package com.cognifide.slice.core.internal.filter;
/*
* #%L
* Slice - Core
* $Id:$
* $HeadURL:$
* %%
* Copyright (C) 2012 Cognifide Limited
* %%
* Licensed 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.
* #L%
*/
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.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Properties;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Service;
import org.osgi.framework.Constants;
import com.cognifide.slice.api.context.Context;
import com.cognifide.slice.api.context.ContextProvider;
import com.cognifide.slice.core.internal.context.SliceContextFactory;
// @formatter:off
/**
* @author Witold Szczerba
* @author Rafał Malinowski
* @class ContextRequstFilter
*
* This filter is run for on each request. Each time it stores a Context instance with ServletRequest and
* ServletResponse values in per-thread variable. This Context is later accessible by getContext() and can be
* used in Injector instances that are used during this request.
*/
@Component(immediate = true)
@Service
@Properties({
@Property(name = Constants.SERVICE_DESCRIPTION, value = "Filter that is injected into request chain to provide access to request, resource and response."),
@Property(name = Constants.SERVICE_VENDOR, value = "Cognifide"),
@Property(name = Constants.SERVICE_RANKING, intValue = ContextRequstFilter.RANKING),
@Property(name = "filter.scope", value = {"request","forward"}) })
// @formatter:on
public class ContextRequstFilter implements Filter, ContextProvider {
public static final int RANKING = -800;
private final ThreadLocal<Context> contexts = new ThreadLocal<Context>();
@Override
public void init(final FilterConfig filterConfig) throws ServletException {
}
/**
* Update Context instance for current thread to use current request and response values.
*/
@Override
public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain)
throws IOException, ServletException {
final Context previous = contexts.get();
try {
final Context context = (new SliceContextFactory()).getServletRequestContext(request, response);
contexts.set(context);
chain.doFilter(request, response);
} finally {
contexts.set(previous);
}
}
@Override
public void destroy() {
}
/**
* @returns Context instance for current thread
*
* Return Context instance for current thread. It contains most current ServletRequest and ServletResponse
* instances.
*/
@Override
public Context getContext() {
return contexts.get();
}
}