com.mtgi.analytics.servlet.ServletRequestBehaviorTrackingAdapter.java Source code

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Here is the source code for com.mtgi.analytics.servlet.ServletRequestBehaviorTrackingAdapter.java

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/* 
 * Copyright 2008-2009 the original author or authors.
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations
 * under the License.
 */

package com.mtgi.analytics.servlet;

import java.util.Enumeration;
import java.util.regex.Pattern;

import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;

import org.springframework.util.StringUtils;

import com.mtgi.analytics.BehaviorEvent;
import com.mtgi.analytics.BehaviorTrackingManager;
import com.mtgi.analytics.EventDataElement;

/**
 * <p>Facilitates behavior tracking for servlet requests via calls to 
 * {@link #start(ServletRequest)} and {@link #stop(BehaviorEvent)}.  The relative
 * verbosity of event logging is configured in the {@link #ServletRequestBehaviorTrackingAdapter(String, BehaviorTrackingManager, String[], String[], Pattern[]) constructor}.</p>
 * 
 * <p>This class abstracts the details of tracking servlet requests, so that
 * it can be reused by delegation in both listeners and filters.</p>
 */
public class ServletRequestBehaviorTrackingAdapter {

    public static final String DEFAULT_EVENT_TYPE = "http-request";

    public static final String PARAMETERS_ELEMENT = "parameters";
    public static final String PARAM_ELEMENT = "param";
    public static final String VALUE_ELEMENT = "value";
    public static final String NAME_ATTRIBUTE = "name";

    private String eventType;
    private BehaviorTrackingManager manager;
    private String[] parameters;
    private String[] nameParameters;
    private Pattern[] uriPatterns;

    public ServletRequestBehaviorTrackingAdapter(String eventType, BehaviorTrackingManager manager,
            String[] parameters, String[] nameParameters, Pattern[] uriPatterns) {
        this.eventType = StringUtils.hasText(eventType) ? eventType : DEFAULT_EVENT_TYPE;
        this.manager = manager;
        this.parameters = parameters;
        this.nameParameters = nameParameters;
        this.uriPatterns = uriPatterns;
    }

    public BehaviorEvent start(ServletRequest request) {

        HttpServletRequest req = (HttpServletRequest) request;
        if (!match(req))
            return null;

        String eventName = getEventName(req);
        BehaviorEvent event = manager.createEvent(eventType, eventName);

        //log relevant request data and parameters to the event.
        EventDataElement data = event.addData();
        data.add("uri", req.getRequestURI());
        data.add("protocol", req.getProtocol());
        data.add("method", req.getMethod());
        data.add("remote-address", req.getRemoteAddr());
        data.add("remote-host", req.getRemoteHost());

        if (this.parameters != null) {
            EventDataElement parameters = data.addElement(PARAMETERS_ELEMENT);
            //include only configured parameters
            for (String name : this.parameters) {
                String[] values = request.getParameterValues(name);
                if (values != null)
                    addParameter(parameters, name, values);
            }
        } else {
            EventDataElement parameters = data.addElement(PARAMETERS_ELEMENT);
            //include all parameters
            for (Enumeration<?> params = request.getParameterNames(); params.hasMoreElements();) {
                String name = (String) params.nextElement();
                String[] values = request.getParameterValues(name);
                addParameter(parameters, name, values);
            }
        }

        manager.start(event);
        return event;
    }

    public void stop(BehaviorEvent event) {
        if (event != null) //event may be null if match() returned false at the start of the request.
            manager.stop(event);
    }

    protected String getEventName(HttpServletRequest request) {
        //use the request path as an event name, excluding proto, host, and query string.
        String eventName = request.getRequestURI();
        //optionally use important parameters as part of the event name
        if (nameParameters != null) {
            char sep = '?';
            StringBuffer buf = new StringBuffer(eventName);
            for (String name : this.nameParameters) {
                String[] values = request.getParameterValues(name);
                if (values != null) {
                    for (String v : values) {
                        buf.append(sep).append(name).append('=').append(v);
                        sep = '&';
                    }
                }
            }
            eventName = buf.toString();
        }

        return eventName;
    }

    protected boolean match(HttpServletRequest request) {
        if (uriPatterns == null)
            return true;
        for (Pattern p : uriPatterns)
            if (p.matcher(request.getRequestURI()).matches())
                return true;
        return false;
    }

    private static final void addParameter(EventDataElement parameters, String name, String[] values) {
        EventDataElement param = parameters.addElement(PARAM_ELEMENT);
        param.add(NAME_ATTRIBUTE, name);
        for (String v : values)
            param.addElement(VALUE_ELEMENT).setText(v);
    }

}