src/org/jsecurity/web/servlet/FilterChainWrapper.java

/*
 * Copyright 2005-2008 Les Hazlewood
 *
 * 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.
 */
package org.jsecurity.web.servlet;

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

import javax.servlet.*;
import java.io.IOException;
import java.util.List;

/**
 * @author Les Hazlewood
 * @since 0.9
 */
public class FilterChainWrapper implements FilterChain {

    protected transient final Log log = LogFactory.getLog(getClass());

    private FilterChain orig;
    private List<Filter> filters;
    private int index = 0;

    public FilterChainWrapper( FilterChain orig, List<Filter> filters ) {
        this.orig = orig;
        this.filters = filters;
        this.index = 0;
    }

    public void doFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException {
        if ( this.filters == null || this.filters.size() == this.index ) {
            //we've reached the end of the wrapped chain, so invoke the original one:
            if ( log.isTraceEnabled() ) {
                log.trace( "Invoking original filter chain." );
            }
            this.orig.doFilter( request, response );
        } else {
            if ( log.isTraceEnabled() ) {
                log.trace( "Invoking wrapped filter at index [" + this.index + "]" );
            }
            this.filters.get(this.index++).doFilter(request,response,this);
        }
    }
}