package com.atlassian.core.filters;
   
   import com.atlassian.core.filters.cache.CachingStrategy;
   import com.atlassian.core.filters.cache.JspCachingStrategy;
   import com.atlassian.core.filters.legacy.WordCurlyQuotesRequestWrapper;
   import com.atlassian.core.filters.legacy.NoContentLocationHeaderResponseWrapper;
   import com.atlassian.core.filters.encoding.FixedHtmlEncodingResponseWrapper;
   
   import javax.servlet.*;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.io.IOException;
  
  public abstract class AbstractEncodingFilter extends AbstractHttpFilter
  {
      private final CachingStrategy jspCachingStrategy = new JspCachingStrategy();
  
      public void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws IOException, ServletException
      {
          request.setCharacterEncoding(getEncoding());
          response.setContentType(getContentType());
  
          // prevent caching of JSPs
          if (isNonCachableUri(request))
              setNonCachingHeaders(response);
  
          filterChain.doFilter(
              new WordCurlyQuotesRequestWrapper(request, getEncoding()),
              new FixedHtmlEncodingResponseWrapper(new NoContentLocationHeaderResponseWrapper(response)));
      }
  
      protected void setNonCachingHeaders(HttpServletResponse response)
      {
          jspCachingStrategy.setCachingHeaders(response);
      }
  
      // override this method to prevent caching of other file types
      protected boolean isNonCachableUri(HttpServletRequest request)
      {
          return jspCachingStrategy.matches(request);
      }
  
      protected abstract String getEncoding();
  
      protected abstract String getContentType();
  
  }