de.metas.procurement.webui.server.AbstractErrorHandler.java Source code

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Here is the source code for de.metas.procurement.webui.server.AbstractErrorHandler.java

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package de.metas.procurement.webui.server;

import java.net.SocketException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.vaadin.spring.i18n.I18N;

import com.vaadin.server.AbstractErrorMessage;
import com.vaadin.server.DefaultErrorHandler;
import com.vaadin.server.ErrorEvent;
import com.vaadin.server.ErrorHandler;
import com.vaadin.server.ErrorMessage;
import com.vaadin.server.SystemError;
import com.vaadin.server.UserError;

import de.metas.procurement.webui.Application;

/*
 * #%L
 * de.metas.procurement.webui
 * %%
 * Copyright (C) 2016 metas GmbH
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 2 of the
 * License, or (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-2.0.html>.
 * #L%
 */

/**
 * Base class for implementing specific {@link ErrorHandler}s.
 * 
 * @author metas-dev <dev@metas-fresh.com>
 *
 */
@SuppressWarnings("serial")
public abstract class AbstractErrorHandler implements com.vaadin.server.ErrorHandler {
    @Autowired
    private I18N i18n;

    private final transient Logger logger = LoggerFactory.getLogger(getClass());

    public AbstractErrorHandler() {
        super();
        Application.autowire(this);
    }

    @Override
    public final void error(final ErrorEvent event) {
        //
        // Extract the relevant exception
        Throwable t = event.getThrowable();
        if (t instanceof SocketException) {
            // Most likely client browser closed socket
            logger.info("SocketException in CommunicationManager. Most likely client (browser) closed socket.");
            return;
        }
        t = DefaultErrorHandler.findRelevantThrowable(t);

        //
        // Create error message
        final ErrorMessage errorMessage = createErrorMessage(t);

        //
        // Display it
        displayError(errorMessage, event);

        // also print the error on console
        logger.error("", t);
    }

    /**
     * Displays the given error message.
     * 
     * @param errorMessage error message to be displayed
     * @param event original error event
     */
    protected abstract void displayError(final ErrorMessage errorMessage, final ErrorEvent event);

    private ErrorMessage createErrorMessage(final Throwable t) {
        final ErrorMessage errorMessage = AbstractErrorMessage.getErrorMessageForException(t);

        // In case we deal with an System Error, don't show it to user because it's confusing.
        // Instead show a generic friendly error message.
        if (errorMessage instanceof SystemError) {
            return new UserError(i18n.get("error.default"));
        }

        return errorMessage;
    }
}