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

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/*
 * 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;
/**
 * 
 * @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)));

    
    writer.writeAttribute(HTML.SRC_ATTR, url, 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();
    HttpServletRequest request = (HttpServletRequest) facesContext
        .getExternalContext().getRequest();
    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();        
        
        // Generate the image, the BG color is randomized from starting to ending colors.
            captchaImageGenerator.generateImage(response, captchaText,
            startingColor, endingColor);

        // Set the generated text in the user session.
        request.getSession().setAttribute(captchaSessionKeyName,
            captchaText);

    }
    finally 
    {
        out.close();
        facesContext.responseComplete();
    }
    }
}