AsyncImageLoader.java

package com.photoshare.utils.async;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.lang.ref.SoftReference;
import java.net.HttpURLConnection;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.Executor;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.Log;

import com.photoshare.service.photos.EditPhotoType;
import com.photoshare.utils.Utils;

public class AsyncImageLoader {

	private Map<String, SoftReference<Drawable>> imageCache = new HashMap<String, SoftReference<Drawable>>();

	public void loadImageFromFileUrl(final Executor pool,
			final String imageUrl, final ImageCallback mCallback) {

		Drawable drawable = get(imageUrl);

		if (drawable != null) {
			mCallback.imageLoaded(drawable, imageUrl);
			return;
		}

		pool.execute(new Runnable() {

			public void run() {
				// TODO Auto-generated method stub
				Bitmap bit = null;
				BitmapFactory.Options opt = new BitmapFactory.Options();
				opt.inPreferredConfig = Bitmap.Config.RGB_565;
				opt.inPurgeable = true;
				opt.inInputShareable = true;

				bit = BitmapFactory.decodeFile(imageUrl);
				Drawable drawable = new BitmapDrawable(bit);
				imageCache.put(imageUrl, new SoftReference<Drawable>(drawable));
				mCallback.imageLoaded(drawable, imageUrl);
			}

		});
	}

	public void loadImageFromWebUrl(final Executor pool, final String imageUrl,
			final ImageCallback mCallback) {

		Drawable drawable = get(imageUrl);

		if (drawable != null) {
			mCallback.imageLoaded(drawable, imageUrl);
			return;
		}

		pool.execute(new Runnable() {

			public void run() {
				// TODO Auto-generated method stub
				Bitmap bit = null;
				try {
					bit = getBitMapFromWeb(imageUrl);
				} catch (RuntimeException re) {
					mCallback.imageDefault();
				}
				Drawable drawable = new BitmapDrawable(bit);
				imageCache.put(imageUrl, new SoftReference<Drawable>(drawable));
				mCallback.imageLoaded(drawable, imageUrl);
			}

		});
	}

	public void docorateImage(final Executor pool, final EditPhotoType type,
			final Bitmap raw, final ImageCallback mCallback) {
		pool.execute(new Runnable() {

			public void run() {
				// TODO Auto-generated method stub
				Bitmap photo = type.Decorate(raw);
				if (mCallback != null) {
					BitmapDrawable drawable = new BitmapDrawable(photo);
					mCallback.imageLoaded(drawable, null);
				}
			}
		});
	}

	private Drawable get(final String imageUrl) {
		if (imageCache.containsKey(imageUrl)) {
			SoftReference<Drawable> softReference = imageCache.get(imageUrl);
			if (softReference.get() != null) {
				return softReference.get();
			}
		}
		return null;
	}

	private Bitmap getBitMapFromWeb(String path) throws RuntimeException {
		if (path == null) {
			
		}
		try {
			byte[] bytes = getBytes(path, null);
			Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0,
					bytes.length);
			return bitmap;
		} catch (RuntimeException re) {
			throw new RuntimeException(re.getMessage(), re);
		}
	}

	/**
	 * 将指定的url中的数据读入字节数组
	 * */
	private byte[] getBytes(String url, Bundle params) {
		try {
			HttpURLConnection conn = Utils.openConn(url, "post", params);
			ByteArrayOutputStream os = new ByteArrayOutputStream();
			byte[] buf = new byte[1024];
			InputStream is = conn.getInputStream();
			for (int i = 0; (i = is.read(buf)) > 0;) {
				os.write(buf, 0, i);
			}
			is.close();
			os.close();
			return os.toByteArray();
		} catch (Exception e) {
			Log.e(Utils.LOG_TAG, e.getMessage());
			throw new RuntimeException(e.getMessage(), e);
		}
	}

	public void Destroy() {

		Set<String> url = imageCache.keySet();
		Object[] urlStr = url.toArray();
		for (int i = 0; i < urlStr.length; i++) {
			SoftReference<Drawable> sd = imageCache
					.remove(urlStr[i].toString());
			if (sd != null) {
				sd = null;
			}
		}
	}

	public interface ImageCallback {
		public void imageLoaded(Drawable imageDrawable, String imageUrl);

		public void imageDefault();
	}

}