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package com.vaadin.tests.minitutorials.v7a1;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import com.vaadin.server.ExternalResource;
import com.vaadin.server.RequestHandler;
import com.vaadin.server.Resource;
import com.vaadin.server.VaadinRequest;
import com.vaadin.tests.components.AbstractReindeerTestUI;
import com.vaadin.ui.Image;
public class DynamicImageUI extends AbstractReindeerTestUI {
public static final String IMAGE_URL = "myimage.png";
private final RequestHandler requestHandler = (session, request,
response) -> {
if (("/" + IMAGE_URL).equals(request.getPathInfo())) {
// Create an image, draw the "text" parameter to it and output
// it to the browser.
String text = request.getParameter("text");
BufferedImage bi = new BufferedImage(100, 30,
BufferedImage.TYPE_3BYTE_BGR);
bi.getGraphics().drawChars(text.toCharArray(), 0, text.length(), 10,
20);
response.setContentType("image/png");
ImageIO.write(bi, "png", response.getOutputStream());
return true;
}
// If the URL did not match our image URL, let the other request
// handlers handle it
return false;
};
@Override
public void setup(VaadinRequest request) {
Resource resource = new ExternalResource(IMAGE_URL + "?text=Hello!");
getSession().addRequestHandler(requestHandler);
// Add an image using the resource
Image image = new Image("A dynamically generated image", resource);
addComponent(image);
}
@Override
public void detach() {
super.detach();
// Clean up
getSession().removeRequestHandler(requestHandler);
}
@Override
protected String getTestDescription() {
return "Mini tutorial for https://vaadin.com/wiki/-/wiki/Main/Generating%20dynamic%20resources%20based%20on%20URI%20or%20parameters";
}
@Override
protected Integer getTicketNumber() {
return null;
}
}
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