resourcetestpage.java

Wicket一个开发Java Web应用程序框架。它使得开发web应用程序变得容易而轻松。 Wicket利用一个POJO data beans组件使得它可以与任何持久层技术相结合。

/*
 * 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.wicket.threadtest.apps.app1;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.List;
import java.util.Locale;
import java.util.Random;

import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.markup.html.WebPage;
import org.apache.wicket.markup.html.WebResource;
import org.apache.wicket.markup.html.image.Image;
import org.apache.wicket.markup.html.list.ListItem;
import org.apache.wicket.markup.html.list.ListView;
import org.apache.wicket.util.resource.IResourceStream;
import org.apache.wicket.util.resource.ResourceStreamNotFoundException;
import org.apache.wicket.util.time.Time;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

/**
 * Web page with 50 dynamically-created image resources.
 * 
 * @author almaw
 */
public class ResourceTestPage extends WebPage
{

	public static final int IMAGES_PER_PAGE = 20;

	public ResourceTestPage()
	{
		List list = Arrays.asList(new Object[IMAGES_PER_PAGE]);
		add(new ListView("listView", list)
		{

			@Override
			protected void populateItem(ListItem item)
			{
				final Random random = new Random();
				BufferedImage image = new BufferedImage(16, 16, BufferedImage.TYPE_INT_RGB);
				Graphics gfx = image.getGraphics();
				gfx.setColor(new Color(random.nextFloat(), random.nextFloat(), random.nextFloat()));
				gfx.fillRect(0, 0, 32, 32);
				gfx.dispose();

				// Write it into a byte array as a JPEG.
				ByteArrayOutputStream baos = new ByteArrayOutputStream();
				JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(baos);
				try
				{
					encoder.encode(image);
				}
				catch (IOException e)
				{
					throw new WicketRuntimeException(e);
				}
				final byte[] imageData = baos.toByteArray();

				item.add(new Image("image", new WebResource()
				{

					@Override
					public IResourceStream getResourceStream()
					{
						return new IResourceStream()
						{

							public Time lastModifiedTime()
							{
								return Time.now();
							}

							public void setLocale(Locale locale)
							{
							}

							public long length()
							{
								return imageData.length;
							}

							public Locale getLocale()
							{
								return null;
							}

							// Make a 16x16 randomly background-coloured JPEG.
							public InputStream getInputStream()
									throws ResourceStreamNotFoundException
							{
								return new ByteArrayInputStream(imageData);
							}

							public String getContentType()
							{
								return "image/jpeg";
							}

							public void close() throws IOException
							{
							}

						};
					}

				}));
			}

		});
	}
}