adding javadocs and updating service.js to match the backend

backend/src/main/java/com/assettrack/AssetTrackApplication.java

@@ -6,6 +6,9 @@
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.scheduling.annotation.EnableScheduling;
 
+/**
+ * Main Spring Boot application entry point for AssetTrack.
+ */
 @SpringBootApplication
 @EnableScheduling
 @EnableConfigurationProperties(RsaKeyProperties.class)

backend/src/main/java/com/assettrack/common/exception/GlobalExceptionHandler.java

@@ -21,118 +21,146 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
+import lombok.extern.slf4j.Slf4j;
 
+/**
+ * Global exception handler that converts backend exceptions into ApiError
+ * responses.
+ */
+@Slf4j
 @RestControllerAdvice
 public class GlobalExceptionHandler {
 
-    private ApiError buildApiError(HttpStatus status, String message, String path) {
-        return ApiError.builder()
-                .timestamp(Instant.now().toString())
-                .status(status.value())
-                .error(status.getReasonPhrase())
-                .message(message)
-                .path(path)
-                .build();
-    }
-
-    @ExceptionHandler(MethodArgumentNotValidException.class)
-    public ResponseEntity<ApiError> handleValidationExceptions(MethodArgumentNotValidException ex, HttpServletRequest request) {
-        List<FieldError> fieldErrors = ex.getBindingResult().getFieldErrors().stream()
-                .map(error -> FieldError.builder()
-                        .field(error.getField())
-                        .message(error.getDefaultMessage())
-                        .build())
-                .collect(Collectors.toList());
-
-        ApiError apiError = ApiError.builder()
-                .timestamp(Instant.now().toString())
-                .status(HttpStatus.BAD_REQUEST.value())
-                .error(HttpStatus.BAD_REQUEST.getReasonPhrase())
-                .message("Validation failed")
-                .path(request.getRequestURI())
-                .fieldErrors(fieldErrors)
-                .build();
-
-        return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(apiError);
-    }
-
-    @ExceptionHandler({NoHandlerFoundException.class, NoResourceFoundException.class, com.assettrack.exception.ResourceNotFoundException.class})
-    public ResponseEntity<ApiError> handleNotFound(Exception ex, HttpServletRequest request) {
-        return ResponseEntity.status(HttpStatus.NOT_FOUND)
-                .body(buildApiError(HttpStatus.NOT_FOUND, ex.getMessage(), request.getRequestURI()));
-    }
-
-    @ExceptionHandler(HttpMessageNotReadableException.class)
-    public ResponseEntity<ApiError> handleHttpMessageNotReadable(HttpMessageNotReadableException ex, HttpServletRequest request) {
-        return ResponseEntity.status(HttpStatus.BAD_REQUEST)
-                .body(buildApiError(HttpStatus.BAD_REQUEST, "Malformed JSON request", request.getRequestURI()));
-    }
-
-    @ExceptionHandler(EmailAlreadyExistsException.class)
-    public ResponseEntity<ApiError> handleEmailExists(EmailAlreadyExistsException ex, HttpServletRequest request) {
-        return ResponseEntity.status(HttpStatus.CONFLICT)
-                .body(buildApiError(HttpStatus.CONFLICT, ex.getMessage(), request.getRequestURI()));
-    }
-
-    @ExceptionHandler({ConflictException.class})
-    public ResponseEntity<ApiError> handleBadRequest(RuntimeException ex, HttpServletRequest request) {
-        return ResponseEntity.status(HttpStatus.BAD_REQUEST)
-                .body(buildApiError(HttpStatus.BAD_REQUEST, ex.getMessage(), request.getRequestURI()));
-    }
-
-    @ExceptionHandler(BadCredentialsException.class)
-    public ResponseEntity<ApiError> handleBadCredentials(BadCredentialsException ex, HttpServletRequest request) {
-        return ResponseEntity.status(HttpStatus.UNAUTHORIZED)
-                .body(buildApiError(HttpStatus.UNAUTHORIZED, "Invalid email or password", request.getRequestURI()));
-    }
-
-    @ExceptionHandler(AccessDeniedException.class)
-    public ResponseEntity<ApiError> handleAccessDenied(AccessDeniedException ex, HttpServletRequest request) {
-        return ResponseEntity.status(HttpStatus.FORBIDDEN)
-                .body(buildApiError(HttpStatus.FORBIDDEN, "Access denied", request.getRequestURI()));
-    }
-
-    @ExceptionHandler(MethodArgumentTypeMismatchException.class)
-    public ResponseEntity<ApiError> handleTypeMismatch(MethodArgumentTypeMismatchException ex, HttpServletRequest request) {
-        String expectedType = ex.getRequiredType() != null ? ex.getRequiredType().getSimpleName() : "Unknown";
-
-        FieldError fieldError = FieldError.builder()
-                .field(ex.getName())
-                .message(String.format("Type mismatch for parameter: expected type %s", expectedType))
-                .rejectedValue(ex.getValue())
-                .build();
-
-        ApiError apiError = ApiError.builder()
-                .timestamp(Instant.now().toString())
-                .status(HttpStatus.BAD_REQUEST.value())
-                .error(HttpStatus.BAD_REQUEST.getReasonPhrase())
-                .message("Type mismatch")
-                .path(request.getRequestURI())
-                .fieldErrors(Collections.singletonList(fieldError))
-                .build();
-
-        return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(apiError);
-    }
-
-    @ExceptionHandler(HttpRequestMethodNotSupportedException.class)
-    public ResponseEntity<ApiError> handleMethodNotSupported(HttpRequestMethodNotSupportedException ex, HttpServletRequest request) {
-        return ResponseEntity.status(HttpStatus.METHOD_NOT_ALLOWED)
-                .body(buildApiError(HttpStatus.METHOD_NOT_ALLOWED, ex.getMessage(), request.getRequestURI()));
-    }
-
-    @ExceptionHandler(Exception.class)
-    public ResponseEntity<ApiError> handleAllExceptions(Exception ex, HttpServletRequest request) {
-        if (ex instanceof com.assettrack.exception.BaseException baseException) {
-            HttpStatus status = HttpStatus.resolve(baseException.getStatusCode());
-            if (status == null) {
-                status = HttpStatus.INTERNAL_SERVER_ERROR;
-            }
-
-            return ResponseEntity.status(status)
-                    .body(buildApiError(status, baseException.getMessage(), request.getRequestURI()));
+        private ApiError buildApiError(HttpStatus status, String message, String path) {
+                return ApiError.builder()
+                                .timestamp(Instant.now().toString())
+                                .status(status.value())
+                                .error(status.getReasonPhrase())
+                                .message(message)
+                                .path(path)
+                                .build();
         }
 
-        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
-                .body(buildApiError(HttpStatus.INTERNAL_SERVER_ERROR, "An unexpected error occurred", request.getRequestURI()));
-    }
+        @ExceptionHandler(MethodArgumentNotValidException.class)
+        public ResponseEntity<ApiError> handleValidationExceptions(MethodArgumentNotValidException ex,
+                        HttpServletRequest request) {
+                log.warn("Validation failed for {}: {}", request.getRequestURI(), ex.getMessage());
+                List<FieldError> fieldErrors = ex.getBindingResult().getFieldErrors().stream()
+                                .map(error -> FieldError.builder()
+                                                .field(error.getField())
+                                                .message(error.getDefaultMessage())
+                                                .build())
+                                .collect(Collectors.toList());
+
+                ApiError apiError = ApiError.builder()
+                                .timestamp(Instant.now().toString())
+                                .status(HttpStatus.BAD_REQUEST.value())
+                                .error(HttpStatus.BAD_REQUEST.getReasonPhrase())
+                                .message("Validation failed")
+                                .path(request.getRequestURI())
+                                .fieldErrors(fieldErrors)
+                                .build();
+
+                return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(apiError);
+        }
+
+        @ExceptionHandler({ NoHandlerFoundException.class, NoResourceFoundException.class,
+                        com.assettrack.exception.ResourceNotFoundException.class })
+        public ResponseEntity<ApiError> handleNotFound(Exception ex, HttpServletRequest request) {
+                log.warn("Not found at {}: {}", request.getRequestURI(), ex.getMessage());
+                return ResponseEntity.status(HttpStatus.NOT_FOUND)
+                                .body(buildApiError(HttpStatus.NOT_FOUND, ex.getMessage(), request.getRequestURI()));
+        }
+
+        @ExceptionHandler(HttpMessageNotReadableException.class)
+        public ResponseEntity<ApiError> handleHttpMessageNotReadable(HttpMessageNotReadableException ex,
+                        HttpServletRequest request) {
+                log.warn("Malformed JSON at {}", request.getRequestURI(), ex);
+                return ResponseEntity.status(HttpStatus.BAD_REQUEST)
+                                .body(buildApiError(HttpStatus.BAD_REQUEST, "Malformed JSON request",
+                                                request.getRequestURI()));
+        }
+
+        @ExceptionHandler(EmailAlreadyExistsException.class)
+        public ResponseEntity<ApiError> handleEmailExists(EmailAlreadyExistsException ex, HttpServletRequest request) {
+                log.warn("Conflict at {}: {}", request.getRequestURI(), ex.getMessage());
+                return ResponseEntity.status(HttpStatus.CONFLICT)
+                                .body(buildApiError(HttpStatus.CONFLICT, ex.getMessage(), request.getRequestURI()));
+        }
+
+        @ExceptionHandler({ ConflictException.class })
+        public ResponseEntity<ApiError> handleBadRequest(RuntimeException ex, HttpServletRequest request) {
+                log.warn("Bad request at {}: {}", request.getRequestURI(), ex.getMessage());
+                return ResponseEntity.status(HttpStatus.BAD_REQUEST)
+                                .body(buildApiError(HttpStatus.BAD_REQUEST, ex.getMessage(), request.getRequestURI()));
+        }
+
+        @ExceptionHandler(BadCredentialsException.class)
+        public ResponseEntity<ApiError> handleBadCredentials(BadCredentialsException ex, HttpServletRequest request) {
+                log.warn("Unauthorized access at {}", request.getRequestURI());
+                return ResponseEntity.status(HttpStatus.UNAUTHORIZED)
+                                .body(buildApiError(HttpStatus.UNAUTHORIZED, "Invalid email or password",
+                                                request.getRequestURI()));
+        }
+
+        @ExceptionHandler(AccessDeniedException.class)
+        public ResponseEntity<ApiError> handleAccessDenied(AccessDeniedException ex, HttpServletRequest request) {
+                log.warn("Access denied at {}", request.getRequestURI());
+                return ResponseEntity.status(HttpStatus.FORBIDDEN)
+                                .body(buildApiError(HttpStatus.FORBIDDEN, "Access denied", request.getRequestURI()));
+        }
+
+        @ExceptionHandler(MethodArgumentTypeMismatchException.class)
+        public ResponseEntity<ApiError> handleTypeMismatch(MethodArgumentTypeMismatchException ex,
+                        HttpServletRequest request) {
+                String expectedType = ex.getRequiredType() != null ? ex.getRequiredType().getSimpleName() : "Unknown";
+
+                FieldError fieldError = FieldError.builder()
+                                .field(ex.getName())
+                                .message(String.format("Type mismatch for parameter: expected type %s", expectedType))
+                                .rejectedValue(ex.getValue())
+                                .build();
+
+                ApiError apiError = ApiError.builder()
+                                .timestamp(Instant.now().toString())
+                                .status(HttpStatus.BAD_REQUEST.value())
+                                .error(HttpStatus.BAD_REQUEST.getReasonPhrase())
+                                .message("Type mismatch")
+                                .path(request.getRequestURI())
+                                .fieldErrors(Collections.singletonList(fieldError))
+                                .build();
+
+                return ResponseEntity.status(HttpStatus.BAD_REQUEST).body(apiError);
+        }
+
+        @ExceptionHandler(HttpRequestMethodNotSupportedException.class)
+        public ResponseEntity<ApiError> handleMethodNotSupported(HttpRequestMethodNotSupportedException ex,
+                        HttpServletRequest request) {
+                log.warn("Method not supported at {}: {}", request.getRequestURI(), ex.getMethod());
+                return ResponseEntity.status(HttpStatus.METHOD_NOT_ALLOWED)
+                                .body(buildApiError(HttpStatus.METHOD_NOT_ALLOWED, ex.getMessage(),
+                                                request.getRequestURI()));
+        }
+
+        @ExceptionHandler(Exception.class)
+        public ResponseEntity<ApiError> handleAllExceptions(Exception ex, HttpServletRequest request) {
+                if (ex instanceof com.assettrack.exception.BaseException baseException) {
+                        HttpStatus status = HttpStatus.resolve(baseException.getStatusCode());
+                        if (status == null) {
+                                status = HttpStatus.INTERNAL_SERVER_ERROR;
+                        }
+
+                        log.warn("Application exception at {}: {}", request.getRequestURI(),
+                                        baseException.getMessage());
+
+                        return ResponseEntity.status(status)
+                                        .body(buildApiError(status, baseException.getMessage(),
+                                                        request.getRequestURI()));
+                }
+
+                log.error("Unexpected exception at {}", request.getRequestURI(), ex);
+                return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
+                                .body(buildApiError(HttpStatus.INTERNAL_SERVER_ERROR, "An unexpected error occurred",
+                                                request.getRequestURI()));
+        }
 }

backend/src/main/java/com/assettrack/common/exception/dto/ApiError.java

@@ -8,6 +8,9 @@
 
 import java.util.List;
 
+/**
+ * Standard error envelope returned by the global exception handler.
+ */
 @Data
 @Builder
 @NoArgsConstructor

backend/src/main/java/com/assettrack/common/exception/dto/ErrorResponse.java

@@ -5,6 +5,9 @@
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
+/**
+ * Legacy error response envelope kept for backward compatibility.
+ */
 @Data
 @Builder
 @NoArgsConstructor

backend/src/main/java/com/assettrack/common/exception/dto/FieldError.java

@@ -1,16 +1,17 @@
 package com.assettrack.common.exception.dto;
 
-import com.fasterxml.jackson.annotation.JsonInclude;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
+/**
+ * Validation failure details for a single field.
+ */
 @Data
 @Builder
 @NoArgsConstructor
 @AllArgsConstructor
-@JsonInclude(JsonInclude.Include.NON_NULL)
 public class FieldError {
     private String field;
     private String message;

backend/src/main/java/com/assettrack/common/exception/dto/ValidationErrorDetail.java

@@ -5,6 +5,9 @@
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
+/**
+ * Detailed validation error entry used by legacy responses.
+ */
 @Data
 @Builder
 @NoArgsConstructor

backend/src/main/java/com/assettrack/common/exception/dto/ValidationErrorResponse.java

@@ -7,6 +7,9 @@
 
 import java.util.List;
 
+/**
+ * Legacy validation error response envelope.
+ */
 @Data
 @Builder
 @NoArgsConstructor

backend/src/main/java/com/assettrack/config/OpenApiConfig.java

@@ -13,33 +13,38 @@
 
 import java.util.List;
 
+/**
+ * OpenAPI configuration for the AssetTrack API documentation.
+ */
 @Configuration
 public class OpenApiConfig {
 
-    @Bean
-    public OpenAPI assetTrackOpenAPI() {
-        return new OpenAPI()
-                .info(new Info()
-                        .title("AssetTrack API")
-                        .description("IT Asset Management and Tracking System API. " +
-                                "Provides endpoints for managing assets, allocations, users, " +
-                                "authentication, dashboard analytics, and notifications.")
-                        .version("0.1.0")
-                        .contact(new Contact()
-                                .name("AssetTrack Team")
-                                .email("admin@assettrack.com"))
-                        .license(new License()
-                                .name("MIT License")
-                                .url("https://opensource.org/licenses/MIT")))
-                .servers(List.of(
-                        new Server().url("http://localhost:8080").description("Local Development")))
-                .addSecurityItem(new SecurityRequirement().addList("Bearer Authentication"))
-                .components(new Components()
-                        .addSecuritySchemes("Bearer Authentication",
-                                new SecurityScheme()
-                                        .type(SecurityScheme.Type.HTTP)
-                                        .scheme("bearer")
-                                        .bearerFormat("JWT")
-                                        .description("Enter your JWT token")));
-    }
+        @Bean
+        public OpenAPI assetTrackOpenAPI() {
+                return new OpenAPI()
+                                .info(new Info()
+                                                .title("AssetTrack API")
+                                                .description("IT Asset Management and Tracking System API. " +
+                                                                "Provides endpoints for managing assets, allocations, users, "
+                                                                +
+                                                                "authentication, dashboard analytics, and notifications.")
+                                                .version("0.1.0")
+                                                .contact(new Contact()
+                                                                .name("AssetTrack Team")
+                                                                .email("admin@assettrack.com"))
+                                                .license(new License()
+                                                                .name("MIT License")
+                                                                .url("https://opensource.org/licenses/MIT")))
+                                .servers(List.of(
+                                                new Server().url("http://localhost:8080")
+                                                                .description("Local Development")))
+                                .addSecurityItem(new SecurityRequirement().addList("Bearer Authentication"))
+                                .components(new Components()
+                                                .addSecuritySchemes("Bearer Authentication",
+                                                                new SecurityScheme()
+                                                                                .type(SecurityScheme.Type.HTTP)
+                                                                                .scheme("bearer")
+                                                                                .bearerFormat("JWT")
+                                                                                .description("Enter your JWT token")));
+        }
 }