refacto error handling

build.gradle

@@ -33,7 +33,8 @@ dependencies {
     annotationProcessor 'org.projectlombok:lombok'
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
     testImplementation 'org.springframework.restdocs:spring-restdocs-mockmvc'
-    // https://mvnrepository.com/artifact/com.google.code.gson/gson
+
+    // Added after spring init
     implementation 'com.google.code.gson:gson:2.8.9'
 
 }

src/main/java/com/example/apispringgradleb2boost/controller/PartnerController.java

@@ -1,20 +1,21 @@
 package com.example.apispringgradleb2boost.controller;
 
+import com.example.apispringgradleb2boost.exceptionhandling.CustomError;
 import com.example.apispringgradleb2boost.model.Partner;
 import com.example.apispringgradleb2boost.service.PartnerService;
-import com.google.gson.Gson;
-import lombok.SneakyThrows;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.RestController;
-import org.springframework.web.server.ResponseStatusException;
+
+import com.google.gson.Gson;
 
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
 import java.io.PrintWriter;
-import java.util.HashMap;
 import java.util.Optional;
 
 @RestController
@@ -23,7 +24,6 @@ public class PartnerController {
     @Autowired
     PartnerService partnerService;
 
-
     @GetMapping("/partners")
     public Iterable<Partner> getPartners() {
         return partnerService.getPartners();
@@ -38,17 +38,15 @@ public class PartnerController {
         } else {
             // Error handling when !partner.isPresent()
             response.setStatus(HttpStatus.NOT_FOUND.value());
-            response.setContentType("application/json");
+            response.setContentType(String.valueOf(MediaType.APPLICATION_JSON));
             response.setCharacterEncoding("UTF-8");
 
-            HashMap<String, String> responseBody = new HashMap<>();
-            responseBody.put("code", String.valueOf(HttpStatus.NOT_FOUND.value()));
-            responseBody.put("message", String.format("Partner with id %d not found!", Id));
-
             PrintWriter out = response.getWriter();
-            out.print(new Gson().toJson(responseBody));
+            out.print(new Gson().toJson(
+                    new CustomError(HttpStatus.NOT_FOUND.value(),
+                            String.format("Partner with id %d not found!", Id))
+            ));
             out.flush();
-
             return null;
         }
     }

src/main/java/com/example/apispringgradleb2boost/exceptionhandling/CustomError.java

@@ -0,0 +1,16 @@
+package com.example.apispringgradleb2boost.exceptionhandling;
+
+import lombok.Data;
+
+@Data
+public class CustomError {
+
+    private int code;
+    private String message;
+
+    public CustomError(int code, String message) {
+        this.code = code;
+        this.message = message;
+    }
+
+}

src/main/java/com/example/apispringgradleb2boost/exceptionhandling/GeneralExceptionHandler.java

@@ -0,0 +1,39 @@
+package com.example.apispringgradleb2boost.exceptionhandling;
+
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+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.NoHandlerFoundException;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler;
+
+@ControllerAdvice
+public class GeneralExceptionHandler extends ResponseEntityExceptionHandler {
+
+    @ExceptionHandler({Exception.class})
+    public ResponseEntity<Object> handleAll(Exception ex, WebRequest request) {
+        CustomError customError = new CustomError(HttpStatus.INTERNAL_SERVER_ERROR.value(), ex.getLocalizedMessage());
+        return new ResponseEntity<Object>(customError, new HttpHeaders(), customError.getCode());
+    }
+
+    @Override
+    protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex,
+                                                                  HttpHeaders headers,
+                                                                  HttpStatus status,
+                                                                  WebRequest request) {
+
+        CustomError customError = new CustomError(HttpStatus.BAD_REQUEST.value(), ex.getLocalizedMessage());
+        return handleExceptionInternal(ex, customError, headers, HttpStatus.valueOf(customError.getCode()), request);
+    }
+
+    @Override
+    protected ResponseEntity<Object> handleNoHandlerFoundException(
+            NoHandlerFoundException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
+
+        CustomError customError = new CustomError(HttpStatus.NOT_FOUND.value(), ex.getLocalizedMessage());
+        return new ResponseEntity<Object>(customError, new HttpHeaders(), customError.getCode());
+    }
+}

src/main/java/com/example/apispringgradleb2boost/exceptions/resolvers/ExceptionResolver.java

@@ -1,34 +0,0 @@
-package com.example.apispringgradleb2boost.exceptions.resolvers;
-
-import org.springframework.web.bind.annotation.ExceptionHandler;
-import org.springframework.web.bind.annotation.RestControllerAdvice;
-import org.springframework.web.bind.MissingPathVariableException;
-import org.springframework.web.servlet.NoHandlerFoundException;
-
-import javax.servlet.http.HttpServletRequest;
-import java.util.HashMap;
-
-@RestControllerAdvice
-public class ExceptionResolver {
-
-    @ExceptionHandler(Exception.class)
-    public HashMap<String, String> handleException(HttpServletRequest request, Exception e) {
-        HashMap<String, String> response = new HashMap<>();
-        response.put("message", e.getMessage());
-        return response;
-    }
-
-    @ExceptionHandler(MissingPathVariableException.class)
-    public HashMap<String, String> handleMissingPathVariableException(HttpServletRequest request, MissingPathVariableException e) {
-        HashMap<String, String> response = new HashMap<>();
-        response.put("message", "Required path variable is missing in this request. Please add it to your request.");
-        return response;
-    }
-
-    @ExceptionHandler(NoHandlerFoundException.class)
-    public HashMap<String, String> handleNotFoundResourceException(HttpServletRequest request, NoHandlerFoundException e) {
-        HashMap<String, String> response = new HashMap<>();
-        response.put("message", "Requested resource wasn't found on the server");
-        return response;
-    }
-}

src/main/java/com/example/apispringgradleb2boost/repository/PartnerRepository.java

@@ -2,6 +2,8 @@ package com.example.apispringgradleb2boost.repository;
 
 import com.example.apispringgradleb2boost.model.Partner;
 import org.springframework.data.repository.PagingAndSortingRepository;
+import org.springframework.stereotype.Repository;
 
+@Repository
 public interface PartnerRepository extends PagingAndSortingRepository<Partner, Long> {
 }