[spring 20편] spring validate custom (spel 이용해서 validate 수행할지 결정)

source 는 Github 에 있습니다.

목차는 spring series 목차 에 있습니다.

[spring 20편] spring validate custom (spel 이용해서 validate 수행할지 결정)

spring validation custom

• spel (Spring Expression Language) 을 이용해서 validate 을 수행할지 안할지를 결정하는 예제입니다.
• 소스를 간략히 설명하면 ItemConstraint 를 선언하면 validation 이 수행됩니다. 이 때, condition 조건에 따라 validate 를 수행할지 안할지를 결정할 수 있습니다.
• condition 조건은 spel (Spring Expression Language) 을 이용해서 제한적으로 체크합니다. (추후 보완하겠습니다.)

source

• 테스트 예시를 하나 들어보면 testItemConstraintValidatorTest01 테스트는 조건을(condition) 먼저 체크합니다.
• condition = "id =='ItemId'" --> parameter id 값이 "ItemId" 일 경우 validate 를 진행하겠다는 것입니다.
• 비교할 필드는 "desc" 라는 필드이며, 해당 필드의 값이 compareValue 와 동일할 경우 validate 통과합니다.

	// build.gradle
	implementation 'org.springframework.boot:spring-boot-starter-validation'
	// ItemConstraint.java
	@Documented
	@Retention(RUNTIME)
	@Target({METHOD, FIELD, TYPE})
	@Constraint(validatedBy = ItemConstraintValidator.class)
	public @interface ItemConstraint {
	String message() default "Invalid...";
	String compareValue();
	String field();
	String condition();
	Class<?>[] groups() default {};
	Class<? extends Payload>[] payload() default {};
	}
	// ItemConstraintValidator.java
	@Slf4j
	public class ItemConstraintValidator implements ConstraintValidator<ItemConstraint, Object> {
	private Expression conditionExpression;
	private String compareValue;
	private String fieldName;
	@Override
	public void initialize(ItemConstraint itemConstraint) {
	String condition = itemConstraint.condition();
	ExpressionParser parser = new SpelExpressionParser();
	if (StringUtils.hasText(condition)) {
	conditionExpression = parser.parseExpression(condition);
	}
	this.compareValue = StringUtils.hasText(itemConstraint.compareValue()) ?
	itemConstraint.compareValue() : "";
	this.fieldName = StringUtils.hasText(itemConstraint.field()) ? itemConstraint.field() : "";
	}
	@Override
	public boolean isValid(Object object, ConstraintValidatorContext context) {
	EvaluationContext evaluationContext = createEvaluationContext(object);
	if (ObjectUtils.isEmpty(object) || !isConditionPassing(evaluationContext)) {
	return true;
	}
	log.info("pass condition... start validate constraint...");
	return getFieldValue(object).equals(compareValue);
	}
	private Object getFieldValue(Object value) {
	try {
	Field field = ReflectionUtils.findField(value.getClass(), fieldName);
	field.setAccessible(true);
	return field.get(value);
	} catch (Exception e) {
	log.error(e.getMessage(), e);
	throw new RuntimeException(e);
	}
	}
	private boolean isConditionPassing(EvaluationContext evaluationContext) {
	if (ObjectUtils.isEmpty(conditionExpression)) {
	return true;
	}
	Boolean isCOnditionPassing = conditionExpression.getValue(evaluationContext, Boolean.class);
	return ObjectUtils.isEmpty(isCOnditionPassing) ? false : isCOnditionPassing;
	}
	private StandardEvaluationContext createEvaluationContext(Object value) {
	StandardEvaluationContext context = new StandardEvaluationContext();
	context.setRootObject(value);
	return context;
	}
	}
	// ItemConstraintValidatorTest.java
	class ItemConstraintValidatorTest {
	@ParameterizedTest
	@CsvSource({
	"ItemId, ItemDesc, true", // pass condition --> valid compareValue
	"ItemId, ItemDesc22, false" // pass condition --> invalid compareValue
	})
	@DisplayName("ItemCommandRequest 로 테스트")
	void testItemConstraintValidatorTest01(String id, String desc, boolean expected)
	throws NoSuchFieldException, IllegalAccessException {
	var request = ItemCommandRequest.builder()
	.id(id)
	.desc(desc)
	.build();
	var validator = new ItemConstraintValidator();
	var itemConstraint = request.getClass().getAnnotation(ItemConstraint.class);
	validator.initialize(itemConstraint);
	Assertions.assertEquals(expected, validator.isValid(request, getConstraintValidatorContext()));
	}
	@ParameterizedTest
	@CsvSource({
	"ItemId, Item123, true, false", // pass condition --> invalid compareValue
	"ItemId, Item234, false, true" // not pass condition
	})
	@DisplayName("ItemCommandRequest2 로 테스트")
	void testItemConstraintValidatorTest02(String id, String desc, boolean next, boolean expected)
	throws NoSuchFieldException, IllegalAccessException {
	var request = ItemCommandRequest2.builder()
	.id(id)
	.desc(desc)
	.next(next)
	.build();
	var validator = new ItemConstraintValidator();
	var itemConstraint = request.getClass().getAnnotation(ItemConstraint.class);
	validator.initialize(itemConstraint);
	Assertions.assertEquals(expected, validator.isValid(request, getConstraintValidatorContext()));
	}
	@Data
	@Builder
	@AllArgsConstructor
	@NoArgsConstructor
	@ItemConstraint(compareValue = "ItemDesc", field = "desc", condition = "id == 'ItemId'")
	public static class ItemCommandRequest {
	private String id;
	private String desc;
	}
	@Data
	@Builder
	@AllArgsConstructor
	@NoArgsConstructor
	@ItemConstraint(compareValue = "ItemDesc", field = "desc", condition = "id == 'ItemId' && next")
	public static class ItemCommandRequest2 {
	private String id;
	private String desc;
	private boolean next;
	}
	private ConstraintValidatorContext getConstraintValidatorContext() {
	return new ConstraintValidatorContext() {
	@Override
	public void disableDefaultConstraintViolation() {
	}
	@Override
	public String getDefaultConstraintMessageTemplate() {
	return null;
	}
	@Override
	public ClockProvider getClockProvider() {
	return null;
	}
	@Override
	public ConstraintViolationBuilder buildConstraintViolationWithTemplate(String messageTemplate) {
	return null;
	}
	@Override
	public <T> T unwrap(Class<T> type) {
	return null;
	}
	};
	}
	}

view raw SpringValidateBySpel.java hosted with ❤ by GitHub