PentahoAwareCharacterEncodingFilter.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 2007 - 2009 Pentaho Corporation.  All rights reserved.
 *
*/
package org.pentaho.platform.web.http.filters;

import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.platform.web.http.messages.Messages;

/**
 * Looks at the <code>context-param</code> named <code>encoding</code> in <code>web.xml</code> for its encoding
 * selection. If not found, falls back to method used by superclass. Finally, defaults to <code>UTF-8</code>.
 * @author mlowery
 */
public class PentahoAwareCharacterEncodingFilter extends SetCharacterEncodingFilter {

  // ~ Static fields/initializers ============================================

  private static final Log logger = LogFactory.getLog(PentahoAwareCharacterEncodingFilter.class);

  public static final String INIT_PARAM_ENCODING = "encoding"; //$NON-NLS-1$

  public static final String DEFAULT_CHAR_ENCODING = "UTF-8"; //$NON-NLS-1$

  // ~ Instance fields =======================================================

  // ~ Constructors ==========================================================

  public PentahoAwareCharacterEncodingFilter() {
    super();
  }

  // ~ Methods ===============================================================

  @Override
  protected String selectEncoding(final ServletRequest request) {
    if (request instanceof HttpServletRequest) {
      HttpServletRequest httpRequest = (HttpServletRequest) request;
      String enc = httpRequest.getSession(true).getServletContext().getInitParameter(PentahoAwareCharacterEncodingFilter.INIT_PARAM_ENCODING);
      if (StringUtils.isNotBlank(enc)) {
        if (PentahoAwareCharacterEncodingFilter.logger.isDebugEnabled()) {
          PentahoAwareCharacterEncodingFilter.logger.debug(Messages.getInstance().getString("PentahoAwareCharacterEncodingFilter.ENCODING_IN_CTX", enc)); //$NON-NLS-1$
        }
        return enc;
      }
    }
    String enc = super.selectEncoding(request);
    if (StringUtils.isNotBlank(enc)) {
      if (PentahoAwareCharacterEncodingFilter.logger.isDebugEnabled()) {
        PentahoAwareCharacterEncodingFilter.logger.debug(Messages.getInstance().getString("PentahoAwareCharacterEncodingFilter.ENCODING_IN_FILTER_INIT", enc)); //$NON-NLS-1$
      }
      return enc;
    } else {
      if (PentahoAwareCharacterEncodingFilter.logger.isWarnEnabled()) {
        PentahoAwareCharacterEncodingFilter.logger.warn(Messages.getInstance().getString("PentahoAwareCharacterEncodingFilter.COULD_NOT_FIND_ENCODING", //$NON-NLS-1$
            PentahoAwareCharacterEncodingFilter.DEFAULT_CHAR_ENCODING));
      }
      return PentahoAwareCharacterEncodingFilter.DEFAULT_CHAR_ENCODING;
    }
  }

}