albumpane.java

基于Ajax的WebOS————PhoneShow案例

package com.cownew.phoneshow.ent;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.UUID;

import nextapp.echo2.app.Button;
import nextapp.echo2.app.Grid;
import nextapp.echo2.app.ResourceImageReference;
import nextapp.echo2.app.Row;
import nextapp.echo2.app.WindowPane;
import nextapp.echo2.app.event.ActionEvent;
import nextapp.echo2.app.event.ActionListener;
import nextapp.echo2.app.filetransfer.Download;
import nextapp.echo2.app.filetransfer.UploadEvent;

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils;

import com.cownew.phoneshow.MainApp;
import com.cownew.phoneshow.framework.common.Resources;
import com.cownew.phoneshow.framework.common.ZipDownloadProvider;
import com.cownew.phoneshow.framework.ctrl.OpenFileDialog;
import com.cownew.phoneshow.framework.ctrl.UploadListenerAdapter;

import echopointng.ImageIcon;
import echopointng.PushButton;

public class AlbumPane extends WindowPane
{
	// 相册的包路径
	private String albumPath = "/album/" + MainApp.getActiveUserId() + "/";

	// 相册的路径
	// 为了避免多用户混淆，这里用用户id做包名
	private String uploadImgPath = "./writable/" + albumPath;

	private ImageIcon imgIcon;

	private File[] files;

	// 当前显示图片的索引号
	private int curIndex;

	public AlbumPane()
	{
		super();
		setTitle("在线相册");
		// 创建文件列表
		createFiles();

		// 创建布置界面的网格，只有一列
		Grid grid = new Grid(1);
		add(grid);

		// 由于有两个组件(前进后退)，所以首先将两个组件放到一个Row中，保证在一行中显示
		Row rowNavigator = new Row();
		Button btnPrev = new Button(Resources.ICON_24_LEFT_ARROW);
		btnPrev.addActionListener(new ActionListener() {

			public void actionPerformed(ActionEvent e)
			{
				prev();
			}
		});
		Button btnNext = new Button(Resources.ICON_24_RIGHT_ARROW);
		btnNext.addActionListener(new ActionListener() {

			public void actionPerformed(ActionEvent e)
			{
				next();
			}
		});
		rowNavigator.add(btnPrev);
		rowNavigator.add(btnNext);
		grid.add(rowNavigator);

		Row rowUpload = new Row();
		grid.add(rowUpload);

		PushButton btnUpload = new PushButton("上传");
		rowUpload.add(btnUpload);
		btnUpload.addActionListener(new ActionListener() {

			public void actionPerformed(ActionEvent e)
			{
				upload();
			}
		});

		PushButton btnDownload = new PushButton("打包下载");
		rowUpload.add(btnDownload);
		btnDownload.addActionListener(new ActionListener() {

			public void actionPerformed(ActionEvent e)
			{
				download();
			}
		});

		imgIcon = new ImageIcon();
		// 将图片加到表格中
		grid.add(imgIcon);
		next();
	}

	private void createFiles()
	{
		File rootFile = new File(uploadImgPath);
		// 如果目录不存在，则创建一个
		// 因为用户第一次进入的时候是没有这个目录的
		if (!rootFile.exists())
		{
			rootFile.mkdir();
		}
		files = rootFile.listFiles();
		curIndex = -1;
	}

	private void download()
	{
		// 文件打包下载
		Download download = new Download();
		download.setProvider(new ZipDownloadProvider(files, "album.zip"));
		MainApp.getActive().enqueueCommand(download);
	}

	private void upload()
	{
		OpenFileDialog openDlg = new OpenFileDialog(
				new UploadListenerAdapter() {

					public void fileUpload(UploadEvent e)
					{
						if (e.getContentType().startsWith("image/"))
						{
							saveUploadedImage(e);
							// 文件上传以后刷新列表
							createFiles();
						} else
						{
							// 限制只能上传图片类型的文件
							MainApp.showInfo("只能上传图片类型文件！");
						}
					}

				});
		MainApp.addComponent(openDlg);
	}

	// 显示下一张图片
	private void next()
	{
		if (curIndex < files.length - 1)
		{
			curIndex++;
		}
		if (curIndex >= 0)
		{
			File file = files[curIndex];
			imgIcon.setIcon(new ResourceImageReference(albumPath
					+ file.getName()));
		}
	}

	// 显示上一张图片
	private void prev()
	{
		if (curIndex > 0)
		{
			curIndex--;
		}
		if (curIndex >= 0)
		{
			File file = files[curIndex];
			imgIcon.setIcon(new ResourceImageReference(albumPath
					+ file.getName()));
		}
	}

	// 将上传的文件保存到本地
	private void saveUploadedImage(UploadEvent e)
	{
		// 调用commons-io包中的FilenameUtils工具类得到文件的扩展名
		String ext = FilenameUtils.getExtension(e.getFileName());

		FileOutputStream fos = null;
		InputStream inStream = e.getInputStream();
		try
		{
			// 创建以ext为扩展名的新文件名
			File file = createImageFile(ext);
			fos = new FileOutputStream(file);
			byte[] buff = new byte[1024];
			int iCount;
			while ((iCount = inStream.read(buff)) > 0)
			{
				fos.write(buff, 0, iCount);
			}
		} catch (FileNotFoundException fnfe)
		{
			MainApp.showInfo(fnfe.getMessage());
		} catch (IOException ioe)
		{
			MainApp.showInfo(ioe.getMessage());
		} finally
		{
			IOUtils.closeQuietly(fos);
			IOUtils.closeQuietly(inStream);
		}
	}

	/**
	 * 得到一个以ext为后缀的文件对象
	 * 
	 * @param ext
	 * @return
	 */
	private File createImageFile(String ext)
	{
		String uuid = UUID.randomUUID().toString();
		File file = new File(uploadImgPath + uuid + "." + ext);
		return file;
	}
}