package com.xiangyixie.picshouse.cache; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.os.Handler; import android.widget.ImageView; import com.xiangyixie.picshouse.Cache.DiskCache; import com.xiangyixie.picshouse.Cache.MemoryCache; import com.xiangyixie.picshouse.R; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.HttpURLConnection; import java.net.URL; import java.util.Collections; import java.util.Map; import java.util.WeakHashMap; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; public class ImageLoader { MemoryCache memoryCache = new MemoryCache(); DiskCache fileCache; private Map<ImageView, String> imageViews = Collections.synchronizedMap(new WeakHashMap<ImageView, String>()); ExecutorService executorService; Handler handler = new Handler();//handler to display images in UI thread public ImageLoader(Context context) { fileCache = new DiskCache(context); executorService = Executors.newFixedThreadPool(5); } public void DisplayImage(String url, ImageView imageView) { imageViews.put(imageView, url); Bitmap bitmap = memoryCache.get(url); if (bitmap != null) imageView.setImageBitmap(bitmap); else { queuePhoto(url, imageView); imageView.setImageResource(R.drawable.loading); } } private void queuePhoto(String url, ImageView imageView) { PhotoToLoad p = new PhotoToLoad(url, imageView); executorService.submit(new PhotosLoader(p)); } private Bitmap getBitmap(String url) { File f = fileCache.getFile(url); //read from SD cache Bitmap b = decodeFile(f); if (b != null) { return b; } //download from web try { Bitmap bitmap = null; URL imageUrl = new URL(url); HttpURLConnection conn = (HttpURLConnection) imageUrl.openConnection(); conn.setConnectTimeout(30000); conn.setReadTimeout(30000); conn.setInstanceFollowRedirects(true); InputStream is = conn.getInputStream(); OutputStream os = new FileOutputStream(f); //Utils.CopyStream(is, os); //download file int size = 0; byte[] buffer = new byte[1024]; while ((size = is.read(buffer)) != -1) { os.write(buffer, 0, size); } is.close(); os.close(); conn.disconnect(); bitmap = decodeFile(f); return bitmap; } catch (Throwable ex) { ex.printStackTrace(); if (ex instanceof OutOfMemoryError){ memoryCache.clear(); } return null; } } //decodes image and scales it to reduce memory consumption private Bitmap decodeFile(File f) { try { //decode image size BitmapFactory.Options o = new BitmapFactory.Options(); o.inJustDecodeBounds = true; FileInputStream stream1 = new FileInputStream(f); BitmapFactory.decodeStream(stream1, null, o); stream1.close(); //Find the correct scale value. It should be the power of 2. final int REQUIRED_SIZE = 128; int width_tmp = o.outWidth, height_tmp = o.outHeight; int scale = 1; while (true) { if (width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 < REQUIRED_SIZE) break; width_tmp /= 2; height_tmp /= 2; scale *= 2; } //decode with inSampleSize BitmapFactory.Options o2 = new BitmapFactory.Options(); o2.inSampleSize = scale; FileInputStream stream2 = new FileInputStream(f); Bitmap bitmap = BitmapFactory.decodeStream(stream2, null, o2); stream2.close(); return bitmap; } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return null; } //Task for the queue private class PhotoToLoad { public String url; public ImageView imageView; public PhotoToLoad(String u, ImageView i) { url = u; imageView = i; } } //background thread to load photo class PhotosLoader implements Runnable { PhotoToLoad photoToLoad; PhotosLoader(PhotoToLoad photoToLoad) { this.photoToLoad = photoToLoad; } @Override public void run() { try { if (imageViewReused(photoToLoad)) return; Bitmap bmp = getBitmap(photoToLoad.url); memoryCache.put(photoToLoad.url, bmp); if (imageViewReused(photoToLoad)) return; BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad); handler.post(bd); } catch (Throwable th) { th.printStackTrace(); } } } boolean imageViewReused(PhotoToLoad photoToLoad) { String tag = imageViews.get(photoToLoad.imageView); if (tag == null || !tag.equals(photoToLoad.url)) return true; return false; } //Used to display bitmap in the UI thread class BitmapDisplayer implements Runnable { Bitmap bitmap; PhotoToLoad photoToLoad; public BitmapDisplayer(Bitmap b, PhotoToLoad p) { bitmap = b; photoToLoad = p; } public void run() { if (imageViewReused(photoToLoad)) return; if (bitmap != null) photoToLoad.imageView.setImageBitmap(bitmap); else photoToLoad.imageView.setImageResource(R.drawable.loading); } } public void clearCache() { memoryCache.clear(); fileCache.clear(); } }