rule.java

urlrewritefilter-2.6-src.zip

/**
 * Copyright (c) 2005, Paul Tuckey
 * All rights reserved.
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */
package org.tuckey.web.filters.urlrewrite;

import org.tuckey.web.filters.urlrewrite.utils.Log;
import org.tuckey.web.filters.urlrewrite.utils.StringUtils;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * Defines a rule that can be run against an incoming request.
 * 20040304 - Thanks to Scott Askew for help with concurrency issue with Perl5Compiler and Perl5Matcher
 *
 * @author Paul Tuckey
 * @version $Revision: 1.19 $ $Date: 2005/12/07 10:27:03 $
 */
public final class Rule extends RuleBase {

    private static Log log = Log.getLog(Rule.class);

    private short toType = TO_TYPE_FORWARD;  // default to passthrough/forward

    private static final short TO_TYPE_REDIRECT = 0;
    private static final short TO_TYPE_FORWARD = 1;
    private static final short TO_TYPE_PERMANENT_REDIRECT = 2;
    private static final short TO_TYPE_TEMPORARY_REDIRECT = 3;
    private static final short TO_TYPE_PRE_INCLUDE = 4;
    private static final short TO_TYPE_POST_INCLUDE = 5;

    private boolean encodeToUrl = false;

    /**
     * Constructor.
     */
    public Rule() {
        // empty
    }

    /**
     * Will run the rule against the uri and perform action required will return false is not matched
     * otherwise true.
     *
     * @param url
     * @param hsRequest
     * @return String of the rewritten url or the same as the url passed in if no match was made
     */
    public RewrittenUrl execute(final String url, final HttpServletRequest hsRequest,
                                final HttpServletResponse hsResponse)
            throws IOException, ServletException {
        RuleExecutionOutput ruleExecutionOutput = super.executeBase(url, hsRequest, hsResponse);
        if (ruleExecutionOutput == null || !ruleExecutionOutput.isRuleMatched()) {
            // no match, or run/set only match
            return null;
        }
        return rewriteRequest(ruleExecutionOutput);
    }


    /**
     * Will perform the action defined by the rule ie, redirect or passthrough.
     *
     * @param ruleExecutionOutput
     */
    private RewrittenUrl rewriteRequest(RuleExecutionOutput ruleExecutionOutput) {

        RewrittenUrl rewrittenRequest = new RewrittenUrl(ruleExecutionOutput);
        String toUrl = ruleExecutionOutput.getReplacedUrl();

        if (toType == TO_TYPE_REDIRECT) {
            if (log.isDebugEnabled()) {
                log.debug("needs to be redirected to " + toUrl);
            }
            rewrittenRequest.setRedirect(true);

        } else if (toType == TO_TYPE_PERMANENT_REDIRECT) {
            if (log.isDebugEnabled()) {
                log.debug("needs to be permanentely redirected to " + toUrl);
            }
            rewrittenRequest.setPermanentRedirect(true);

        } else if (toType == TO_TYPE_TEMPORARY_REDIRECT) {
            if (log.isDebugEnabled()) {
                log.debug("needs to be temporarily redirected to " + toUrl);
            }
            rewrittenRequest.setTemporaryRedirect(true);

        } else if (toType == TO_TYPE_PRE_INCLUDE) {
            if (log.isDebugEnabled()) {
                log.debug(toUrl + " needs to be pre included");
            }
            rewrittenRequest.setPreInclude(true);

        } else if (toType == TO_TYPE_POST_INCLUDE) {
            if (log.isDebugEnabled()) {
                log.debug(toUrl + " needs to be post included");
            }
            rewrittenRequest.setPostInclude(true);

        } else if (toType == TO_TYPE_FORWARD) {

            // pass the request to the "to" url
            if (log.isDebugEnabled()) {
                log.debug("needs to be forwarded to " + toUrl);
            }
            rewrittenRequest.setForward(true);
        }
        if (encodeToUrl) {
            rewrittenRequest.setEncode(true);
        } else {
            rewrittenRequest.setEncode(false);
        }

        return rewrittenRequest;
    }


    /**
     * Will initialise the rule.
     *
     * @return true on success
     */
    public boolean initialise(ServletContext context) {
        boolean ok = super.initialise(context);
        // check all the conditions
        initialised = true;
        if (!ok) {
            log.debug("failed to load rule");
        } else {
            log.debug("loaded rule " + getDisplayName() + " (" + from + ", " + to + " " + toType + ")");
        }
        if (errors.size() > 0) {
            ok = false;
        }
        valid = ok;
        return ok;
    }


    /**
     * Redirect or passthrough, passthrough is the default.
     *
     * @param toTypeStr to type string
     */
    public void setToType(final String toTypeStr) {
        if ("redirect".equals(toTypeStr)) {
            toType = TO_TYPE_REDIRECT;
        } else if ("permanent-redirect".equals(toTypeStr)) {
            toType = TO_TYPE_PERMANENT_REDIRECT;
        } else if ("temporary-redirect".equals(toTypeStr)) {
            toType = TO_TYPE_TEMPORARY_REDIRECT;
        } else if ("pre-include".equals(toTypeStr)) {
            toType = TO_TYPE_PRE_INCLUDE;
        } else if ("post-include".equals(toTypeStr)) {
            toType = TO_TYPE_POST_INCLUDE;
        } else if ("forward".equals(toTypeStr) || "passthrough".equals(toTypeStr) ||
                StringUtils.isBlank(toTypeStr)) {
            toType = TO_TYPE_FORWARD;
        } else {
            addError("type (" + toTypeStr + ") is not valid");
        }
    }

    /**
     * Will get to type ie redirect or passthrough.
     *
     * @return String
     */
    public String getToType() {
        if (toType == TO_TYPE_REDIRECT) return "redirect";
        if (toType == TO_TYPE_PERMANENT_REDIRECT) return "permanent-redirect";
        if (toType == TO_TYPE_TEMPORARY_REDIRECT) return "temporary-redirect";
        if (toType == TO_TYPE_PRE_INCLUDE) return "pre-include";
        if (toType == TO_TYPE_POST_INCLUDE) return "post-include";
        return "forward";
    }

    protected void addError(String s) {
        log.error("Rule " + getDisplayName() + " had error: " + s);
        super.addError(s);
    }

    public String getDisplayName() {
        if (name != null) {
            return name + " (rule " + id + ")";
        }
        return "Rule " + id;
    }

    public String getFullDisplayName() {
        return getDisplayName() + " (" + from + ", " + to + " " + toType + ")";
    }

    public boolean isEncodeToUrl() {
        return encodeToUrl;
    }

    public void setEncodeToUrl(boolean encodeToUrl) {
        this.encodeToUrl = encodeToUrl;
    }

}

class RuleExecutionOutput {
    private String replacedUrl;
    private boolean ruleMatched = false;
    private boolean stopFilterMatch = false;

    public RuleExecutionOutput(String replacedUrl, boolean ruleMatched) {
        this.replacedUrl = replacedUrl;
        this.ruleMatched = ruleMatched;
    }

    public String getReplacedUrl() {
        return replacedUrl;
    }

    public boolean isRuleMatched() {
        return ruleMatched;
    }

    public boolean isStopFilterMatch() {
        return stopFilterMatch;
    }

    public void setStopFilterMatch(boolean stopFilterMatch) {
        this.stopFilterMatch = stopFilterMatch;
    }

    public void setReplacedUrl(String replacedUrl) {
        this.replacedUrl = replacedUrl;
    }

}