ServiceResponse

ServiceResponse.java

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.Data;
import org.springframework.validation.ObjectError;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

@Data
public class ServiceResponse<T> {
    private final List<ObjectError> validationErrors = new ArrayList<>();
    private T data;
    private String message;

    // Getters and setters

    public List<String> getErrorMessages() {
        List<String> result = new ArrayList<>();
        for (ObjectError error : validationErrors) {
            result.add(error.getDefaultMessage());
        }
        return result.isEmpty() ? null : result;
    }

    public List<String> getModelStateErrors(Map<String, List<ObjectError>> modelState) {
        List<String> result = new ArrayList<>();
        for (List<ObjectError> errors : modelState.values()) {
            for (ObjectError error : errors) {
                result.add(error.getDefaultMessage());
            }
        }
        return result.isEmpty() ? null : result;
    }

    public boolean hasError() {
        return !validationErrors.isEmpty();
    }

    public void addError(String error) {
        validationErrors.add(new ObjectError("", error));
    }

    public void addError(ObjectError validationResult) {
        validationErrors.add(validationResult);
    }

    public void addError(List<ObjectError> validationResults) {
        validationErrors.addAll(validationResults);
    }

    @Override
    public String toString() {
        ObjectMapper mapper = new ObjectMapper();
        try {
            return mapper.writeValueAsString(this);
        } catch (JsonProcessingException e) {
            throw new RuntimeException(e);
        }
    }
}