Implement CurrentYear validator

Signed-off-by: Pekka Helenius <fincer89@hotmail.com>

bookstore/src/main/java/com/fjordtek/bookstore/validation/CurrentYear.java

@@ -0,0 +1,24 @@
+//Pekka Helenius <fincer89@hotmail.com>, Fjordtek 2020
+
+package com.fjordtek.bookstore.validation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.annotation.ElementType;
+
+import javax.validation.Constraint;
+import javax.validation.Payload;
+
+@Documented
+@Constraint(validatedBy = CurrentYearValidator.class)
+@Target(value={ElementType.TYPE_USE, ElementType.ANNOTATION_TYPE, ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER})
+@Retention(RetentionPolicy.RUNTIME)
+
+public @interface CurrentYear {
+	String message() default "Year must not be in the future";
+	Class<?>[] groups() default { };
+	Class<? extends Payload>[] payload() default { };
+
+}

bookstore/src/main/java/com/fjordtek/bookstore/validation/CurrentYearValidator.java

@@ -0,0 +1,25 @@
+//Pekka Helenius <fincer89@hotmail.com>, Fjordtek 2020
+
+package com.fjordtek.bookstore.validation;
+
+import java.time.Year;
+
+import javax.validation.ConstraintValidator;
+import javax.validation.ConstraintValidatorContext;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class CurrentYearValidator implements ConstraintValidator<CurrentYear, Integer> {
+	
+	private static final int yearNow = Year.now().getValue();
+	
+	@Override
+    public void initialize(CurrentYear year) {
+    }
+	
+	@Override
+	public boolean isValid(Integer year, ConstraintValidatorContext constraintValidatorContext) {
+		return year <= yearNow;
+	}
+}