Feature/input validation - Close #6

pom.xml

@@ -44,6 +44,10 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-actuator</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
 
         <!-- Swagger -->
         <dependency>

src/main/java/com/seyed/ali/timeentryservice/annotation/OptionalField.java

@@ -0,0 +1,47 @@
+package com.seyed.ali.timeentryservice.annotation;
+
+import jakarta.validation.Constraint;
+import jakarta.validation.Payload;
+
+import java.lang.annotation.*;
+
+/**
+ * Annotation to mark fields as optional for validation purposes.
+ * Fields annotated with {@code @OptionalField} are considered optional,
+ * allowing users to omit these fields in their input without triggering validation errors.
+ * <p>
+ * This annotation should be used in conjunction with a custom validator to enforce the optional behavior.
+ * </p>
+ *
+ * @author [Seyed Ali]
+ * @since 0.1
+ */
+@Target({ElementType.FIELD})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+@Constraint(validatedBy = OptionalFieldValidator.class)
+public @interface OptionalField {
+
+    /**
+     * Returns the error message template.
+     *
+     * @return the error message template
+     */
+    String message() default "Field is optional";
+
+    /**
+     * Returns the groups the constraint belongs to.
+     *
+     * @return the groups the constraint belongs to
+     */
+    Class<?>[] groups() default {};
+
+    /**
+     * Returns the payload associated with the constraint.
+     *
+     * @return the payload associated with the constraint
+     */
+    Class<? extends Payload>[] payload() default {};
+
+}
+

src/main/java/com/seyed/ali/timeentryservice/annotation/OptionalFieldValidator.java

@@ -0,0 +1,33 @@
+package com.seyed.ali.timeentryservice.annotation;
+
+import jakarta.validation.ConstraintValidator;
+import jakarta.validation.ConstraintValidatorContext;
+
+/**
+ * Custom validator for the {@link OptionalField} annotation.
+ * <p>
+ * This validator checks whether a field annotated with {@code @OptionalField} is optional or not.
+ * The field is considered optional if its value is null or an empty string ("").
+ * </p>
+ *
+ * @author [Seyed Ali]
+ * @since 0.1
+ */
+public class OptionalFieldValidator implements ConstraintValidator<OptionalField, Object> {
+
+    /**
+     * Checks whether the given value is valid.
+     * The value is considered valid if it is null or an empty string ("").
+     *
+     * @param value   The value to validate
+     * @param context The constraint validator context
+     * @return {@code true}, indicating that the field is optional and considered valid.
+     * Otherwise, it returns {@code false}, indicating that the field has a value and should be validated according to other constraints
+     */
+    @Override
+    public boolean isValid(Object value, ConstraintValidatorContext context) {
+        return value == null || (value instanceof String && ((String) value).isEmpty());
+    }
+
+}
+

src/main/java/com/seyed/ali/timeentryservice/controller/TimeEntryController.java

@@ -10,6 +10,7 @@
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
@@ -52,7 +53,7 @@ public ResponseEntity<Result> getUsersTimeEntry(@PathVariable String userId) {
     }
 
     @PostMapping
-    public ResponseEntity<Result> addTimeEntryManually(@RequestBody TimeEntryDTO timeEntryDTO) {
+    public ResponseEntity<Result> addTimeEntryManually(@Valid @RequestBody TimeEntryDTO timeEntryDTO) {
         return ResponseEntity.status(CREATED).body(new Result(
                 true,
                 CREATED,
@@ -62,7 +63,7 @@ public ResponseEntity<Result> addTimeEntryManually(@RequestBody TimeEntryDTO tim
     }
 
     @PutMapping("/{timeEntryId}")
-    public ResponseEntity<Result> updateTimeEntryManually(@PathVariable String timeEntryId, @RequestBody TimeEntryDTO timeEntryDTO) {
+    public ResponseEntity<Result> updateTimeEntryManually(@Valid @PathVariable String timeEntryId, @RequestBody TimeEntryDTO timeEntryDTO) {
         return ResponseEntity.ok(new Result(
                 true,
                 OK,

src/main/java/com/seyed/ali/timeentryservice/controller/TimeEntryTrackingController.java

@@ -4,6 +4,7 @@
 import com.seyed.ali.timeentryservice.model.dto.response.Result;
 import com.seyed.ali.timeentryservice.service.interfaces.TimeEntryTrackingService;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
+import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
@@ -22,9 +23,14 @@ public class TimeEntryTrackingController {
     private final TimeEntryTrackingService timeEntryService;
 
     @PostMapping("/start")
-    public ResponseEntity<Result> startTrackingTimeEntry(@RequestBody TimeBillingDTO timeBillingDTO) {
-        boolean billable = timeBillingDTO.isBillable();
-        BigDecimal hourlyRate = timeBillingDTO.getHourlyRate();
+    public ResponseEntity<Result> startTrackingTimeEntry(@Valid @RequestBody TimeBillingDTO timeBillingDTO) {
+        boolean billable = false;
+        BigDecimal hourlyRate = BigDecimal.ZERO;
+
+        if (timeBillingDTO != null) {
+            billable = timeBillingDTO.billable();
+            hourlyRate = timeBillingDTO.hourlyRate();
+        }
         return ResponseEntity.status(CREATED).body(new Result(
                 true,
                 CREATED,

src/main/java/com/seyed/ali/timeentryservice/exceptions/handler/TimeEntryServiceHandlerAdvice.java

@@ -1,15 +1,24 @@
 package com.seyed.ali.timeentryservice.exceptions.handler;
 
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.databind.JsonMappingException;
 import com.seyed.ali.timeentryservice.exceptions.OperationNotSupportedException;
 import com.seyed.ali.timeentryservice.exceptions.ResourceNotFoundException;
 import com.seyed.ali.timeentryservice.model.dto.response.Result;
 import org.springframework.http.ResponseEntity;
+import org.springframework.http.converter.HttpMessageNotReadableException;
 import org.springframework.security.access.AccessDeniedException;
+import org.springframework.validation.FieldError;
+import org.springframework.validation.ObjectError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RestControllerAdvice;
 
-import static org.springframework.http.HttpStatus.FORBIDDEN;
-import static org.springframework.http.HttpStatus.NOT_FOUND;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import static org.springframework.http.HttpStatus.*;
 
 @RestControllerAdvice
 public class TimeEntryServiceHandlerAdvice {
@@ -44,4 +53,41 @@ public ResponseEntity<Result> handleOperationNotSupportedException(OperationNotS
         ));
     }
 
+    @ExceptionHandler({MethodArgumentNotValidException.class})
+    public ResponseEntity<Result> handleMethodArgumentNotValidException(MethodArgumentNotValidException e) {
+        List<ObjectError> allErrors = e.getBindingResult().getAllErrors();
+        Map<String, String> map = new HashMap<>(allErrors.size());
+        allErrors.forEach(objectError -> {
+            String defaultMessage = objectError.getDefaultMessage();
+            String field = ((FieldError) objectError).getField();
+            map.put(field, defaultMessage);
+        });
+
+        return ResponseEntity.status(BAD_REQUEST).body(new Result(
+                false,
+                BAD_REQUEST,
+                "Provided arguments are invalid, see data for details.",
+                map
+        ));
+    }
+
+    @ExceptionHandler({HttpMessageNotReadableException.class})
+    public ResponseEntity<Result> handleHttpMessageNotReadableException(HttpMessageNotReadableException e) {
+        String errorMessage = "Invalid request format. Please check your request and try again.";
+        Throwable cause = e.getCause();
+
+        if (cause instanceof JsonParseException jsonParseException) {
+            errorMessage = "JSON parse error: " + jsonParseException.getOriginalMessage();
+        } else if (cause instanceof JsonMappingException jsonMappingException) {
+            errorMessage = "JSON mapping error at " + jsonMappingException.getPathReference() + ": " + jsonMappingException.getOriginalMessage();
+        }
+
+        return ResponseEntity.status(BAD_REQUEST).body(new Result(
+                false,
+                BAD_REQUEST,
+                errorMessage,
+                e.getMessage()
+        ));
+    }
+
 }

src/main/java/com/seyed/ali/timeentryservice/model/domain/TimeEntry.java

@@ -24,7 +24,7 @@ public class TimeEntry {
     @Builder.Default
     private boolean billable = false;
     @Builder.Default
-    private BigDecimal hourlyRate = BigDecimal.TEN;
+    private BigDecimal hourlyRate = BigDecimal.ZERO;
 
     @OneToMany(mappedBy = "timeEntry", cascade = CascadeType.ALL)
     @ToString.Exclude

src/main/java/com/seyed/ali/timeentryservice/model/dto/TimeBillingDTO.java

@@ -1,19 +1,24 @@
 package com.seyed.ali.timeentryservice.model.dto;
 
-import lombok.AllArgsConstructor;
+import com.seyed.ali.timeentryservice.model.domain.TimeEntry;
+import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.constraints.DecimalMax;
+import jakarta.validation.constraints.DecimalMin;
 import lombok.Builder;
-import lombok.Data;
-import lombok.NoArgsConstructor;
 
 import java.math.BigDecimal;
 
-@Data
+/**
+ * DTO for {@link TimeEntry}
+ */
 @Builder
-@NoArgsConstructor
-@AllArgsConstructor
-public class TimeBillingDTO {
-
-    private boolean billable;
-    private BigDecimal hourlyRate;
+public record TimeBillingDTO(
+        @Schema(requiredMode = Schema.RequiredMode.NOT_REQUIRED, description = "A flag determining this time entry is billable", example = "true")
+        boolean billable,
 
+        @Schema(requiredMode = Schema.RequiredMode.NOT_REQUIRED, description = "The hourly rate in BigDecimal format", example = "10.0")
+        @DecimalMin(value = "0.0", inclusive = false, message = "hourlyRate must be greater than 0")
+        @DecimalMax(value = "999.99", message = "hourlyRate must be less than 1000")
+        BigDecimal hourlyRate
+) {
 }

src/main/java/com/seyed/ali/timeentryservice/model/dto/TimeEntryDTO.java

@@ -1,25 +1,39 @@
 package com.seyed.ali.timeentryservice.model.dto;
 
+import com.seyed.ali.timeentryservice.annotation.OptionalField;
+import com.seyed.ali.timeentryservice.model.domain.TimeEntry;
 import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.constraints.*;
 
+/**
+ * DTO for {@link TimeEntry}
+ */
 @Schema(description = "Time Entry Data Transfer Object")
 public record TimeEntryDTO(
         @Schema(requiredMode = Schema.RequiredMode.NOT_REQUIRED, description = "Unique identifier for the time entry", example = "12345")
+        @Size(max = 36, message = "timeEntryId must be maximum 36 characters")
         String timeEntryId,
 
         @Schema(requiredMode = Schema.RequiredMode.REQUIRED, description = "Start time of the time entry in the format yyyy-MM-dd HH:mm", example = "2024-05-12 08:00:00")
+        @NotBlank(message = "startTime is mandatory") @Pattern(regexp = "^\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2}$", message = "startTime must be in the format yyyy-MM-dd HH:mm:ss")
         String startTime,
 
         @Schema(requiredMode = Schema.RequiredMode.REQUIRED, description = "End time of the time entry in the format yyyy-MM-dd HH:mm", example = "2024-05-12 10:00:00")
+        @NotBlank(message = "endTime is mandatory")
+        @Pattern(regexp = "^\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2}$", message = "endTime must be in the format yyyy-MM-dd HH:mm:ss")
         String endTime,
 
         @Schema(requiredMode = Schema.RequiredMode.NOT_REQUIRED, description = "A flag determining this time entry is billable", example = "true")
         boolean billable,
 
         @Schema(requiredMode = Schema.RequiredMode.NOT_REQUIRED, description = "The hourly rate in BigDecimal format", example = "10.0")
+        @DecimalMin(value = "0.0", inclusive = false, message = "hourlyRate must be greater than 0")
+        @DecimalMax(value = "999.99", message = "hourlyRate must be less than 1000")
+        @OptionalField
         String hourlyRate,
 
         @Schema(requiredMode = Schema.RequiredMode.AUTO, description = "Duration of the time entry in the format HH:mm:ss", example = "02:00:00")
+        @Pattern(regexp = "^\\d{2}:\\d{2}:\\d{2}$", message = "duration must be in the format HH:mm:ss")
         String duration
 ) {
 }

src/main/java/com/seyed/ali/timeentryservice/model/dto/TimeSegmentDTO.java

@@ -1,12 +1,13 @@
 package com.seyed.ali.timeentryservice.model.dto;
 
+import com.seyed.ali.timeentryservice.model.domain.TimeSegment;
 import io.swagger.v3.oas.annotations.media.Schema;
 import lombok.Builder;
 
 import java.io.Serializable;
 
 /**
- * DTO for {@link com.seyed.ali.timeentryservice.model.domain.TimeSegment}
+ * DTO for {@link TimeSegment}
  */
 @Schema
 @Builder