it.geosolutions.httpproxy.callback.RequestTypeChecker.java Source code

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Here is the source code for it.geosolutions.httpproxy.callback.RequestTypeChecker.java

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/*
 *  Copyright (C) 2007 - 2011 GeoSolutions S.A.S.
 *  http://www.geo-solutions.it
 *
 *  GPLv3 + Classpath exception
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package it.geosolutions.httpproxy.callback;

import it.geosolutions.httpproxy.exception.HttpErrorException;
import it.geosolutions.httpproxy.service.ProxyConfig;

import java.io.IOException;
import java.net.URL;
import java.util.HashSet;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.httpclient.HttpMethod;

/**
 * RequestTypeChecker class for request type check.
 * 
 * @author Tobia Di Pisa at tobia.dipisa@geo-solutions.it
 * @author Alejandro Diaz
 */
public class RequestTypeChecker extends AbstractProxyCallback implements ProxyCallback {

    /**
     * Compiled patterns
     */
    private Set<Pattern> patterns;

    /**
     * Last request types
     */
    private Set<String> lastReqTypes;

    /**
     * Default constructor
     */
    public RequestTypeChecker() {
        super();
    }

    /**
     * @param config
     */
    public RequestTypeChecker(ProxyConfig config) {
        super(config);
        loadPatterns();
    }

    /**
     * Patterns set initializer
     */
    private void loadPatterns() {
        Set<String> reqTypes = config.getReqtypeWhitelist();
        // Check if lastRequestTypes has changed
        if (hasChanged(reqTypes)) {
            patterns = new HashSet<Pattern>();
            if (reqTypes != null && reqTypes.size() > 0) {
                for (String regex : reqTypes) {
                    patterns.add(Pattern.compile(regex));
                }
            }
        }
    }

    /**
     * Auxiliary method to check if the reqType set has been changed
     * 
     * @param reqTypes
     *            new set of request types
     * 
     * @return true if the request type parameters has been changed or false
     *         otherwise
     */
    private boolean hasChanged(Set<String> reqTypes) {

        boolean changed = false;

        if (lastReqTypes == null) {
            // Not compiled yet!
            changed = true;
        } else {

            for (String reqType : reqTypes) {
                if (!lastReqTypes.contains(reqType)) {
                    // it's a new request type --> we must recompile
                    changed = true;
                    break;
                } else {
                    lastReqTypes.remove(reqType);
                }
            }

            // if request types hasn't changed, the set must be empty
            changed = changed || !lastReqTypes.isEmpty();
        }

        // Save the new last request types and return the ''change'' value
        lastReqTypes = reqTypes;
        return changed;
    }

    /*
      * (non-Javadoc)
      * 
      * @see it.geosolutions.httpproxy.ProxyCallback#onRequest(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
      */
    public void onRequest(HttpServletRequest request, HttpServletResponse response, URL url) throws IOException {
        loadPatterns();

        // //////////////////////////////////////
        // Check off the request type
        // provided vs. permitted request types
        // //////////////////////////////////////

        String urlExtForm = url.toExternalForm();

        boolean check = false;
        for (Pattern pattern : patterns) {
            Matcher matcher = pattern.matcher(urlExtForm);

            if (matcher.matches()) {
                check = true;
                break;
            }
        }

        if (!check)
            throw new HttpErrorException(403, "Request Type" + " is not among the ones allowed for this proxy");
    }

    /*
     * (non-Javadoc)
     * 
     * @see it.geosolutions.httpproxy.ProxyCallback#onRemoteResponse(org.apache.commons.httpclient.HttpMethod)
     */
    public void onRemoteResponse(HttpMethod method) throws IOException {
    }

    /*
     * (non-Javadoc)
     * 
     * @see it.geosolutions.httpproxy.ProxyCallback#onFinish()
     */
    public void onFinish() throws IOException {
    }

}