Source Viewer : WEB-INF/classes/org/apache/click/examples/page/general/PageActionImage.java

package org.apache.click.examples.page.general;

import java.io.IOException;
import java.io.InputStream;
import javax.servlet.ServletContext;
import org.apache.click.Context;
import org.apache.click.ActionResult;
import org.apache.click.examples.page.BorderPage;
import org.apache.click.util.ClickUtils;
import org.apache.commons.io.IOUtils;

/**
 * This demo shows to invoke a PAGE_ACTION using an HTML <img> tag. The pageAction
 * will render the image data to the browser.
 */
public class PageActionImage extends BorderPage {

    private static final long serialVersionUID = 1L;

    /**
     * This page method is invoked from the <img> element and returns an ActionResult
     * instance containing the static image data.
     */
    public ActionResult getStaticImageData() {
        // Load the static image 'click-icon-blue-32.png'
        byte[] imageData = loadImageData("click-icon-blue-32.png");

        // Lookup the contentType for a PNG image
        String contentType = ClickUtils.getMimeType("png");

        // Return an ActionResult containing the image data
        return new ActionResult(imageData, contentType);
    }

    /**
     * This page method is invoked from the <img> element and returns an ActionResult
     * instance containing the image data specified by the imageName parameter.
     */
    public ActionResult getDynamicImageData() {
        Context context = getContext();

        // Retrieve the image name parameter from the request
        String imageName = context.getRequestParameter("imageName");

        // Load the static image 'click-icon-blue-32.png'
        byte[] imageData = loadImageData(imageName);

        // Lookup the contentType for a PNG image
        String contentType = ClickUtils.getMimeType("png");

        // Return an ActionResult containing the image data
        return new ActionResult(imageData, contentType);
    }

    private byte[] loadImageData(String imageName) {
        try {
            ServletContext servletContext = getContext().getServletContext();
            InputStream is = servletContext.getResourceAsStream("/assets/images/" + imageName);
            byte[] imageData = IOUtils.toByteArray(is);
            return imageData;

        } catch (IOException ioe) {
            throw new RuntimeException(ioe);
        }
    }
}