com.mindmutex.draugiem.filters.InnerFilterChain.java Source code

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Here is the source code for com.mindmutex.draugiem.filters.InnerFilterChain.java

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/**
 * Copyright (C) 2011 by mindmutex.com
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.mindmutex.draugiem.filters;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.slf4j.Logger;

/**
 * {@link FilterChain} implementation for {@link InnerFilter} instances.
 *
 * @author ivarsv
 */
public class InnerFilterChain implements FilterChain {

    /**
     * {@link Logger}.
     */
    private Log logger = LogFactory.getLog(getClass());

    /**
     * List of {@link InnerFilter} instances.
     */
    private List<InnerFilter> filters = new ArrayList<InnerFilter>();

    /**
     * This instance iterator.
     */
    private Iterator<InnerFilter> currentIterator = null;

    /**
     * Configuration properties.
     */
    private Properties configuration;

    /**
     * Creates default {@link InnerFilter} instances.
     *
     * @see AuthenticationFilter
     * @see AuthenticationTimeoutFilter
     * @see SessionToContextFilter
     *
     * @param configuration configuration
     * @return default filters
     */
    public static InnerFilterChain createDefault(Properties configuration) {
        InnerFilterChain chain = new InnerFilterChain(configuration);
        chain.addInnerFilter(new AuthenticationTimeoutFilter());
        chain.addInnerFilter(new AuthenticationFilter());
        chain.addInnerFilter(new SessionToContextFilter());

        return chain;
    }

    public InnerFilterChain(Properties configuration) {
        this.configuration = configuration;
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException {
        doFilter((HttpServletRequest) request, (HttpServletResponse) response);
    }

    /**
     * Initialised {@link #currentIterator} if not initialised and executes the next
     * filter in order.
     *
     * @param request HTTP request
     * @param response HTTP response
     *
     * @throws IOException when something goes wrong within filter
     * @throws ServletException when something goes wrong within filter
     */
    private void doFilter(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {

        if (currentIterator == null) {
            currentIterator = filters.iterator();
        }
        if (currentIterator.hasNext()) {
            InnerFilter filter = currentIterator.next();
            if (logger.isDebugEnabled()) {
                logger.debug("executing inner filter: " + filter.getClass().getName());
            }
            if (filter.init(configuration)) {
                filter.doFilter(request, response, this);
            }
        }
    }

    public void reset() {
        currentIterator = null;
    }

    public void addInnerFilter(InnerFilter filter) {
        filters.add(filter);
    }
}