/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.felix.webconsole.internal.filter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ResourceBundle;
import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import org.apache.felix.webconsole.VariableResolver;
import org.apache.felix.webconsole.WebConsoleUtil;
/**
* The <code>FilteringResponseWrapper</code> wraps the response to provide a
* filtering writer for HTML responses. The filtering writer filters the
* response such that any string of the form <code>${some text}</code> is
* replaced by a translation of the <i>some text</i> according to the
* <code>ResourceBundle</code> provided in the constructor. If no translation
* exists in the resource bundle, the text is written unmodifed (except the
* wrapping <code>${}</code> characters are removed.
*/
public class FilteringResponseWrapper extends HttpServletResponseWrapper
{
// the resource bundle providing translations for the output
private final ResourceBundle locale;
// the servlet request providing the variable resolver at the time
// the getWriter() method is called
private final ServletRequest request;
// the writer sending output in this response
private PrintWriter writer;
/**
* Creates a wrapper instance using the given resource bundle for
* translations.
*
* @param response the response to wrap
* @param locale a resource bundle, that will be used for translation of the strings
* @param request the original request - used to obtain the variable resolver
*/
public FilteringResponseWrapper( final HttpServletResponse response, final ResourceBundle locale,
final ServletRequest request )
{
super( response );
this.locale = locale;
this.request = request;
}
/**
* Returns a <code>PrintWriter</code> for the response. If <code>text/html</code>
* is being generated a filtering writer is returned which translates
* strings enclosed in <code>${}</code> according to the resource bundle
* configured for this response.
*
* @see javax.servlet.ServletResponseWrapper#getWriter()
*/
public PrintWriter getWriter() throws IOException
{
if ( writer == null )
{
final PrintWriter base = super.getWriter();
if ( doWrap() )
{
final VariableResolver resolver = WebConsoleUtil.getVariableResolver( request );
final ResourceFilteringWriter filter = new ResourceFilteringWriter( base, locale, resolver );
writer = new PrintWriter( filter );
}
else
{
writer = base;
}
}
return writer;
}
private final boolean doWrap()
{
boolean doWrap = getContentType() != null && getContentType().indexOf( "text/html" ) >= 0;
return doWrap;
}
}