ResultAbstractAction.java

/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2011, Red Hat Middleware LLC, and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jboss.capedwarf.server.api.mvc;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.logging.Level;

/**
 * Result abstract action.
 *
 * @param <R> exact result type
 * @author <a href="mailto:ales.justin@jboss.org">Ales Justin</a>
 */
public abstract class ResultAbstractAction<R> extends AbstractAction {
    private boolean suppressException = true;

    /**
     * Do handle request and response.
     *
     * @param req  the request
     * @param resp the response
     * @return true if the action was successful, false otherwise
     * @throws javax.servlet.ServletException for any servlet error
     * @throws java.io.IOException            for any I/O error
     */
    protected abstract R doHandle(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException;

    public void handle(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        try {
            R result = doHandle(req, resp);
            doWriteResult(resp, result);
        } catch (ServletException e) {
            handle(resp, e);
        } catch (IOException e) {
            handle(resp, e);
        } catch (RuntimeException e) {
            handle(resp, e);
        }
    }

    protected void doWriteResult(HttpServletResponse resp, R result) throws IOException {
        writeResult(resp, result);
    }

    protected abstract R errorResult();

    private <T extends Throwable> void handle(HttpServletResponse resp, T t) throws T {
        if (suppressException) {
            try {
                log.log(Level.WARNING, "Ignoring exception.", t);
                doWriteResult(resp, errorResult());
            } catch (IOException ignored) {
            }
        } else {
            throw t;
        }
    }

    public void setSuppressException(boolean suppressException) {
        this.suppressException = suppressException;
    }
}