Add at least one field not null validator

src/main/java/net/kapcake/bankingservice/model/dtos/PaymentFilter.java

@@ -3,12 +3,14 @@ package net.kapcake.bankingservice.model.dtos;
 import jakarta.validation.constraints.AssertTrue;
 import lombok.Data;
 import lombok.experimental.Accessors;
+import net.kapcake.bankingservice.validation.AtLeastOneFieldNotEmpty;
 
 import java.io.Serializable;
 import java.util.Date;
 
 @Data
 @Accessors(chain = true)
+@AtLeastOneFieldNotEmpty(fieldNames = {"beneficiaryAccountNumber", "startDate", "endDate"})
 public class PaymentFilter implements Serializable {
 
     private String beneficiaryAccountNumber;
@@ -23,11 +25,4 @@ public class PaymentFilter implements Serializable {
             return startDate.compareTo(endDate) <= 0;
         }
     }
-
-    @AssertTrue(message = "At least one field needs to be supplied")
-    public boolean isAtLeastOneFieldFilled() {
-        return startDate != null ||
-                endDate != null ||
-                (beneficiaryAccountNumber != null && !beneficiaryAccountNumber.isBlank());
-    }
 }

src/main/java/net/kapcake/bankingservice/validation/AtLeastOneFieldNotEmpty.java

@@ -0,0 +1,20 @@
+package net.kapcake.bankingservice.validation;
+
+import jakarta.validation.Constraint;
+import jakarta.validation.Payload;
+
+import java.lang.annotation.*;
+
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+@Constraint(validatedBy = AtLeastOneFieldNotEmptyValidator.class)
+@Documented
+public @interface AtLeastOneFieldNotEmpty {
+    String message() default "At least one field needs to be supplied";
+
+    String[] fieldNames();
+
+    Class<?>[] groups() default {};
+
+    Class<? extends Payload>[] payload() default {};
+}

src/main/java/net/kapcake/bankingservice/validation/AtLeastOneFieldNotEmptyValidator.java

@@ -0,0 +1,34 @@
+package net.kapcake.bankingservice.validation;
+
+import jakarta.validation.ConstraintValidator;
+import jakarta.validation.ConstraintValidatorContext;
+import org.springframework.beans.BeanUtils;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.Arrays;
+
+public class AtLeastOneFieldNotEmptyValidator implements ConstraintValidator<AtLeastOneFieldNotEmpty, Object> {
+    private String[] fieldNames;
+
+    @Override
+    public void initialize(AtLeastOneFieldNotEmpty constraintAnnotation) {
+        this.fieldNames = constraintAnnotation.fieldNames();
+    }
+
+    @Override
+    public boolean isValid(Object obj, ConstraintValidatorContext context) {
+        if (obj == null) {
+            return false;
+        }
+        Object[] fieldValues = new Object[fieldNames.length];
+        try {
+            for (int i = 0; i < fieldValues.length; i++) {
+                fieldValues[i] = BeanUtils.getPropertyDescriptor(obj.getClass(), fieldNames[i]).getReadMethod().invoke(obj);
+            }
+        } catch (InvocationTargetException | IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+        boolean isEveryValueNullOrEmpty = Arrays.stream(fieldValues).allMatch(value -> value == null || (value instanceof String) && ((String) value).isBlank());
+        return !isEveryValueNullOrEmpty;
+    }
+}