SCM-Manager/scm-webapp/src/main/java/sonia/scm/template/ErrorServlet.java

/**
 * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer. 2. Redistributions in
 * binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other
 * materials provided with the distribution. 3. Neither the name of SCM-Manager;
 * nor the names of its contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * http://bitbucket.org/sdorra/scm-manager
 *
 */



package sonia.scm.template;

//~--- non-JDK imports --------------------------------------------------------

import com.google.common.base.Throwables;
import com.google.inject.Inject;
import com.google.inject.Singleton;

import sonia.scm.SCMContextProvider;
import sonia.scm.util.IOUtil;
import sonia.scm.util.Util;

//~--- JDK imports ------------------------------------------------------------

import java.io.IOException;
import java.io.PrintWriter;

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

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Sebastian Sdorra
 */
@Singleton
public class ErrorServlet extends HttpServlet
{

  /** Field description */
  private static final long serialVersionUID = -3289076078469757874L;

  //~--- constructors ---------------------------------------------------------

  /**
   * Constructs ...
   *
   *
   * @param context
   * @param handler
   */
  @Inject
  public ErrorServlet(SCMContextProvider context, TemplateHandler handler)
  {
    this.context = context;
    this.handler = handler;
  }

  //~--- methods --------------------------------------------------------------

  /**
   * Method description
   *
   *
   * @param request
   * @param response
   *
   * @throws IOException
   * @throws ServletException
   */
  @Override
  protected void doGet(HttpServletRequest request, HttpServletResponse response)
          throws ServletException, IOException
  {
    processRequest(request, response);
  }

  /**
   * Method description
   *
   *
   * @param request
   * @param response
   *
   * @throws IOException
   * @throws ServletException
   */
  @Override
  protected void doPost(HttpServletRequest request,
                        HttpServletResponse response)
          throws ServletException, IOException
  {
    processRequest(request, response);
  }

  /**
   * Method description
   *
   *
   * @param request
   * @param response
   *
   * @throws IOException
   * @throws ServletException
   */
  private void processRequest(HttpServletRequest request,
                              HttpServletResponse response)
          throws ServletException, IOException
  {
    PrintWriter writer = null;

    try
    {
      writer = response.getWriter();

      Map<String, Object> env = new HashMap<String, Object>();
      String error = Util.EMPTY_STRING;

      if (context.getStartupError() != null)
      {
        error = Throwables.getStackTraceAsString(context.getStartupError());
      }

      env.put("error", error);
      handler.render("/error.html", writer, env);
    }
    finally
    {
      IOUtil.close(context);
    }
  }

  //~--- fields ---------------------------------------------------------------

  /** Field description */
  private SCMContextProvider context;

  /** Field description */
  private TemplateHandler handler;
}