Sprint-15 [Yurii Leskiv] Implemented error handling

README.md

@@ -1,3 +1,4 @@
+[![Review Assignment Due Date](https://classroom.github.com/assets/deadline-readme-button-22041afd0340ce965d47ae6ef1cefeee28c7c493a6346c4f15d667ab976d596c.svg)](https://classroom.github.com/a/fcC7yEpn)
 # Java Online Marathon
 ## To-Do List Project
 1. Implement exception handling for custom exception.

src/main/java/com/softserve/itacademy/exception/GlobalExceptionHandler.java

@@ -0,0 +1,38 @@
+package com.softserve.itacademy.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.servlet.ModelAndView;
+
+import javax.persistence.EntityNotFoundException;
+import javax.servlet.http.HttpServletRequest;
+import java.time.LocalDateTime;
+
+@ControllerAdvice
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(Exception.class)
+    public ModelAndView handleServerException (Exception  e, HttpServletRequest request) {
+        ModelAndView mav = new ModelAndView();
+        mav.setViewName("500-page");
+        mav.setStatus(HttpStatus.INTERNAL_SERVER_ERROR);
+        mav.addObject("message", "Message: " + e.getMessage());
+        mav.addObject("timestamp", "Date: " +LocalDateTime.now());
+        mav.addObject("path", "Path: " + request.getRequestURI());
+        return mav;
+    }
+
+    @ExceptionHandler({EntityNotFoundException.class, NullEntityReferenceException.class})
+    public ModelAndView handleEntityNotFoundException(RuntimeException e, HttpServletRequest request) {
+        ModelAndView mav = new ModelAndView();
+        mav.setViewName("404-page");
+        mav.setStatus(e instanceof EntityNotFoundException ? HttpStatus.NOT_FOUND : HttpStatus.BAD_REQUEST);
+        mav.addObject("message", "Message: " + e.getMessage());
+        mav.addObject("error", "Error: " + (e instanceof EntityNotFoundException ? "Not Found" :"Bad Request"));
+        mav.addObject("timestamp", "Date: " +LocalDateTime.now());
+        mav.addObject("path", "Path: " + request.getRequestURI());
+        return mav;
+    }
+
+}

src/main/java/com/softserve/itacademy/exception/NullEntityReferenceException.java

@@ -0,0 +1,12 @@
+package com.softserve.itacademy.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ResponseStatus(HttpStatus.BAD_REQUEST)
+public class NullEntityReferenceException extends RuntimeException {
+
+    public NullEntityReferenceException(String message) {
+        super(message);
+    }
+}

src/main/java/com/softserve/itacademy/repository/RoleRepository.java

@@ -6,4 +6,7 @@
 
 @Repository
 public interface RoleRepository extends JpaRepository<Role, Long> {
+
+    Role removeById(long id);
+
 }

src/main/java/com/softserve/itacademy/repository/StateRepository.java

@@ -15,4 +15,6 @@ public interface StateRepository extends JpaRepository<State, Long> {
 
     @Query(value = "select * from states order by id", nativeQuery = true)
     List<State> getAll();
+
+    State removeById(long id);
 }

src/main/java/com/softserve/itacademy/service/impl/RoleServiceImpl.java

@@ -1,10 +1,12 @@
 package com.softserve.itacademy.service.impl;
 
+import com.softserve.itacademy.exception.NullEntityReferenceException;
 import com.softserve.itacademy.model.Role;
 import com.softserve.itacademy.repository.RoleRepository;
 import com.softserve.itacademy.service.RoleService;
 import org.springframework.stereotype.Service;
 
+import javax.persistence.EntityNotFoundException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
@@ -20,25 +22,35 @@ public RoleServiceImpl(RoleRepository roleRepository) {
 
     @Override
     public Role create(Role role) {
-            return roleRepository.save(role);
+        return Optional
+                .ofNullable(role)
+                .map(roleRepository::save)
+                .orElseThrow(() -> new NullEntityReferenceException("Role can't be null and won't be affected!"));
     }
 
     @Override
     public Role readById(long id) {
-        Optional<Role> optional = roleRepository.findById(id);
-            return optional.get();
+        return Optional
+                .of(id)
+                .flatMap(roleRepository::findById)
+                .orElseThrow(() -> new EntityNotFoundException("Role with id " + id + " not found"));
     }
 
     @Override
     public Role update(Role role) {
-            Role oldRole = readById(role.getId());
-                return roleRepository.save(role);
+        return Optional
+                .ofNullable(role)
+                .map(roleRepository::save)
+                .orElseThrow(() -> new NullEntityReferenceException("Role can't be null and won't be updated"));
     }
 
     @Override
     public void delete(long id) {
-        Role role = readById(id);
-            roleRepository.delete(role);
+        Optional
+                .of(id)
+                .filter(roleRepository::existsById)
+                .map(roleRepository::removeById)
+                .orElseThrow(() -> new EntityNotFoundException("Role with id " + id + " not found"));
     }
 
     @Override

src/main/java/com/softserve/itacademy/service/impl/StateServiceImpl.java

@@ -1,10 +1,12 @@
 package com.softserve.itacademy.service.impl;
 
+import com.softserve.itacademy.exception.NullEntityReferenceException;
 import com.softserve.itacademy.model.State;
 import com.softserve.itacademy.repository.StateRepository;
 import com.softserve.itacademy.service.StateService;
 import org.springframework.stereotype.Service;
 
+import javax.persistence.EntityNotFoundException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
@@ -19,25 +21,35 @@ public StateServiceImpl(StateRepository stateRepository) {
 
     @Override
     public State create(State state) {
-            return stateRepository.save(state);
+        return Optional
+                .ofNullable(state)
+                .map(stateRepository::save)
+                .orElseThrow(() -> new NullEntityReferenceException("State can't be null and won't be affected!"));
     }
 
     @Override
     public State readById(long id) {
-        Optional<State> optional = stateRepository.findById(id);
-            return optional.get();
+        return Optional
+                .of(id)
+                .flatMap(stateRepository::findById)
+                .orElseThrow(() -> new EntityNotFoundException("State with id " + id + " not found"));
     }
 
     @Override
     public State update(State state) {
-            State oldState = readById(state.getId());
-                return stateRepository.save(state);
+        return Optional
+                .ofNullable(state)
+                .map(stateRepository::save)
+                .orElseThrow(() -> new NullEntityReferenceException("State can't be null and won't be updated"));
     }
 
     @Override
     public void delete(long id) {
-        State state = readById(id);
-            stateRepository.delete(state);
+        Optional
+                .of(id)
+                .filter(stateRepository::existsById)
+                .map(stateRepository::removeById)
+                .orElseThrow(() -> new EntityNotFoundException("State with id " + id + " not found"));
     }
 
     @Override

src/main/resources/templates/404-page.html

@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>404-Error</title>
+</head>
+<body>
+<h2 th:text="${error}"></h2>
+<h2 th:text="${message}"></h2>
+<h2 th:text="${timestamp}"></h2>
+<h2 th:text="'Status: ' + ${#response.getStatus()}"></h2>
+<h2 th:text="${path}"></h2>
+</body>
+</html>

src/main/resources/templates/500-page.html

@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Title</title>
+</head>
+<body>
+<h2>Error: Internal Server Error</h2>
+<h2>Status: 500</h2>
+<h2 th:text="${message}"></h2>
+<h2 th:text="${timestamp}"></h2>
+<h2 th:text="${path}"></h2>
+</body>
+</html>