feat: Implement Global Exception Handling with @RestControllerAdvice

src/main/java/com/app/dto/StandardResponse.java

@@ -0,0 +1,15 @@
+package com.app.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class StandardResponse<T> {
+    private String responseCode;          // The response code (e.g., "E1005")
+    private String responseDescription;   // The response description (e.g., "Invalid method argument.")
+    private T response;                   // Generic type to hold any object (e.g., data or error details)
+    private boolean isOkay;               // Indicates success (true) or failure (false)
+}

src/main/java/com/app/exception/CustomRuntimeException.java

@@ -0,0 +1,26 @@
+package com.app.exception;
+
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+public class CustomRuntimeException extends RuntimeException {
+
+    private final String responseCode;       // Unique error code
+    private final HttpStatus httpStatus;    // HTTP status associated with the exception
+    private final Object[] args;
+
+    /**
+     * Constructor for CustomRuntimeException.
+     *
+     * @param responseCode The unique error code.
+     * @param httpStatus   The HTTP status associated with the exception.
+     * @param args         Arguments for dynamic message formatting.
+     */
+    public CustomRuntimeException(String responseCode, HttpStatus httpStatus, Object... args) {
+        super(responseCode); // Use responseCode as the default message for the exception
+        this.responseCode = responseCode;
+        this.httpStatus = httpStatus;
+        this.args = args;
+    }
+}

src/main/java/com/app/exception/RestExceptionHandler.java

@@ -0,0 +1,73 @@
+package com.app.exception;
+
+import com.app.dto.StandardResponse;
+import com.app.utils.MessageConstant;
+import com.app.utils.ResponseUtil;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+import java.util.stream.Collectors;
+
+@RestControllerAdvice
+@RequiredArgsConstructor
+@Log4j2
+public class RestExceptionHandler {
+
+    private final ResponseUtil responseUtil;
+
+    /**
+     * Handles validation errors for method arguments.
+     *
+     * @param ex The MethodArgumentNotValidException to handle.
+     * @return A ResponseEntity with a structured error response.
+     */
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<StandardResponse<Object>> handleMethodArgumentNotValidException(MethodArgumentNotValidException ex) {
+        return buildErrorResponse(MessageConstant.E1005, HttpStatus.BAD_REQUEST, ex.getBindingResult().getFieldErrors().stream()
+                .collect(Collectors.toMap(FieldError::getField, responseUtil::getMessage)));
+    }
+
+    /**
+     * Handles custom ServiceException.
+     *
+     * @param ex The ServiceException to handle.
+     * @return A ResponseEntity with an error response.
+     */
+    @ExceptionHandler(CustomRuntimeException.class)
+    public ResponseEntity<StandardResponse<Object>> handleServiceException(CustomRuntimeException ex) {
+        log.error("Service exception: ", ex);
+        return buildErrorResponse(ex.getResponseCode(), ex.getHttpStatus(), ex.getArgs());
+    }
+
+    /**
+     * Handles generic RuntimeExceptions.
+     *
+     * @param ex The RuntimeException to handle.
+     * @return A ResponseEntity with an error response.
+     */
+    @ExceptionHandler(RuntimeException.class)
+    public ResponseEntity<StandardResponse<Object>> handleRuntimeException(RuntimeException ex) {
+        log.error("Runtime exception: ", ex);
+        return buildErrorResponse(MessageConstant.E1000, HttpStatus.INTERNAL_SERVER_ERROR, ex.getMessage());
+    }
+
+
+    /**
+     * Utility method to build a standardized error response.
+     *
+     * @param responseCode The response code for the error.
+     * @param details      The error details to include in the response.
+     * @param httpStatus   The HTTP status for the response.
+     * @return A ResponseEntity containing the StandardResponse.
+     */
+    private ResponseEntity<StandardResponse<Object>> buildErrorResponse(String responseCode, HttpStatus httpStatus, Object... details) {
+        StandardResponse<Object> response = responseUtil.createErrorResponse(responseCode, details);
+        return ResponseEntity.status(httpStatus).body(response);
+    }
+}

src/main/java/com/app/utils/MessageConstant.java

@@ -0,0 +1,19 @@
+package com.app.utils;
+
+public class MessageConstant {
+    private MessageConstant() {
+    }
+    //Success
+    public static final String S0001 = "s0001";
+    // Error Message Constant
+    public static final String E1000 = "e1000";
+    public static final String E1001 = "e1001";
+    public static final String E1002 = "e1002";
+    public static final String E1003 = "e1003";
+    public static final String E1004 = "e1004";
+    public static final String E1005 = "e1005";
+    public static final String E1006 = "e1006";
+    public static final String E1007 = "e1007";
+
+
+}

src/main/java/com/app/utils/ResponseUtil.java

@@ -0,0 +1,59 @@
+package com.app.utils;
+
+import com.app.dto.StandardResponse;
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.MessageSource;
+import org.springframework.context.MessageSourceResolvable;
+import org.springframework.context.i18n.LocaleContextHolder;
+import org.springframework.stereotype.Component;
+import org.springframework.util.StringUtils;
+
+@Component
+@RequiredArgsConstructor
+public class ResponseUtil {
+
+    private final MessageSource messageSource;
+
+
+    /**
+     * Creates a success response.
+     *
+     * @param responseCode   The response code for success.
+     * @param responseObject The object to include in the response.
+     * @return A StandardResponse object.
+     */
+    public <T> StandardResponse<T> createSuccessResponse(String responseCode, T responseObject, Object... args) {
+        return new StandardResponse<>(StringUtils.uncapitalizeAsProperty(responseCode), getMessage("success.description." + responseCode, args), responseObject, true);
+    }
+
+    /**
+     * Creates an error response.
+     *
+     * @param responseCode The response code for the error.
+     * @param errorDetails Optional error details to include in the response.
+     * @return A StandardResponse object.
+     */
+    public <T> StandardResponse<T> createErrorResponse(String responseCode, T errorDetails, Object... args) {
+        return new StandardResponse<>(StringUtils.uncapitalizeAsProperty(responseCode), getMessage("error.description." + responseCode, args), errorDetails, false);
+    }
+
+    /**
+     * Retrieves a message from the MessageSource based on the current locale.
+     *
+     * @param key The message key.
+     * @return The localized message.
+     */
+    public String getMessage(String key, Object... args) {
+        return messageSource.getMessage(key, args, LocaleContextHolder.getLocale());
+    }
+
+    /**
+     * Retrieves a message from the MessageSource based on the current locale.
+     *
+     * @return The localized message.
+     */
+    public String getMessage(MessageSourceResolvable resolvable) {
+        return messageSource.getMessage(resolvable, LocaleContextHolder.getLocale());
+    }
+
+}

src/main/resources/application-local.yml

@@ -2,3 +2,11 @@ app:
   logs:
     path: C:/${spring.application.name}/logs
 
+####################### START READ PROPERTIES FILE #######################
+spring:
+  messages:
+    basename: error_messages,success_messages  # Or provide full paths if needed
+    cache-duration: 3600
+    encoding: UTF-8
+  web:
+    locale: en

src/main/resources/error_messages.properties

@@ -0,0 +1,42 @@
+# Error Code Properties
+error.code.e1000=E1000
+error.description.e1000=Something went wrong! {0}
+
+error.code.e1001=E1001
+error.description.e1001=Authorization header cannot be blank or invalid.
+
+error.code.e1002=E1002
+error.description.e1002=Unable to extract email ID from the token. Please generate a new token.
+
+error.code.e1003=E1003
+error.description.e1003=Invalid token. Please generate a new token.
+
+error.code.e1004=E1004
+error.description.e1004=Authentication token is required.
+
+error.code.e1005=E1005
+error.description.e1005=Invalid method argument.
+
+error.code.e1006=E1006
+error.description.e1006=No matching enum found.
+
+error.code.e1007=E1007
+error.description.e1007=Duplicate entry detected.
+
+
+
+# fullName validations
+fullName.not.blank=Full name cannot be blank
+fullName.size=Full name must not exceed 100 characters
+# email validations
+email.not.blank=Email cannot be blank
+email.invalid=Please provide a valid email address
+# password validations
+password.not.blank=Password cannot be blank
+password.pattern=Password must be at least 8 characters, include an alphanumeric character, and one special character
+# authProvider validations
+authProvider.notnull=Auth provider is required
+authProvider.invalid=Auth provider must be one of the values: 4, 5, 6
+# roleId validations
+roleId.notnull=Role ID is required
+roleId.invalid=Role ID must be either 2 or 3

src/main/resources/error_messages_hi.properties

@@ -0,0 +1,15 @@
+# fullName validations
+fullName.no.tblank=???? ??? ???? ???? ?? ????
+fullName.size=???? ??? 100 ??????? ?? ???? ???? ???? ?????
+# email validations
+email.not.blank=???? ???? ???? ?? ????
+email.invalid=????? ?? ????? ???? ??? ?????? ????
+# password validations
+password.not.blank=??????? ???? ???? ?? ????
+password.pattern=??????? ?? ?? ?? 8 ??????? ?? ???? ?????, ?? ??????????????? ?? ?? ????? ????? ????? ???? ?????
+# authProvider validations
+authProvider.notnull=?? ????????? ?????? ??
+authProvider.invalid=?? ????????? ?? ??? 3, 4, 5 ??? ?? ?? ???? ?????
+# roleId validations
+roleId.notnull=?????? ???? ?????? ??
+roleId.invalid=?????? ???? 2 ?? 3 ??? ?? ?? ???? ?????

src/main/resources/success_messages.properties

@@ -0,0 +1,2 @@
+success.description.s0001=Request processed successfully.
+success.description.s0002=Token generated successfully.

src/main/resources/success_messages_hi.properties

@@ -0,0 +1,15 @@
+# fullName validations
+fullName.no.tblank=???? ??? ???? ???? ?? ????
+fullName.size=???? ??? 100 ??????? ?? ???? ???? ???? ?????
+# email validations
+email.not.blank=???? ???? ???? ?? ????
+email.invalid=????? ?? ????? ???? ??? ?????? ????
+# password validations
+password.not.blank=??????? ???? ???? ?? ????
+password.pattern=??????? ?? ?? ?? 8 ??????? ?? ???? ?????, ?? ??????????????? ?? ?? ????? ????? ????? ???? ?????
+# authProvider validations
+authProvider.notnull=?? ????????? ?????? ??
+authProvider.invalid=?? ????????? ?? ??? 3, 4, 5 ??? ?? ?? ???? ?????
+# roleId validations
+roleId.notnull=?????? ???? ?????? ??
+roleId.invalid=?????? ???? 2 ?? 3 ??? ?? ?? ???? ?????