de.whs.poodle.PoodleErrorAttributes.java Source code

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Here is the source code for de.whs.poodle.PoodleErrorAttributes.java

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/*
 * Copyright 2015 Westflische Hochschule
 *
 * This file is part of Poodle.
 *
 * Poodle is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Poodle is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with Poodle.  If not, see <http://www.gnu.org/licenses/>.
 */
package de.whs.poodle;

import java.util.HashMap;
import java.util.Locale;
import java.util.Map;

import javax.servlet.RequestDispatcher;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.web.DefaultErrorAttributes;
import org.springframework.context.MessageSource;
import org.springframework.context.i18n.LocaleContextHolder;
import org.springframework.http.HttpStatus;
import org.springframework.jdbc.CannotGetJdbcConnectionException;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestAttributes;

import de.whs.poodle.repositories.exceptions.RepositoryException;

/*
 * Overrides the DefaultErrorAttributes by Spring, so that Exceptions
 * are always logged and we only return the variables "status" and "message,
 *
 * Depending on whether the client makes an HTML or Ajax-Request, Spring automatically
 * either forwards to error.html or returns the variables as a JSON object.
 *
 * see also Spring's BasicErrorController and
 * http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-error-handling
 */
@Component
public class PoodleErrorAttributes extends DefaultErrorAttributes {

    private static Logger log = LoggerFactory.getLogger(PoodleErrorAttributes.class);

    @Autowired
    private MessageSource messageSource;

    @Override
    public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes, boolean includeStackTrace) {
        Map<String, Object> errorAttributes = new HashMap<>();

        Throwable error = getError(requestAttributes);

        String message = null;

        if (error != null) {
            /* RepositoryExceptions contain messageCodes for localization.
             * If the error was a RepositoryException, create the corresponding
             * text with the messageSource. We use this a lot with
             * BadRequestException to localize responses to the client. */
            if (error instanceof RepositoryException) {
                RepositoryException daoExc = (RepositoryException) error;
                if (daoExc.getMessageCode() != null) {
                    Locale locale = LocaleContextHolder.getLocale();
                    message = messageSource.getMessage(daoExc.getMessageCode(), daoExc.getMessageCodeArgs(),
                            locale);
                }
            }

            // show a more specific error on database connection failures
            if (error instanceof CannotGetJdbcConnectionException)
                message = "error connecting to database (" + error.getMessage() + ")";

            log.error("Error", error);
        }

        int status = (int) requestAttributes.getAttribute(RequestDispatcher.ERROR_STATUS_CODE,
                RequestAttributes.SCOPE_REQUEST);

        if (message == null)
            message = HttpStatus.valueOf(status).getReasonPhrase();

        errorAttributes.put("status", status);
        errorAttributes.put("message", message);

        return errorAttributes;
    }
}