From 32f836b5bee6018b38454428c9fba8842bbe4f46 Mon Sep 17 00:00:00 2001
From: Dmytro Varukha <132067460+DmytroV95@users.noreply.github.com>
Date: Tue, 3 Oct 2023 11:56:21 +0300
Subject: [PATCH] [GLOBAL EXCEPTION HANDLER] Created global exception handler

* created car controller

* fixed checkstyle

* added global exception handler

* deleted empty line in CarController
---
 .../controller/CarController.java             |  1 -
 .../CustomGlobalExceptionHandler.java         | 79 +++++++++++++++++++
 .../exception/EntityNotFoundException.java    |  7 ++
 .../exception/ErrorResponseDto.java           |  9 +++
 .../exception/RegistrationException.java      |  7 ++
 5 files changed, 102 insertions(+), 1 deletion(-)
 create mode 100644 src/main/java/com/project/carsharingapp/exception/CustomGlobalExceptionHandler.java
 create mode 100644 src/main/java/com/project/carsharingapp/exception/EntityNotFoundException.java
 create mode 100644 src/main/java/com/project/carsharingapp/exception/ErrorResponseDto.java
 create mode 100644 src/main/java/com/project/carsharingapp/exception/RegistrationException.java

diff --git a/src/main/java/com/project/carsharingapp/controller/CarController.java b/src/main/java/com/project/carsharingapp/controller/CarController.java
index 9f3a307..fcbe3f1 100644
--- a/src/main/java/com/project/carsharingapp/controller/CarController.java
+++ b/src/main/java/com/project/carsharingapp/controller/CarController.java
@@ -24,7 +24,6 @@
 @RestController
 @RequestMapping(value = "/cars")
 public class CarController {
-
     @PostMapping
     @ResponseStatus(HttpStatus.CREATED)
     @Operation(summary = "Save new car",
diff --git a/src/main/java/com/project/carsharingapp/exception/CustomGlobalExceptionHandler.java b/src/main/java/com/project/carsharingapp/exception/CustomGlobalExceptionHandler.java
new file mode 100644
index 0000000..9947cce
--- /dev/null
+++ b/src/main/java/com/project/carsharingapp/exception/CustomGlobalExceptionHandler.java
@@ -0,0 +1,79 @@
+package com.project.carsharingapp.exception;
+
+import java.time.LocalDateTime;
+import java.util.List;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.HttpStatusCode;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.validation.ObjectError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.context.request.WebRequest;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+@ControllerAdvice
+public class CustomGlobalExceptionHandler extends ResponseEntityExceptionHandler {
+    @Override
+    protected ResponseEntity<Object> handleMethodArgumentNotValid(
+            MethodArgumentNotValidException ex,
+            HttpHeaders headers,
+            HttpStatusCode status,
+            WebRequest request
+    ) {
+        List<String> errors = ex.getBindingResult().getAllErrors()
+                .stream()
+                .map(this::getErrorMessage)
+                .toList();
+        ErrorResponseDto response = new ErrorResponseDto(
+                LocalDateTime.now(),
+                HttpStatus.BAD_REQUEST,
+                errors.toArray(new String[0])
+        );
+        return new ResponseEntity<>(response, headers, HttpStatus.BAD_REQUEST);
+    }
+
+    @ExceptionHandler(RegistrationException.class)
+    protected ResponseEntity<Object> handleRegistrationException(
+            RegistrationException exception) {
+        ErrorResponseDto response = new ErrorResponseDto(
+                LocalDateTime.now(),
+                HttpStatus.BAD_REQUEST,
+                new String[]{exception.getMessage()}
+        );
+        return new ResponseEntity<>(response, HttpStatus.BAD_REQUEST);
+    }
+
+    @ExceptionHandler(RuntimeException.class)
+    protected ResponseEntity<Object> handleAllErrors(
+            RuntimeException exception) {
+        ErrorResponseDto response = new ErrorResponseDto(
+                LocalDateTime.now(),
+                HttpStatus.INTERNAL_SERVER_ERROR,
+                new String[]{exception.getMessage()}
+        );
+        return new ResponseEntity<>(response, HttpStatus.INTERNAL_SERVER_ERROR);
+    }
+
+    @ExceptionHandler(EntityNotFoundException.class)
+    protected ResponseEntity<Object> handleAllErrors(
+            EntityNotFoundException exception) {
+        ErrorResponseDto response = new ErrorResponseDto(
+                LocalDateTime.now(),
+                HttpStatus.NOT_FOUND,
+                new String[]{exception.getMessage()}
+        );
+        return new ResponseEntity<>(response, HttpStatus.NOT_FOUND);
+    }
+
+    private String getErrorMessage(ObjectError e) {
+        if (e instanceof FieldError) {
+            String field = ((FieldError) e).getField();
+            String message = e.getDefaultMessage();
+            return field + " " + message;
+        }
+        return e.getDefaultMessage();
+    }
+}
diff --git a/src/main/java/com/project/carsharingapp/exception/EntityNotFoundException.java b/src/main/java/com/project/carsharingapp/exception/EntityNotFoundException.java
new file mode 100644
index 0000000..a16ebd2
--- /dev/null
+++ b/src/main/java/com/project/carsharingapp/exception/EntityNotFoundException.java
@@ -0,0 +1,7 @@
+package com.project.carsharingapp.exception;
+
+public class EntityNotFoundException extends RuntimeException {
+    public EntityNotFoundException(String message) {
+        super(message);
+    }
+}
diff --git a/src/main/java/com/project/carsharingapp/exception/ErrorResponseDto.java b/src/main/java/com/project/carsharingapp/exception/ErrorResponseDto.java
new file mode 100644
index 0000000..2ca9480
--- /dev/null
+++ b/src/main/java/com/project/carsharingapp/exception/ErrorResponseDto.java
@@ -0,0 +1,9 @@
+package com.project.carsharingapp.exception;
+
+import java.time.LocalDateTime;
+import org.springframework.http.HttpStatus;
+
+public record ErrorResponseDto(LocalDateTime timestamp,
+                               HttpStatus status,
+                               String[] errors){
+}
diff --git a/src/main/java/com/project/carsharingapp/exception/RegistrationException.java b/src/main/java/com/project/carsharingapp/exception/RegistrationException.java
new file mode 100644
index 0000000..a8a210b
--- /dev/null
+++ b/src/main/java/com/project/carsharingapp/exception/RegistrationException.java
@@ -0,0 +1,7 @@
+package com.project.carsharingapp.exception;
+
+public class RegistrationException extends RuntimeException {
+    public RegistrationException(String message) {
+        super(message);
+    }
+}