org.apache.myfaces.custom.captcha.CAPTCHARenderer Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of tomahawk12 Show documentation
JSF components and utilities that can be used with any JSF implementation. This library is based on the JSF1.1 version of Tomahawk, but with minor source code and build changes to take advantage of JSF1.2 features. A JSF1.2 implementation is required to use this version of the Tomahawk library.
The newest version!
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.myfaces.custom.captcha;

import java.awt.Color;
import java.io.IOException;
import java.util.Map;

import javax.faces.FacesException;
import javax.faces.FactoryFinder;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.context.FacesContextFactory;
import javax.faces.context.ResponseStream;
import javax.faces.context.ResponseWriter;
import javax.faces.lifecycle.Lifecycle;
import javax.faces.lifecycle.LifecycleFactory;
import javax.faces.render.Renderer;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.myfaces.component.html.util.HtmlComponentUtils;
import org.apache.myfaces.component.html.util.ParameterResourceHandler;
import org.apache.myfaces.custom.captcha.util.CAPTCHAConstants;
import org.apache.myfaces.custom.captcha.util.CAPTCHAImageGenerator;
import org.apache.myfaces.custom.captcha.util.CAPTCHAResponseStream;
import org.apache.myfaces.custom.captcha.util.CAPTCHATextGenerator;
import org.apache.myfaces.custom.captcha.util.ColorGenerator;
import org.apache.myfaces.renderkit.html.util.AddResource;
import org.apache.myfaces.renderkit.html.util.AddResourceFactory;
import org.apache.myfaces.renderkit.html.util.ResourceLoader;

import org.apache.myfaces.shared_tomahawk.renderkit.html.HTML;
import org.apache.myfaces.tomahawk.config.TomahawkConfig;

/**
 *
 * @JSFRenderer
 *   renderKitId = "HTML_BASIC"
 *   family = "org.apache.myfaces.CAPTCHA"
 *   type = "org.apache.myfaces.CAPTCHA"
 * @since 1.1.7
 * @author Hazem Saleh
 *
 */
public class CAPTCHARenderer extends Renderer implements ResourceLoader
{

    public void encodeBegin(FacesContext context, UIComponent component)
            throws IOException
    {

        CAPTCHAComponent captchaComponent = (CAPTCHAComponent) component;

        generateImageTag(context, captchaComponent);
    }

    public void encodeEnd(FacesContext context, UIComponent component)
            throws IOException
    {
        super.encodeEnd(context, component);
    }

    /*
     * This helper method is used for generating the img tag that will
     * use the (AddResource) to generate the url of the generated image.
     */
    private void generateImageTag(FacesContext context,
            CAPTCHAComponent component) throws IOException
    {

        AddResource addResource;
        ResponseWriter writer = context.getResponseWriter();
        Map params = HtmlComponentUtils.getParameterMap(component);
        String url;
        String captchaSessionKeyName = component.getCaptchaSessionKeyName();
        String width = component.getImageWidth();
        String height = component.getImageHeight();

        // determine width and height of the generated image.
        if (width == null)
        {
            width = CAPTCHAConstants.DEFAULT_CAPTCHA_WIDTH + "";
        }

        if (height == null)
        {
            height = CAPTCHAConstants.DEFAULT_CAPTCHA_HEIGHT + "";
        }

        writer.startElement(HTML.IMG_ELEM, component);

        // constructing the parameter map to be passed to the (AddResource).
        if (captchaSessionKeyName != null)
        {
            params.put(CAPTCHAComponent.ATTRIBUTE_CAPTCHA_SESSION_KEY_NAME,
                    captchaSessionKeyName);
        }

        // write the url to trigger the (AddResource).
        addResource = AddResourceFactory.getInstance(context);

        url = context.getExternalContext().encodeResourceURL(
                addResource.getResourceUri(context,
                        new ParameterResourceHandler(this.getClass(), params)));

        // adding dummy parameter to prevent caching.
        writer.writeAttribute(HTML.SRC_ATTR, url + "&dummyParameter="
                + System.currentTimeMillis(), null);

        // write rest of attributes.
        writer.writeAttribute(HTML.WIDTH_ATTR, width, null);

        writer.writeAttribute(HTML.HEIGHT_ATTR, height, null);

        writer.endElement(HTML.IMG_ELEM);
    }

    /*
     * This method is implemented to be called from the (AddResource).
     * It wraps the CAPTCHA image generation.
     */
    public void serveResource(ServletContext servletContext,
            HttpServletRequest request, HttpServletResponse response,
            String resourceUri) throws IOException
    {

        // get the FacesContext from the ServletContext.
        FacesContextFactory facesContextFactory = (FacesContextFactory) FactoryFinder
                .getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);
        LifecycleFactory lifecycleFactory = (LifecycleFactory) FactoryFinder
                .getFactory(FactoryFinder.LIFECYCLE_FACTORY);
        Lifecycle lifecycle = lifecycleFactory.getLifecycle(HtmlComponentUtils
                .getLifecycleId(servletContext));
        FacesContext facesContext = facesContextFactory.getFacesContext(
                servletContext, request, response, lifecycle);
        facesContext.setResponseStream(new CAPTCHAResponseStream(response
                .getOutputStream()));

        // render the CAPTCHA.
        try
        {
            try
            {
                renderCAPTCHA(facesContext);
            }
            catch (IOException e)
            {
                throw new FacesException("Could not render the CAPTCHA : "
                        + e.getMessage(), e);
            }
            facesContext.getResponseStream().close();
        }
        finally
        {
            facesContext.release();
        }
    }

    /*
     * This method is used for rendering the CAPTCHA component.
     */
    protected void renderCAPTCHA(FacesContext facesContext) throws IOException
    {

        // getting CAPTCHA attributes.
        HttpServletResponse response = (HttpServletResponse) facesContext
                .getExternalContext().getResponse();
        ResponseStream out = facesContext.getResponseStream();
        Map requestMap = facesContext.getExternalContext()
                .getRequestParameterMap();
        String captchaSessionKeyName = requestMap.get(
                CAPTCHAComponent.ATTRIBUTE_CAPTCHA_SESSION_KEY_NAME).toString();

        // construct the CAPTCHA image generator object.
        CAPTCHAImageGenerator captchaImageGenerator = new CAPTCHAImageGenerator();

        try
        {
            String captchaText;
            Color endingColor = ColorGenerator.generateRandomColor(null);
            Color startingColor = ColorGenerator
                    .generateRandomColor(endingColor);

            // Generate random CAPTCHA text.
            captchaText = CAPTCHATextGenerator.generateRandomText();

            TomahawkConfig config = TomahawkConfig.getCurrentInstance(facesContext);
            // Set the generated text in the user session.
            facesContext.getExternalContext().getSessionMap().put(
                    config.isPrefixCaptchaSessionKey() ? 
                    AbstractCAPTCHAComponent.ATTRIBUTE_CAPTCHA_SESSION_KEY_NAME+
                    "_"+captchaSessionKeyName : captchaSessionKeyName, captchaText);

            // Generate the image, the BG color is randomized from starting to ending colors.
            captchaImageGenerator.generateImage(response, captchaText,
                    startingColor, endingColor);
        }
        finally
        {
            out.close();
            facesContext.responseComplete();
        }
    }
}