created image loader

src/src/main/java/agency/techstar/imageloader/ImageLoader.java

@@ -1,8 +1,200 @@
 package agency.techstar.imageloader;
 
+import android.content.Context;
+import android.graphics.Bitmap;
+import android.graphics.BitmapFactory;
+import android.graphics.Color;
+import android.os.Handler;
+import android.widget.ImageView;
+
+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;
+
 /**
  * Created by turtuvshin on 10/14/17.
  */
 
 public class ImageLoader {
-}
+
+    MemoryCache memoryCache=new MemoryCache();
+    FileCache fileCache;
+    private Map<ImageView, String> imageViews= Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
+    ExecutorService executorService;
+    Handler handler=new Handler();
+
+    public ImageLoader(Context context){
+        fileCache=new FileCache(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);
+        }
+    }
+
+    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);
+
+        Bitmap b = decodeFile(f);
+        if(b!=null)
+            return b;
+
+        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);
+            copyStream(is, os);
+            os.close();
+            conn.disconnect();
+            bitmap = decodeFile(f);
+            return bitmap;
+        } catch (Throwable ex){
+            ex.printStackTrace();
+            if(ex instanceof OutOfMemoryError)
+                memoryCache.clear();
+            return null;
+        }
+    }
+
+    private Bitmap decodeFile(File f){
+        try {
+            BitmapFactory.Options o = new BitmapFactory.Options();
+            o.inJustDecodeBounds = true;
+            FileInputStream stream1=new FileInputStream(f);
+            BitmapFactory.decodeStream(stream1,null,o);
+            stream1.close();
+
+            final int REQUIRED_SIZE=140;
+            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;
+            }
+
+            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) {
+        }
+        catch (IOException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    private class PhotoToLoad
+    {
+        public String url;
+        public ImageView imageView;
+        public PhotoToLoad(String u, ImageView i){
+            url=u;
+            imageView=i;
+        }
+    }
+
+    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;
+    }
+
+    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.setBackgroundColor(Color.parseColor("#00000000"));
+        }
+    }
+
+    public void clearCache() {
+        memoryCache.clear();
+        fileCache.clear();
+    }
+
+    public static void copyStream(InputStream is, OutputStream os)
+    {
+        final int buffer_size=1024;
+        try
+        {
+            byte[] bytes=new byte[buffer_size];
+            for(;;)
+            {
+                int count=is.read(bytes, 0, buffer_size);
+                if(count==-1)
+                    break;
+                os.write(bytes, 0, count);
+            }
+        }
+        catch(Exception ex){}
+    }
+}