception {
-    User user =
-        userRepository
-            .findById(userId)
-            .orElseThrow(() -> new ResourceNotFoundException("User not found on :: " + userId));
-
-    userRepository.delete(user);
-    Map<String, Boolean> response = new HashMap<>();
-    response.put("deleted", Boolean.TRUE);
-    return response;
+  public ResponseEntity<Map<String, Boolean>> deleteUser(@PathVariable(value = "id") Long userId) {
+    return ResponseEntity.ok(userService.deleteUser(userId));
+  }
+
+  @GetMapping("/users/getPaginatedusers")
+  public ResponseEntity<PageResponseDto<UserResponseDto>> getPaginatedUsers(
+      @RequestParam(defaultValue = "0") int page,
+      @RequestParam(defaultValue = "5") int size,
+      @RequestParam(defaultValue = "id") String sortBy,
+      @RequestParam(defaultValue = "asc") String direction) {
+    PageResponseDto<UserResponseDto> users = userService.getUsers(page, size, sortBy, direction);
+    return ResponseEntity.ok(users);
+
   }
 }
diff --git a/src/main/java/com/staxrt/tutorial/dto/CreateGroup.java b/src/main/java/com/staxrt/tutorial/dto/CreateGroup.java
new file mode 100644
index 0000000..507ae67
--- /dev/null
+++ b/src/main/java/com/staxrt/tutorial/dto/CreateGroup.java
@@ -0,0 +1,5 @@
+package com.staxrt.tutorial.dto;
+
+public interface CreateGroup {
+
+}
diff --git a/src/main/java/com/staxrt/tutorial/dto/PageResponseDto.java b/src/main/java/com/staxrt/tutorial/dto/PageResponseDto.java
new file mode 100644
index 0000000..f1dba88
--- /dev/null
+++ b/src/main/java/com/staxrt/tutorial/dto/PageResponseDto.java
@@ -0,0 +1,70 @@
+package com.staxrt.tutorial.dto;
+
+import java.util.List;
+
+public class PageResponseDto<T> {
+
+    private List<T> data;
+    private int page;
+    private int size;
+    private long totalElements;     
+    private int totalPages;  
+    private boolean first;
+    private boolean last;
+    public PageResponseDto(List<T> data, int page, int size, long totalElements, int totalPages, boolean first,
+            boolean last) {
+        this.data = data;
+        this.page = page;
+        this.size = size;
+        this.totalElements = totalElements;
+        this.totalPages = totalPages;
+        this.first = first;
+        this.last = last;
+    }
+    public List<T> getData() {
+        return data;
+    }
+    public void setData(List<T> data) {
+        this.data = data;
+    }
+    public int getPage() {
+        return page;
+    }
+    public void setPage(int page) {
+        this.page = page;
+    }
+    public int getSize() {
+        return size;
+    }
+    public void setSize(int size) {
+        this.size = size;
+    }
+    public long getTotalElements() {
+        return totalElements;
+    }
+    public void setTotalElements(long totalElements) {
+        this.totalElements = totalElements;
+    }
+    public int getTotalPages() {
+        return totalPages;
+    }
+    public void setTotalPages(int totalPages) {
+        this.totalPages = totalPages;
+    }
+    public boolean isFirst() {
+        return first;
+    }
+    public void setFirst(boolean first) {
+        this.first = first;
+    }
+    public boolean isLast() {
+        return last;
+    }
+    public void setLast(boolean last) {
+        this.last = last;
+    }
+        
+    
+    
+
+}
diff --git a/src/main/java/com/staxrt/tutorial/dto/UpdateGroup.java b/src/main/java/com/staxrt/tutorial/dto/UpdateGroup.java
new file mode 100644
index 0000000..bce55c0
--- /dev/null
+++ b/src/main/java/com/staxrt/tutorial/dto/UpdateGroup.java
@@ -0,0 +1,5 @@
+package com.staxrt.tutorial.dto;
+
+public interface UpdateGroup {
+
+}
diff --git a/src/main/java/com/staxrt/tutorial/dto/UserDto.java b/src/main/java/com/staxrt/tutorial/dto/UserDto.java
new file mode 100644
index 0000000..d02df88
--- /dev/null
+++ b/src/main/java/com/staxrt/tutorial/dto/UserDto.java
@@ -0,0 +1,74 @@
+package com.staxrt.tutorial.dto;
+
+import javax.validation.constraints.Email;
+import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Size;
+
+public class UserDto {
+
+    @NotNull(message = "First name cannot be null")
+    @Size(min = 2, message = "First name should have at least 2 characters")
+    @Size(max = 50, message = "First name should have at most 50 characters")
+    private String firstName;
+
+    @NotNull(message = "Last name cannot be null")
+    @Size(min = 2, message = "Last name should have at least 2 characters")
+    @Size(max = 50, message = "Last name should have at most 50 characters")
+    private String lastName;
+
+    @NotNull(message = "Email cannot be null")
+    @Email(message = "Email should be valid")
+    @Size(max = 100, message = "Email should have at most 100 characters")
+    private String email;
+
+    public UserDto() {
+    }
+
+    public UserDto(@NotNull(message = "First name cannot be null") String firstName,
+            @NotNull(message = "Last name cannot be null") String lastName,
+            @NotNull(message = "Email cannot be null") @Email(message = "Email should be valid") String email
+) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.email = email;
+        
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    @Override
+    public String toString() {
+        return "UserDto [firstName=" + firstName + ", lastName=" + lastName + ", email=" + email + "]";
+    }
+
+  
+
+    
+
+
+
+
+
+}
diff --git a/src/main/java/com/staxrt/tutorial/dto/UserResponseDto.java b/src/main/java/com/staxrt/tutorial/dto/UserResponseDto.java
new file mode 100644
index 0000000..0f03d04
--- /dev/null
+++ b/src/main/java/com/staxrt/tutorial/dto/UserResponseDto.java
@@ -0,0 +1,51 @@
+package com.staxrt.tutorial.dto;
+
+import java.util.Date;
+
+public class UserResponseDto {
+    private Long id;
+    private String firstname;
+    private String lastName;
+    private String email;
+
+
+    
+   
+    public UserResponseDto() {
+    }
+   
+    public UserResponseDto(Long id, String firstname, String lastName, String email) {
+        this.id = id;
+        this.firstname = firstname;
+        this.lastName = lastName;
+        this.email = email;
+        
+    }
+    public Long getId() {
+        return id;
+    }
+    public void setId(Long id) {
+        this.id = id;
+    }
+    public String getFirstname() {
+        return firstname;
+    }
+    public void setFirstname(String firstname) {
+        this.firstname = firstname;
+    }
+    public String getLastName() {
+        return lastName;
+    }
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+    public String getEmail() {
+        return email;
+    }
+    public void setEmail(String email) {
+        this.email = email;
+    }
+    
+
+
+}
diff --git a/src/main/java/com/staxrt/tutorial/exception/ErrorResponse.java b/src/main/java/com/staxrt/tutorial/exception/ErrorResponse.java
index b3a7bb3..7de13e2 100644
--- a/src/main/java/com/staxrt/tutorial/exception/ErrorResponse.java
+++ b/src/main/java/com/staxrt/tutorial/exception/ErrorResponse.java
@@ -1,123 +1,33 @@
-/*
- *
- *  Copyright (c) 2018-2020 Givantha Kalansuriya, This source is a part of
- *   Staxrt - sample application source code.
- *   http://staxrt.com
- *
- *   Licensed under the Apache License, Version 2.0 (the "License");
- *   you may not use this file except in compliance with the License.
- *   You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *   Unless required by applicable law or agreed to in writing, software
- *   distributed under the License is distributed on an "AS IS" BASIS,
- *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *   See the License for the specific language governing permissions and
- *   limitations under the License.
- *
- */
-
 package com.staxrt.tutorial.exception;
-
-import java.util.Date;
-
-/**
- * The type Error response.
- *
- * @author Givantha Kalansuriya
- */
-public class ErrorResponse {
-
-  private Date timestamp;
-  private String status;
-  private String message;
-  private String details;
-
-  /**
-   * Instantiates a new Error response.
-   *
-   * @param timestamp the timestamp
-   * @param status the status
-   * @param message the message
-   * @param details the details
-   */
-  public ErrorResponse(Date timestamp, String status, String message, String details) {
-    this.timestamp = timestamp;
-    this.status = status;
-    this.message = message;
-    this.details = details;
-  }
-
-  /**
-   * Gets timestamp.
-   *
-   * @return the timestamp
-   */
-  public Date getTimestamp() {
-    return timestamp;
-  }
-
-  /**
-   * Sets timestamp.
-   *
-   * @param timestamp the timestamp
-   */
-  public void setTimestamp(Date timestamp) {
-    this.timestamp = timestamp;
-  }
-
-  /**
-   * Gets status.
-   *
-   * @return the status
-   */
-  public String getStatus() {
-    return status;
-  }
-
-  /**
-   * Sets status.
-   *
-   * @param status the status
-   */
-  public void setStatus(String status) {
-    this.status = status;
-  }
-
-  /**
-   * Gets message.
-   *
-   * @return the message
-   */
-  public String getMessage() {
-    return message;
-  }
-
-  /**
-   * Sets message.
-   *
-   * @param message the message
-   */
-  public void setMessage(String message) {
-    this.message = message;
-  }
-
-  /**
-   * Gets details.
-   *
-   * @return the details
-   */
-  public String getDetails() {
-    return details;
-  }
-
-  /**
-   * Sets details.
-   *
-   * @param details the details
-   */
-  public void setDetails(String details) {
-    this.details = details;
-  }
-}
+import java.time.LocalDateTime;
+
+public class ErrorResponse{
+    private String message;
+    private int statusCode;
+    private LocalDateTime timestamp;
+    public ErrorResponse(String message, int statusCode) {
+        this.message = message;
+        this.statusCode = statusCode;
+        this.timestamp = LocalDateTime.now();
+    }
+    public String getMessage() {
+        return message;
+    }
+    public void setMessage(String message) {
+        this.message = message;
+    }
+    public int getStatusCode() {
+        return statusCode;
+    }
+    public void setStatusCode(int statusCode) {
+        this.statusCode = statusCode;
+    }
+    public LocalDateTime getTimestamp() {
+        return timestamp;
+    }
+    public void setTimestamp(LocalDateTime timestamp) {
+        this.timestamp = timestamp;
+    }
+
+    
+}
\ No newline at end of file
diff --git a/src/main/java/com/staxrt/tutorial/exception/GlobalExceptionHandler.java b/src/main/java/com/staxrt/tutorial/exception/GlobalExceptionHandler.java
index 36940be..c510130 100644
--- a/src/main/java/com/staxrt/tutorial/exception/GlobalExceptionHandler.java
+++ b/src/main/java/com/staxrt/tutorial/exception/GlobalExceptionHandler.java
@@ -1,67 +1,93 @@
-/*
- *
- *  Copyright (c) 2018-2020 Givantha Kalansuriya, This source is a part of
- *   Staxrt - sample application source code.
- *   http://staxrt.com
- *
- *   Licensed under the Apache License, Version 2.0 (the "License");
- *   you may not use this file except in compliance with the License.
- *   You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *   Unless required by applicable law or agreed to in writing, software
- *   distributed under the License is distributed on an "AS IS" BASIS,
- *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *   See the License for the specific language governing permissions and
- *   limitations under the License.
- *
- */
+// /*
+//  *
+//  *  Copyright (c) 2018-2020 Givantha Kalansuriya, This source is a part of
+//  *   Staxrt - sample application source code.
+//  *   http://staxrt.com
+//  *
+//  *   Licensed under the Apache License, Version 2.0 (the "License");
+//  *   you may not use this file except in compliance with the License.
+//  *   You may obtain a copy of the License at
+//  *
+//  *      http://www.apache.org/licenses/LICENSE-2.0
+//  *
+//  *   Unless required by applicable law or agreed to in writing, software
+//  *   distributed under the License is distributed on an "AS IS" BASIS,
+//  *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  *   See the License for the specific language governing permissions and
+//  *   limitations under the License.
+//  *
+//  */
 
-package com.staxrt.tutorial.exception;
+ package com.staxrt.tutorial.exception;
+
+// import org.springframework.http.HttpStatus;
+// import org.springframework.http.ResponseEntity;
+// import org.springframework.web.bind.annotation.ControllerAdvice;
+// import org.springframework.web.bind.annotation.ExceptionHandler;
+// import org.springframework.web.context.request.WebRequest;
+
+// import java.util.Date;
+
+// /**
+//  * The type Global exception handler.
+//  *
+//  * @author Givantha Kalansuriya
+//  */
+// @ControllerAdvice
+// public class GlobalExceptionHandler {
+
+//   /**
+//    * Resource not found exception response entity.
+//    *
+//    * @param ex the ex
+//    * @param request the request
+//    * @return the response entity
+//    */
+//   @ExceptionHandler(ResourceNotFoundException.class)
+//   public ResponseEntity<?> resourceNotFoundException(
+//       ResourceNotFoundException ex, WebRequest request) {
+//     ErrorResponse errorDetails =
+//         new ErrorResponse(new Date(), HttpStatus.NOT_FOUND.toString(), ex.getMessage(), request.getDescription(false));
+//     return new ResponseEntity<>(errorDetails, HttpStatus.NOT_FOUND);
+//   }
+
+//   /**
+//    * Globle excpetion handler response entity.
+//    *
+//    * @param ex the ex
+//    * @param request the request
+//    * @return the response entity
+//    */
+//   @ExceptionHandler(Exception.class)
+//   public ResponseEntity<?> globleExcpetionHandler(Exception ex, WebRequest request) {
+//     ErrorResponse errorDetails =
+//         new ErrorResponse(new Date(), HttpStatus.INTERNAL_SERVER_ERROR.toString() ,ex.getMessage(), request.getDescription(false));
+//     return new ResponseEntity<>(errorDetails, HttpStatus.INTERNAL_SERVER_ERROR);
+//   }
+// }
 
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
-import org.springframework.web.bind.annotation.ControllerAdvice;
 import org.springframework.web.bind.annotation.ExceptionHandler;
-import org.springframework.web.context.request.WebRequest;
-
-import java.util.Date;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
 
-/**
- * The type Global exception handler.
- *
- * @author Givantha Kalansuriya
- */
-@ControllerAdvice
-public class GlobalExceptionHandler {
+@RestControllerAdvice
+public class GlobalExceptionHandler{
+    @ExceptionHandler(ResourceNotFoundException.class)
+    public ResponseEntity<ErrorResponse> handleResourceNotFoundException(ResourceNotFoundException ex) {
+        ErrorResponse errorResponse = new ErrorResponse(ex.getMessage(), HttpStatus.NOT_FOUND.value());
+        return ResponseEntity.status(HttpStatus.NOT_FOUND).body(errorResponse);
+    }
 
-  /**
-   * Resource not found exception response entity.
-   *
-   * @param ex the ex
-   * @param request the request
-   * @return the response entity
-   */
-  @ExceptionHandler(ResourceNotFoundException.class)
-  public ResponseEntity<?> resourceNotFoundException(
-      ResourceNotFoundException ex, WebRequest request) {
-    ErrorResponse errorDetails =
-        new ErrorResponse(new Date(), HttpStatus.NOT_FOUND.toString(), ex.getMessage(), request.getDescription(false));
-    return new ResponseEntity<>(errorDetails, HttpStatus.NOT_FOUND);
-  }
+    @ExceptionHandler(UserAlreadyExistException.class)
+    public ResponseEntity<ErrorResponse> handleAlreadyExistUserException(UserAlreadyExistException ex){
+        ErrorResponse errorResponse = new ErrorResponse(ex.getMessage(), HttpStatus.CONFLICT.value());
+        return ResponseEntity.status(HttpStatus.CONFLICT).body(errorResponse);
+    }
 
-  /**
-   * Globle excpetion handler response entity.
-   *
-   * @param ex the ex
-   * @param request the request
-   * @return the response entity
-   */
-  @ExceptionHandler(Exception.class)
-  public ResponseEntity<?> globleExcpetionHandler(Exception ex, WebRequest request) {
-    ErrorResponse errorDetails =
-        new ErrorResponse(new Date(), HttpStatus.INTERNAL_SERVER_ERROR.toString() ,ex.getMessage(), request.getDescription(false));
-    return new ResponseEntity<>(errorDetails, HttpStatus.INTERNAL_SERVER_ERROR);
-  }
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<ErrorResponse> handeleGlobalException(Exception ex){
+        ErrorResponse errorResponse = new ErrorResponse("INTERNAL_SERVER_ERROR", HttpStatus.INTERNAL_SERVER_ERROR.value());
+        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(errorResponse);
+    }
 }
diff --git a/src/main/java/com/staxrt/tutorial/exception/ResourceNotFoundException.java b/src/main/java/com/staxrt/tutorial/exception/ResourceNotFoundException.java
index 4cd4a8f..a014e81 100644
--- a/src/main/java/com/staxrt/tutorial/exception/ResourceNotFoundException.java
+++ b/src/main/java/com/staxrt/tutorial/exception/ResourceNotFoundException.java
@@ -1,42 +1,51 @@
-/*
- *
- *  Copyright (c) 2018-2020 Givantha Kalansuriya, This source is a part of
- *   Staxrt - sample application source code.
- *   http://staxrt.com
- *
- *   Licensed under the Apache License, Version 2.0 (the "License");
- *   you may not use this file except in compliance with the License.
- *   You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- *   Unless required by applicable law or agreed to in writing, software
- *   distributed under the License is distributed on an "AS IS" BASIS,
- *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *   See the License for the specific language governing permissions and
- *   limitations under the License.
- *
- */
+// /*
+//  *
+//  *  Copyright (c) 2018-2020 Givantha Kalansuriya, This source is a part of
+//  *   Staxrt - sample application source code.
+//  *   http://staxrt.com
+//  *
+//  *   Licensed under the Apache License, Version 2.0 (the "License");
+//  *   you may not use this file except in compliance with the License.
+//  *   You may obtain a copy of the License at
+//  *
+//  *      http://www.apache.org/licenses/LICENSE-2.0
+//  *
+//  *   Unless required by applicable law or agreed to in writing, software
+//  *   distributed under the License is distributed on an "AS IS" BASIS,
+//  *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  *   See the License for the specific language governing permissions and
+//  *   limitations under the License.
+//  *
+//  */
 
-package com.staxrt.tutorial.exception;
+ package com.staxrt.tutorial.exception;
 
-import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.ResponseStatus;
 
-/**
- * The type Resource not found exception.
- *
- * @author Givantha Kalansuriya
- */
-@ResponseStatus(value = HttpStatus.NOT_FOUND)
-public class ResourceNotFoundException extends Exception {
+ import org.springframework.http.HttpStatus;
+// import org.springframework.web.bind.annotation.ResponseStatus;
 
-  /**
-   * Instantiates a new Resource not found exception.
-   *
-   * @param message the message
-   */
-  public ResourceNotFoundException(String message) {
-    super(message);
+// /**
+//  * The type Resource not found exception.
+//  *
+//  * @author Givantha Kalansuriya
+//  */
+// @ResponseStatus(value = HttpStatus.NOT_FOUND)
+// public class ResourceNotFoundException extends Exception {
+
+//   /**
+//    * Instantiates a new Resource not found exception.
+//    *
+//    * @param message the message
+//    */
+//   public ResourceNotFoundException(String message) {
+//     super(message);
+//   }
+// }
+
+@ResponseStatus(org.springframework.http.HttpStatus.NOT_FOUND)
+public class ResourceNotFoundException extends RuntimeException {
+  public ResourceNotFoundException(String msg) {
+    super(msg);
   }
 }
diff --git a/src/main/java/com/staxrt/tutorial/exception/UserAlreadyExistException.java b/src/main/java/com/staxrt/tutorial/exception/UserAlreadyExistException.java
new file mode 100644
index 0000000..9777d8a
--- /dev/null
+++ b/src/main/java/com/staxrt/tutorial/exception/UserAlreadyExistException.java
@@ -0,0 +1,9 @@
+package com.staxrt.tutorial.exception;
+
+public class UserAlreadyExistException extends RuntimeException{
+
+    public UserAlreadyExistException(String msg) {
+        super(msg);
+    }
+
+}
diff --git a/src/main/java/com/staxrt/tutorial/model/User.java b/src/main/java/com/staxrt/tutorial/model/User.java
index c5d8e82..f73f734 100644
--- a/src/main/java/com/staxrt/tutorial/model/User.java
+++ b/src/main/java/com/staxrt/tutorial/model/User.java
@@ -43,7 +43,7 @@
 public class User {
 
     @Id
-    @GeneratedValue(strategy = GenerationType.AUTO)
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
     private long id;
 
     @Column(name = "first_name", nullable = false)
diff --git a/src/main/java/com/staxrt/tutorial/repository/UserRepository.java b/src/main/java/com/staxrt/tutorial/repository/UserRepository.java
index a79fddb..1c5e0f5 100644
--- a/src/main/java/com/staxrt/tutorial/repository/UserRepository.java
+++ b/src/main/java/com/staxrt/tutorial/repository/UserRepository.java
@@ -10,4 +10,6 @@
  * @author Givantha Kalansuriya
  */
 @Repository
-public interface UserRepository extends JpaRepository<User, Long> {}
+public interface UserRepository extends JpaRepository<User, Long> {
+
+    boolean existsByEmail(String email);}
diff --git a/src/main/java/com/staxrt/tutorial/service/UserService.java b/src/main/java/com/staxrt/tutorial/service/UserService.java
new file mode 100644
index 0000000..cd57665
--- /dev/null
+++ b/src/main/java/com/staxrt/tutorial/service/UserService.java
@@ -0,0 +1,123 @@
+package com.staxrt.tutorial.service;
+
+import java.util.Date;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.stereotype.Service;
+
+import com.staxrt.tutorial.dto.PageResponseDto;
+import com.staxrt.tutorial.dto.UserDto;
+import com.staxrt.tutorial.dto.UserResponseDto;
+import com.staxrt.tutorial.exception.ResourceNotFoundException;
+import com.staxrt.tutorial.exception.UserAlreadyExistException;
+import com.staxrt.tutorial.model.User;
+import com.staxrt.tutorial.repository.UserRepository;
+
+@Service
+public class UserService {
+    @Autowired
+    UserRepository userRepository;
+
+    // get all users
+
+    public List<User> findAllUserse() {
+        return userRepository.findAll();
+    }
+
+    // find user by Id
+    public User findByUserId(Long id) {
+        return userRepository.findById(id)
+                .orElseThrow(() -> new ResourceNotFoundException("user with id " + id + " not found"));
+    }
+
+    // create user
+
+    public UserResponseDto createUser(UserDto userDto) {
+        if (userRepository.existsByEmail(userDto.getEmail())) {
+            throw new UserAlreadyExistException("User already exist by email: " + userDto.getEmail());
+        }
+        User user = new User();
+        user.setFirstName(userDto.getFirstName());
+        user.setLastName(userDto.getLastName());    
+        user.setEmail(userDto.getEmail());
+        user.setCreatedAt(new Date());
+        user.setUpdatedAt(new Date());
+        user.setCreatedBy("System");
+        user.setUpdatedBy("System");
+
+        User savedUser = userRepository.save(user);
+
+    UserResponseDto responseDto = new UserResponseDto();
+        responseDto.setId(savedUser.getId());
+        responseDto.setFirstname(savedUser.getFirstName());
+        responseDto.setLastName(savedUser.getLastName());
+        responseDto.setEmail(savedUser.getEmail());
+        return responseDto;
+
+
+    }
+
+    // update User
+    public UserResponseDto updateuser(Long userId, UserDto userDetails) {
+        User user = userRepository
+                .findById(userId)
+                .orElseThrow(() -> new ResourceNotFoundException("User not found on :: " + userId));
+
+        user.setEmail(userDetails.getEmail());
+        user.setLastName(userDetails.getLastName());
+        user.setFirstName(userDetails.getFirstName());
+        user.setUpdatedAt(new Date());
+        final User updatedUser = userRepository.save(user);
+
+        UserResponseDto userResponseDto = new UserResponseDto();
+        userResponseDto.setId(updatedUser.getId());
+        userResponseDto.setEmail(updatedUser.getEmail());
+        userResponseDto.setFirstname(updatedUser.getFirstName());
+        userResponseDto.setLastName(updatedUser.getLastName());
+        return userResponseDto;
+    }
+
+    //delete user
+
+     public Map<String, Boolean> deleteUser(Long userId) {
+        User user = userRepository
+                .findById(userId)
+                .orElseThrow(() -> new ResourceNotFoundException("User not found on :: " + userId));
+
+        userRepository.delete(user);
+        Map<String, Boolean> response = new HashMap<>();
+        response.put("deleted", Boolean.TRUE);
+        return response;
+    }
+
+    // pagination
+
+    public PageResponseDto<UserResponseDto> getUsers(int page, int size, String sortBy, String direction) {
+        org.springframework.data.domain.Sort sort = direction.equalsIgnoreCase("desc")
+                ? Sort.by(sortBy).descending()
+                : Sort.by(sortBy).ascending();
+
+        Pageable pageable = PageRequest.of(page, size, sort);
+        Page<User> userpage = userRepository.findAll(pageable);
+
+        List<UserResponseDto> users = userpage.getContent()
+                .stream()
+                .map(user -> new UserResponseDto(
+                        user.getId(), user.getFirstName(), user.getLastName(), user.getEmail()))
+                .toList();
+
+        return new PageResponseDto<>(users, userpage.getNumber(), userpage.getSize(), userpage.getTotalElements(),
+                userpage.getTotalPages(), userpage.isFirst(), userpage.isLast());
+
+    }
+
+   
+
+}
diff --git a/src/main/resources/application.properties b/src/main/resources/application.properties
index affb74d..791fd39 100644
--- a/src/main/resources/application.properties
+++ b/src/main/resources/application.properties
@@ -1,8 +1,7 @@
 ## Database Properties
-spring.datasource.url = jdbc:mysql://localhost:3306/users_database?useSSL=false
-spring.datasource.username = root
-spring.datasource.password = root
-
+spring.datasource.url = jdbc:mysql://localhost:3306/demo_db
+spring.datasource.username=root
+spring.datasource.password=1234
 
 ## Hibernate Properties
 # The SQL dialect makes Hibernate generate better SQL for the chosen database