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/*
* Copyright 2012 Vaadin Ltd.
*
* Licensed 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 com.vaadin.tests.minitutorials.v7b6;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.imageio.ImageIO;
import com.vaadin.server.FileDownloader;
import com.vaadin.server.StreamResource;
import com.vaadin.server.StreamResource.StreamSource;
import com.vaadin.server.VaadinRequest;
import com.vaadin.ui.Button;
import com.vaadin.ui.UI;
public class LettingUserDownloadFile extends UI {
@Override
protected void init(VaadinRequest request) {
Button downloadButton = new Button("Download image");
StreamResource myResource = createResource();
FileDownloader fileDownloader = new FileDownloader(myResource);
fileDownloader.extend(downloadButton);
setContent(downloadButton);
}
private StreamResource createResource() {
return new StreamResource(new StreamSource() {
@Override
public InputStream getStream() {
String text = "My image";
BufferedImage bi = new BufferedImage(100, 30,
BufferedImage.TYPE_3BYTE_BGR);
bi.getGraphics().drawChars(text.toCharArray(), 0,
text.length(), 10, 20);
try {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
ImageIO.write(bi, "png", bos);
return new ByteArrayInputStream(bos.toByteArray());
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
}, "myImage.png");
}
}
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