WebImage.java

package czd.lib.view.smartimageview;

import android.content.Context;
import android.graphics.Bitmap;
import czd.lib.cache.BitmapCache;
import czd.lib.view.smartimageview.SmartImageTask.OnCompleteHandler;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class WebImage implements SmartImage {
	private String url;
	private boolean cancel=false;

	public WebImage(String url) {
		this.url = url.replaceAll(" ", "%20");
	}

	@Override
	public Bitmap getBitmap(Context context, OnCompleteHandler handler) {

		Bitmap bitmap = null;
		if (!cancel && url != null)
		{
			bitmap = BitmapCache.getInstance().get(url);
			if (bitmap == null || bitmap.isRecycled())
			{
				if (getImageFromUrl(url, handler))
				{
					bitmap = BitmapCache.getInstance().get(url);
				}
			}
		}
		return bitmap;
	}

	public Bitmap getBitmap(Context context, int width, int height, OnCompleteHandler handler) {

		Bitmap bitmap = null;
		if (!cancel && url != null)
		{
			bitmap = BitmapCache.getInstance().get(url);
			if (bitmap == null || bitmap.isRecycled())
			{
				if (getImageFromUrl(url, handler))
				{
					bitmap = BitmapCache.getInstance().get(url);
				}
			}
		}
		return bitmap;
	}

	public void cancel(){
		this.cancel=true;
		Thread.currentThread().interrupt();
	}
	
	@Override
	public String toString() {
		return url;
	}

	public static void removeFromCache(String url) {
		BitmapCache.getInstance().delete(url);
	}

	private void sendProgressMessage(OnCompleteHandler handler, long current, long total) {
		handler.sendMessage(handler.obtainMessage(SmartImageTask.MSG_PROGRESS, new Object[]{current, total}));
	}

	private boolean getImageFromUrl(String url, OnCompleteHandler handler) {
		if (cancel)
			return false;
		String filepath = BitmapCache.getInstance().getRealName(url);
		String tmp_filepath=filepath+".tmp";
		InputStream is = null;
		FileOutputStream os = null;
		try
		{
			File file = new File(tmp_filepath);
			boolean append;
			long current = 0;
			long total = 0;
			if (!file.exists() && file.getParentFile().canWrite())
			{
				if (!file.createNewFile())
					return false;
				append = false;
			}
			else if (!file.canWrite())
			{
				return false;
			}
			else
			{
				append = true;
				current = file.length();
			}
			HttpURLConnection conn = (HttpURLConnection)new URL(url).openConnection();
			conn.setConnectTimeout(3000);
			conn.setUseCaches(true);
			conn.setInstanceFollowRedirects(true);
			if (current > 0)
				conn.setRequestProperty("RANGE", "bytes=" + current + "-");

			if (cancel)
				return false;
			int code = conn.getResponseCode();
			if (code == 416)
			{
				sendProgressMessage(handler, current, current);
				file.renameTo(new File(filepath));
				return true;
			}
			else if (code > 300)
				return false;
			else
			{
				String header = conn.getHeaderField("Content-Range");
				if (header == null || header.length() == 0)
				{
					append = false;
					current = 0;
				}

				os = new FileOutputStream(file, append);
				is = conn.getInputStream();
				total = conn.getContentLength() + current;
				int k = 0;
				byte[] buffer = new byte[4096];
				while (!cancel && !Thread.currentThread().isInterrupted() && current < total && (k = is.read(buffer, 0, 4096)) > 0)
				{
					os.write(buffer, 0, k);
					current += k;
					sendProgressMessage(handler, current, total);
				}
				os.flush();
				if(!cancel && !Thread.currentThread().isInterrupted())
					file.renameTo(new File(filepath));
				return !cancel;
			}
		} catch (Exception e)
		{
			e.printStackTrace();
		} finally
		{
			try
			{
				if (is != null)
					is.close();
				if (os != null)
					os.close();
			} catch (IOException e)
			{
				e.printStackTrace();
			}
		}
		return false;
	}

}