Utf8EncodingFilter.java

/* vim: set ts=2 et sw=2 cindent fo=qroca: */

package com.globant.katari.core.web;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/** This filter sets the request encoding to UTF-8.
 *
 * It is vital that this is always the first filter in the chain to ensure that
 * the encoding is set before any <code>request.getParameter()</code> is
 * performed. The safest way is to put it as the first filter to execute.
 */
public final class Utf8EncodingFilter implements Filter {

  /** The class logger.
   */
  private static Logger log = LoggerFactory.getLogger(Utf8EncodingFilter.class);

  /** Initializes the filter. It currently does nothing.
   *
   * @param filterConfig The provided filter configuration.
   * @throws ServletException in case of error.
   */
  public void init(final FilterConfig filterConfig) throws ServletException {
    log.trace("Entering init");
    // Do nothing.
    log.trace("Leaving init");
  }

  /** {@inheritDoc}
  */
  public void doFilter(final ServletRequest request, final ServletResponse
      response, final FilterChain chain) throws IOException,
      ServletException {

    log.trace("Entering doFilter.");

    // TODO This is forcing UTF-8 encoding, we've got to see what happens if
    // the browser sends a different encoding.
    //if (servletRequest.getCharacterEncoding() == null) {
    request.setCharacterEncoding("UTF-8");
    //}

    chain.doFilter(request, response);

    log.trace("Leaving doFilter.");
  }

  /** Called by the container when the filter is about to be destroyed.
   *
   * This implementation is empty.
   */
  public void destroy() {
    log.trace("Entering destroy");
    // Do nothing.
    log.trace("Leaving destroy");
  }
}