Major system rework

src/main/java/at/pcgamingfreaks/mkvaudiosubtitlechanger/impl/validation/ValidFile.java

@@ -0,0 +1,16 @@
+package at.pcgamingfreaks.mkvaudiosubtitlechanger.impl.validation;
+
+import jakarta.validation.Constraint;
+import jakarta.validation.Payload;
+
+import java.lang.annotation.*;
+
+@Documented
+@Constraint(validatedBy = ValidFileValidator.class)
+@Target({ElementType.METHOD, ElementType.FIELD})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface ValidFile {
+    String message() default "File does not exist";
+    Class<?>[] groups() default {};
+    Class<? extends Payload>[] payload() default {};
+}