SystemStatusFilter.java

/*
 * This program is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software 
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this 
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html 
 * or from the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * 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 Lesser General Public License for more details.
 *
 * Copyright 2006 - 2009 Pentaho Corporation.  All rights reserved.
 *
 *
 * @created August, 2006
 * @author Marc Batchelor
 * 
 */
package org.pentaho.platform.web.http.filters;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.pentaho.platform.engine.core.system.PentahoSystem;

/**
 * The purpose of this filter is to check to make sure that the platform is
 * properly initialized before letting requests in.
 *
 */
public class SystemStatusFilter implements Filter {

  private String redirectToOnInitError;

  private boolean systemInitializedOk;

  public void init(final FilterConfig filterConfig) throws ServletException {
    String failurePage = filterConfig.getInitParameter("initFailurePage"); //$NON-NLS-1$
    if ((failurePage == null) || (failurePage.length() == 0)) {
      failurePage = "InitFailure"; //$NON-NLS-1$
    }
    redirectToOnInitError = "/" + failurePage; //$NON-NLS-1$ 
    systemInitializedOk = PentahoSystem.getInitializedOK();
  }

  public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain filterChain) throws IOException,
      ServletException {
    if (systemInitializedOk) {
      filterChain.doFilter(request, response);
    } else {
      HttpServletRequest req = (HttpServletRequest) request;
      if (req.getServletPath().endsWith(redirectToOnInitError)) {
        filterChain.doFilter(request, response);
      } else {
        RequestDispatcher dispatcher = request.getRequestDispatcher(redirectToOnInitError);
        dispatcher.forward(request, response);
      }
    }
  }

  public void destroy() {
  }

}