Develop Reference

Release memory of Image Loader on android

I use ImageLoader to get images and show progress bar till image is been downloaded. This class is used by the ArrayAdapter to load images on to a GridView.
I want to know how to release image memory when the fragment that loads this gridview has been detached from the activity.
Also, is it expensive to store it in memory (i.e backstack) if several fragment transitions happen after loading this this view.
Here is my code
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
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;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.ProgressBar;
public class ImageLoader {
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
Activity activity = null;
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(5);
}
public void DisplayImage(String url, Activity activity,
ImageView imageView, ProgressBar p) {
imageViews.put(imageView, url);
this.activity = activity;
Bitmap bitmap = memoryCache.get(url);
if (bitmap != null) {
imageView.setImageBitmap(bitmap);
imageView.setTag("loaded");
imageView.setVisibility(View.VISIBLE);
p.setVisibility(View.GONE);
} else {
queuePhoto(url, imageView, p);
imageView.setImageResource(Utils.stub_id);
}
}
private void queuePhoto(String url, ImageView imageView, ProgressBar pb) {
PhotoToLoad p = new PhotoToLoad(url, imageView, activity, pb);
executorService.submit(new PhotosLoader(p));
}
private Bitmap getBitmap(String url) {
File f = fileCache.getFile(url);
// from SD cache
Bitmap b = decodeFile(f);
if (b != null)
return b;
// from web
try {
Bitmap bitmap = null;
URL imageUrl = new URL(url);
HttpURLConnection conn = (HttpURLConnection) imageUrl
.openConnection();
conn.setConnectTimeout(Utils.timeout);
conn.setReadTimeout(Utils.timeout);
conn.setInstanceFollowRedirects(true);
InputStream is = conn.getInputStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Exception ex) {
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;
BitmapFactory.decodeStream(new FileInputStream(f), null, o);
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = 70;
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;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
Activity activity;
public ProgressBar progressBar;
public PhotoToLoad(String u, ImageView i, Activity a, ProgressBar p) {
url = u;
imageView = i;
activity = a;
progressBar = p;
}
}
class PhotosLoader implements Runnable {
PhotoToLoad photoToLoad;
PhotosLoader(PhotoToLoad photoToLoad) {
this.photoToLoad = photoToLoad;
}
#Override
public void run() {
if (imageViewReused(photoToLoad))
return;
try {
Bitmap bmp = getBitmap(photoToLoad.url);
memoryCache.put(photoToLoad.url, bmp);
if (imageViewReused(photoToLoad))
return;
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad);
// Activity a = (Activity) photoToLoad.imageView.getContext();
photoToLoad.activity.runOnUiThread(bd);
} catch (Exception e) {
String s = e.getMessage();
}
}
}
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);
photoToLoad.imageView.setTag("loaded");
}
else
photoToLoad.imageView.setImageResource(Utils.stub_id);
photoToLoad.imageView.setVisibility(View.VISIBLE);
photoToLoad.progressBar.setVisibility(View.GONE);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}
public class MemoryCache {
private Map<String, SoftReference<Bitmap>> cache=Collections.synchronizedMap(new HashMap<String, SoftReference<Bitmap>>());
public Bitmap get(String id){
if(!cache.containsKey(id))
return null;
SoftReference<Bitmap> ref=cache.get(id);
return ref.get();
}
public void put(String id, Bitmap bitmap){
cache.put(id, new SoftReference<Bitmap>(bitmap));
}
public void clear() {
cache.clear();
}
}

You can use this method
MemoryCacheUtils.removeFromCache(url,ImageLoader.getInstance().getMemoryCache());
DiscCacheUtils.removeFromCache(url, ImageLoader.getInstance().getDiscCache());
or you can done it directly by
imageLoader.clearMemoryCache();
`

How To Set in Background Of Image View

i am New On Android I want set image in Background Which is getting from Url ..I am using ImageLoader Class
please Help me Set Image view In Background..
This Is MY Image Loader Class
public class ImageLoader {
// the simplest in-memory cache implementation. This should be replaced with
// something like SoftReference or BitmapOptions.inPurgeable(since 1.6)
private HashMap<String, Bitmap> cache = new HashMap<String, Bitmap>();
private File cacheDir;
static ArrayList<String> img_path = new ArrayList<String>();
static String sd_card_folder_name = "ImageLoader";
static int width;
public ImageLoader(Context context, Activity acc) {
// Make the background thead low priority. This way it will not affect
// the UI performance
photoLoaderThread.setPriority(Thread.NORM_PRIORITY - 1);
DisplayMetrics displaymetrics = new DisplayMetrics();
acc.getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
width = displaymetrics.widthPixels;
Log.d("width", "width = " + width);
cache.clear();
img_path = new ArrayList<String>();
// Find the dir to save cached images
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED))
cacheDir = new File(android.os.Environment
.getExternalStorageDirectory(), sd_card_folder_name);
else
cacheDir = context.getCacheDir();
if (!cacheDir.exists())
cacheDir.mkdirs();
}
final int stub_id = R.drawable.loader;
public void DisplayImage(String url, Activity activity, ImageView imageView) {
try {
String filename = String.valueOf(url.hashCode());
File[] file_array = cacheDir.listFiles();
for (int i = 0; i < file_array.length; i++) {
img_path.add(file_array[i].getName());
}
if (img_path.contains(filename)) {
imageView.setImageBitmap(BitmapFactory
.decodeFile("/mnt/sdcard/" + sd_card_folder_name + "/"
+ filename));
} else {
if (cache.containsKey(url)) {
imageView.setImageBitmap(cache.get(url));
} else {
queuePhoto(url, activity, imageView, filename);
imageView.setImageResource(stub_id);
}
}
} catch (Exception e) {
// TODO: handle exception
}
}
private void queuePhoto(String url, Activity activity, ImageView imageView, String _name) {
// This ImageView may be used for other images before. So there may be
// some old tasks in the queue. We need to discard them.
photosQueue.Clean(imageView);
PhotoToLoad p = new PhotoToLoad(url, imageView, _name);
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.push(p);
photosQueue.photosToLoad.notifyAll();
}
// start thread if it's not started yet
if (photoLoaderThread.getState() == Thread.State.NEW)
photoLoaderThread.start();
}
private Bitmap getBitmap(String url) {
// I identify images by hashcode. Not a perfect solution, good for the
// demo.
if (url != null && !(url.equals(""))) {
String filename = String.valueOf(url.hashCode());
File f = new File(cacheDir, filename);
/*
* // from SD cache Bitmap b = decodeFile(f); if (b != null) return
* b;
*/
// from web
try {
Bitmap bitmap = null;
InputStream is = new URL(url).openStream();
OutputStream os = new FileOutputStream(f);
Utils.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Exception ex) {
ex.printStackTrace();
return null;
}
}
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;
BitmapFactory.decodeStream(new FileInputStream(f), null, o);
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE=300;
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;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {
}
return null;
}
// Task for the queue
private class PhotoToLoad {
public String url;
public ImageView imageView;
public String _name;
public PhotoToLoad(String u, ImageView i, String n) {
url = u;
imageView = i;
_name = n;
}
}
PhotosQueue photosQueue = new PhotosQueue();
public void stopThread() {
photoLoaderThread.interrupt();
}
// stores list of photos to download
class PhotosQueue {
private Stack<PhotoToLoad> photosToLoad = new Stack<PhotoToLoad>();
// removes all instances of this ImageView
public void Clean(ImageView image) {
for (int j = 0; j < photosToLoad.size();) {
if (photosToLoad.get(j).imageView == image)
photosToLoad.remove(j);
else
++j;
}
}
}
class PhotosLoader extends Thread {
public void run() {
try {
while (true) {
// thread waits until there are any images to load in the
// queue
if (photosQueue.photosToLoad.size() == 0)
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.wait();
}
if (photosQueue.photosToLoad.size() != 0) {
PhotoToLoad photoToLoad;
synchronized (photosQueue.photosToLoad) {
photoToLoad = photosQueue.photosToLoad.pop();
}
Bitmap bmp = getBitmap(photoToLoad.url);
cache.put(photoToLoad.url, bmp);
Object tag = photoToLoad.imageView.getTag();
String FileName = photoToLoad._name;
if (FileName != null
&& ((String) FileName).equals(photoToLoad._name)) {
BitmapDisplayer bd = new BitmapDisplayer(bmp,
photoToLoad.imageView, FileName);
Activity a = (Activity) photoToLoad.imageView
.getContext();
a.runOnUiThread(bd);
}
}
if (Thread.interrupted())
break;
}
} catch (InterruptedException e) {
// allow thread to exit
}
}
}
PhotosLoader photoLoaderThread = new PhotosLoader();
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
ImageView imageView;
String file_name;
public BitmapDisplayer(Bitmap b, ImageView i, String _name) {
bitmap = b;
imageView = i;
file_name = _name;
}
public void run() {
if (bitmap != null) {
load_full_image(imageView, file_name, bitmap);
} else
imageView.setImageResource(stub_id);
}
}
private Runnable mMyRunnable = new Runnable() {
#Override
public void run() {
}
};
public void load_full_image(ImageView img, String _name, Bitmap btmp) {
img_path = new ArrayList<String>();
File[] file_array = cacheDir.listFiles();
for (int i = 0; i < file_array.length; i++) {
img_path.add(file_array[i].getName());
}
if (img_path.contains(_name)) {
img.setImageBitmap(BitmapFactory
.decodeFile("/mnt/sdcard/" + sd_card_folder_name + "/"
+ _name));
} else {
img.setImageBitmap(btmp);
}
}
public void clearCache() {
// clear memory cache
cache.clear();
// clear SD cache
File[] files = cacheDir.listFiles();
for (File f : files)
f.delete();
}
this is my Activity Where I Get Image In imagview
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.userprofile);
Button addfrnd=(Button)findViewById(R.id.addfrnd);
ImageView image = (ImageView) findViewById(R.id.imageView1);
UserModel user = (UserModel) getIntent().getSerializableExtra("User");
UserByIdModel tempuser = (UserByIdModel) getIntent().getSerializableExtra("UserById");
String UserId=String.valueOf(tempuser.getUser_Id());
String image_url=tempuser.getUser_Image();
int loader = R.drawable.loader;
ImageLoader imgLoader = new ImageLoader(getApplicationContext(),
UserByIdProfile.this);
image.setTag(image_url);
// whenever you want to load an image from url
// call DisplayImage function
// url - image url to load
// loader - loader image, will be displayed before getting image
// image - ImageView
imgLoader.DisplayImage(image_url, UserByIdProfile.this, image);

you have to change in load_full_image method of imageLoader class, like below
public class ImageLoader {
...
Context mContext;
...
public ImageLoader(Context context, Activity acc) {
...
mContext = context
....
}
public void load_full_image(ImageView img, String _name, Bitmap btmp) {
img_path = new ArrayList<String>();
File[] file_array = cacheDir.listFiles();
for (int i = 0; i < file_array.length; i++) {
img_path.add(file_array[i].getName());
}
if (img_path.contains(_name)) {
Drawable d = new BitmapDrawable(mContext.getResources(),BitmapFactory
.decodeFile("/mnt/sdcard/" + sd_card_folder_name + "/"
+ _name));
img.setBackground(d);
} else {
Drawable d = new BitmapDrawable(mContext.getResources(),btmp);
img.setBackground(d);
}
}
}
try this code may be it will work

You have created a instance of ImageLoader but have not Initialize ImageLoader. For this add this line of code in your constructor after imageLoader = ImageLoader.getInstance(); :
imageLoader.init(ImageLoaderConfiguration.createDefault(ctx));
You have not declared any option for your imageLoader. Modify your DisplayImageOptions code as below:
DisplayImageOptions options = new DisplayImageOptions.Builder() .showImageOnLoading(R.drawable.image_loading) .showImageForEmptyUri(R.drawable.no_image) .showImageOnFail(R.drawable.image_failed) .cacheInMemory(true) .cacheOnDisc(true) .bitmapConfig(Bitmap.Config.RGB_565) .build();

[Use this project aims to provide a reusable instrument for asynchronous image loading, caching and displaying.][1]
Features
1)Multithread image loading (async or sync)
2)Wide customization of ImageLoader's configuration (thread executors, downloader, decoder, 3)memory and disk cache, display image options, etc.)
4)Many customization options for every display image call (stub images, caching switch, decoding options, Bitmap processing and displaying, etc.)
5)Image caching in memory and/or on disk (device's file system or SD card)
6)Listening loading process (including downloading progress)
*****Android 2.0+ support
[1]: https://github.com/nostra13/Android-Universal-Image-Loader

scale the size of downloaded image to fit the imageview

This is my first time working with a ListView, and here is my problem :
I have an Imageloader class that downloads, decodes and scales images from the internet (from parse.com). The whole process works fine, but when the image is loaded on the imageview it doesn't fit the parent width...I'm trying to have something similar to instagram's display with a square image that fills the entire screen regardless of the used device.
this is what I have actually : http://i.imgur.com/OMDyG8I.jpg
this is what I want : http://i.imgur.com/nGHADzK.jpg
I used the Imageloader.java that I found on a tutorial and I don't really understandd how it really works. So if you guys could explain to me how it does so i can adapt it to have a square full screen image on my listview. thanks in advance :)
this is my ImageLoader.java (Nothing special on my layout for now...only an imageview with match-parent height and witdh):
package com.hichamridouane.smartshop;
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;
importenter code here 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;
import android.os.Handler;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;
public class ImageLoader {
MemoryCache memoryCache = new MemoryCache();
FileCache fileCache;
private Map<ImageView, String> imageViews = Collections
.synchronizedMap(new WeakHashMap<ImageView, String>());
ExecutorService executorService;
// Handler to display images in UI thread
Handler handler = new Handler();
public ImageLoader(Context context) {
fileCache = new FileCache(context);
executorService = Executors.newFixedThreadPool(5);
}
final int stub_id = R.drawable.temp_img;
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(stub_id);
}
}
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;
// Download Images from the Internet
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);
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 = 600;
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) {
} 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;
}
}
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(stub_id);
}
}
public void clearCache() {
memoryCache.clear();
fileCache.clear();
}
}

First of all, your decodeFile() method, which supposed to decode the image file from cache and resize it to smaller bitmap, will not resize it to a SQUARE SIZE. so, when you load your decoded bitmap into your ImageView, without any specified option in your layout or in your ImageView, you will get your image with original respect ratio.
What I suggest here is:
Fix your width and height of your ImageView in your layout. (I'm not sure it works because of the difference between devices' screen size)
I'm using this custom ImageView to show every ImageView in square:
Custom Square ImageView
and here is an example of using it in an xml layout:
<your.package.to.ENESquareImageView
android:id="#+id/mini_cover"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:contentDescription="#null"
android:scaleType="centerCrop" />
Hope this helps.

Android Loading More Images in Listview

I am using below Url Recipe but when i am frequently running application, its leads to out of memory issue(OOM), Can any one send updated ImageLoader which can load images(thumb nail) instantly and save into cache. thanks in advance.
http://codehenge.net/blog/2011/06/android-development-tutorial-asynchronous-lazy-loading-and-caching-of-listview-images/

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.util.HashMap;
import java.util.Stack;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.widget.ImageView;
public class ImageLoader {
// the simplest in-memory cache implementation. This should be replaced with
// something like SoftReference or BitmapOptions.inPurgeable(since 1.6)
private HashMap<String, Bitmap> cache = new HashMap<String, Bitmap>();
private File cacheDir;
private Context ctx;
public ImageLoader(Context context) {
// Make the background thead low priority. This way it will not affect
// the UI performance
photoLoaderThread.setPriority(Thread.NORM_PRIORITY - 1);
ctx = context;
// Find the dir to save cached images
if (android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED))
cacheDir = new File(
android.os.Environment.getExternalStorageDirectory(),
".abcde");
else
cacheDir = context.getCacheDir();
if (!cacheDir.exists())
cacheDir.mkdirs();
}
final int stub_id = R.drawable.no_image;
public void DisplayImage(String url, Activity activity, ImageView imageView) {
if (cache.containsKey(url)) {
imageView.setImageBitmap(cache.get(url));
} else {
queuePhoto(url, activity, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, Activity activity, ImageView imageView) {
// This ImageView may be used for other images before. So there may be
// some old tasks in the queue. We need to discard them.
photosQueue.Clean(imageView);
PhotoToLoad p = new PhotoToLoad(url, imageView);
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.push(p);
photosQueue.photosToLoad.notifyAll();
}
// start thread if it's not started yet
if (photoLoaderThread.getState() == Thread.State.NEW)
photoLoaderThread.start();
}
public Bitmap getBitmap(String urlString) {
String filename = String.valueOf(urlString.substring(urlString
.lastIndexOf("/") + 1));
File f = new File(cacheDir, filename);
try {
if (!f.exists()) {
Bitmap bitmap = null;
InputStream is = new URL(urlString).openStream();
OutputStream os = new FileOutputStream(f);
Globals.CopyStream(is, os);
os.close();
bitmap = decodeFile(f);
return bitmap;
} else {
Bitmap bitmap = decodeFile(f);
return bitmap;
}
} catch (Exception ex) {
ex.printStackTrace();
Log.e(Data.LOG, ex.getMessage(), ex);
Bitmap icon = BitmapFactory.decodeResource(ctx.getResources(),
R.drawable.no_image);
return icon;
}
}
// 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;
BitmapFactory.decodeStream(new FileInputStream(f), null, o);
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = 70;
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++;
}
// decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {
}
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;
}
}
PhotosQueue photosQueue = new PhotosQueue();
public void stopThread() {
photoLoaderThread.interrupt();
}
// stores list of photos to download
class PhotosQueue {
private Stack<PhotoToLoad> photosToLoad = new Stack<PhotoToLoad>();
// removes all instances of this ImageView
public void Clean(ImageView image) {
for (int j = 0; j < photosToLoad.size();) {
if (photosToLoad.get(j).imageView == image)
photosToLoad.remove(j);
else
++j;
}
}
}
class PhotosLoader extends Thread {
#Override
public void run() {
try {
while (true) {
if (photosQueue.photosToLoad.size() == 0)
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.wait();
}
if (photosQueue.photosToLoad.size() != 0) {
PhotoToLoad photoToLoad;
synchronized (photosQueue.photosToLoad) {
photoToLoad = photosQueue.photosToLoad.pop();
}
Bitmap bmp = getBitmap(photoToLoad.url);
cache.put(photoToLoad.url, bmp);
if (photoToLoad.url == null) {
} else {
if (((String) photoToLoad.imageView.getTag())
.equals(photoToLoad.url)) {
BitmapDisplayer bd = new BitmapDisplayer(bmp,
photoToLoad.imageView);
Activity a = (Activity) photoToLoad.imageView
.getContext();
a.runOnUiThread(bd);
}
}
}
if (Thread.interrupted())
break;
}
} catch (InterruptedException e) {
// allow thread to exit
}
}
}
PhotosLoader photoLoaderThread = new PhotosLoader();
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
ImageView imageView;
public BitmapDisplayer(Bitmap b, ImageView i) {
bitmap = b;
imageView = i;
}
public void run() {
if (bitmap != null)
imageView.setImageBitmap(bitmap);
else
imageView.setImageResource(stub_id);
}
}
public void clearCache() {
cache.clear();
// clear SD cache
File[] files = cacheDir.listFiles();
for (File f : files)
f.delete();
}
}

app is slow with images in android

I am doing a app on images to show them in GridView, i am fetching 20 images from server. Resolution of the each image is 720*540.I used JSON parsing to fetch url and used below code to convert into Bitmap in order to set images.
public static Bitmap loadImageFromUrl(String url) {
InputStream inputStream;Bitmap b;
try {
inputStream = (InputStream) new URL(url).getContent();
BitmapFactory.Options bpo= new BitmapFactory.Options();
if(bpo.outWidth>500) {
bpo.inSampleSize=8;
b=BitmapFactory.decodeStream(inputStream, null,bpo );
} else {
bpo.inSampleSize=2;
b=BitmapFactory.decodeStream(inputStream, null,bpo );
}
return b;
} catch (IOException e) {
throw new RuntimeException(e);
}
}
my app is working fine but it is taking too much time to load the images. So that my app became slow. Should i decrease the resolution of images?
how to come out of the issue?

If you are doing a grid view to load 20 images of such resolution, I would suggest the following:
Definitely reduce the size of the images. Unless you are targeting a tablet, you will be fine as most smartphones cannot achieve that resolution with 20 images.
Cache images if you can.
Download the images on a different thread. Store a HashMap would make it easy for you, just put all the imageviews with the image file names or other form of IDs as keys. send message to your Handler when images are downloaded and update the view after it's decoded. You can retrieve your views directly. Just remember to check if they are still in the window. This way the images will show up one after another quickly. I don't think multithreading the images will help, just make sure to use another thread to "push the images" and the main UI thread updates. User experience will be greatly improved then.
Hope this helps.
---some implementations, I don't have the complete code with me right now---
Have a data structure to match the views with data that comes in. very handy here.
private HashMap<String,ImageView> pictures;
When you get the list of image urls, iterate through them:
pictures.put(id,view);
try{
FileInputStream in = openFileInput(id);
Bitmap bitmap = null;
bitmap = BitmapFactory.decodeStream(in, null, null);
view.setImageBitmap(bitmap);
}catch(Exception e){
new Thread(new PictureGetter(this,mHandler,id)).start();
}
(Here the picture getter will simply fetch the image if it is not cached already and cache it)
Code to update the image view:
if(id!=null){
ImageView iv = pictures.get(id);
if(iv!=null){
try{
FileInputStream in = openFileInput(id);
Bitmap bitmap = null;
bitmap = BitmapFactory.decodeStream(in, null, null);
iv.setImageBitmap(bitmap);
}catch(Exception e){
}
}

Picasso library
Solution is instead of using bitmap to load image directly use a awesome Library called Picasso its just super fast i know you really love this you can do this like this
Add picasso jar file to your project (Download picasso jar file here) Use picasso to load the Image like this
Picasso.with(context).load(new File(title)).centerCrop()
.resize(150, 150).error(R.drawable.ic_launcher).into(image);
where title is the image path which you want to load. Crop,resize, error are optional.

I'm guessing that most of the loading time is because of the large amount of images combined with the size of the images.
There are 2 possible solutions:
Resize the images, or lower the quality of the images so that the filesize is below 75kb or so.
Use multi-threading to retrieve multiple images at once. This might not help if the user's connection is really slow, but if you combine this with a small enough filesize it might just help out enough. You might want to determine what the current bandwidth of the device is and base the number of threads you run on that.
For instance: 20 images of 75KB each and an available connection of 200 KB/s = 3 or 4 concurrent threads.
Hope this helps.

I have same problem in my android app. When you decode a bitmap from a big sized image and set as imageBitmap to an image view probably your application will slow and after a few try you'll get an "out of memory exception"
Two of the possible ways you can try to handle this problem:
1- Reduce bitmap size when you decode from file
2- Use an image library.
I prefered second way and used Universal Image Loader. https://github.com/nostra13/Android-Universal-Image-Loader
String url = "file://" + your_file_path
com.nostra13.universalimageloader.core.ImageLoader.getInstance().displayImage(url, ivPicture, options);

public class clothImageLoader {
// the simplest in-memory cache implementation. This should be replaced with
// something like SoftReference or BitmapOptions.inPurgeable(since 1.6)
// public static HashMap<String, Bitmap> cache = new HashMap<String,
// Bitmap>();
private static File cacheDir;
public clothImageLoader(Context context) {
// Make the background thead low priority. This way it will not affect
// the UI performance
photoLoaderThread.setPriority(Thread.NORM_PRIORITY - 1);
// Find the dir to save cached images
if (android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED))
// cacheDir=new
// File(android.os.Environment.getExternalStorageDirectory(),"LazyList");
cacheDir = new File(ConstValue.MY_ClothBitmap_DIR);
else
cacheDir = context.getCacheDir();
if (!cacheDir.exists())
cacheDir.mkdirs();
}
final int stub_id = R.drawable.icon;
public void DisplayImage(String url, Activity activity, ImageView imageView) {
if (ConstValue.ClothRoomcache.containsKey(url))
imageView.setImageBitmap(ConstValue.ClothRoomcache.get(url));
else {
queuePhoto(url, activity, imageView);
imageView.setImageResource(stub_id);
}
}
private void queuePhoto(String url, Activity activity, ImageView imageView) {
// This ImageView may be used for other images before. So there may be
// some old tasks in the queue. We need to discard them.
photosQueue.Clean(imageView);
PhotoToLoad p = new PhotoToLoad(url, imageView);
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.push(p);
photosQueue.photosToLoad.notifyAll();
}
// start thread if it's not started yet
if (photoLoaderThread.getState() == Thread.State.NEW)
photoLoaderThread.start();
}
private Bitmap getBitmap(String url) {
// I identify images by hashcode. Not a perfect solution, good for the
// demo.
String filename = String.valueOf(url.hashCode());
File f = new File(cacheDir, filename);
// from SD cache
Bitmap b = decodeFile(f);
if (b != null)
return b;
// from web
try {
Bitmap bitmap = null;
/*
* InputStream is=new URL(url).openStream(); OutputStream os = new
* FileOutputStream(f); Utils.CopyStream(is, os); os.close();
*/
URL url1 = new URL(url);
bitmap = decodeFile(f);
/* Open a connection to that URL. */
URLConnection ucon = url1.openConnection();
/*
* Define InputStreams to read from the URLConnection.
*/
InputStream is = ucon.getInputStream();
// FlushedInputStream a = new FlushedInputStream(is);
BufferedInputStream bis = new BufferedInputStream(is);
/*
* Read bytes to the Buffer until there is nothing more to read(-1).
*/
ByteArrayBuffer baf = new ByteArrayBuffer(5000);
int current = 0;
while ((current = bis.read()) != -1) {
baf.append((byte) current);
}
/* Convert the Bytes read to a String. */
FileOutputStream fos = new FileOutputStream(f);
fos.write(baf.toByteArray());
fos.flush();
fos.close();
bitmap = decodeFile(f);
return bitmap;
} catch (Exception ex) {
ex.printStackTrace();
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;
BitmapFactory.decodeStream(new FileInputStream(f), null, o);
// Find the correct scale value. It should be the power of 2.
final int REQUIRED_SIZE = ConstValue.bmpSize;
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++;
}
// decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {
}
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;
}
}
PhotosQueue photosQueue = new PhotosQueue();
public void stopThread() {
photoLoaderThread.interrupt();
}
// stores list of photos to download
class PhotosQueue {
private Stack<PhotoToLoad> photosToLoad = new Stack<PhotoToLoad>();
// removes all instances of this ImageView
public void Clean(ImageView image) {
for (int j = 0; j < photosToLoad.size();) {
if (photosToLoad.get(j).imageView == image)
photosToLoad.remove(j);
else
++j;
}
}
}
class PhotosLoader extends Thread {
public void run() {
try {
while (true) {
// thread waits until there are any images to load in the
// queue
if (photosQueue.photosToLoad.size() == 0)
synchronized (photosQueue.photosToLoad) {
photosQueue.photosToLoad.wait();
}
if (photosQueue.photosToLoad.size() != 0) {
PhotoToLoad photoToLoad;
synchronized (photosQueue.photosToLoad) {
photoToLoad = photosQueue.photosToLoad.pop();
// photoToLoad=photosQueue.photosToLoad.get(0);
// photosQueue.photosToLoad.remove(photoToLoad);
}
Bitmap bmp = getBitmap(photoToLoad.url);
ConstValue.ClothRoomcache.put(photoToLoad.url, bmp);
if (((String) photoToLoad.imageView.getTag()).equals(photoToLoad.url)) {
BitmapDisplayer bd = new BitmapDisplayer(bmp, photoToLoad.imageView);
Activity a = (Activity) photoToLoad.imageView.getContext();
a.runOnUiThread(bd);
}
}
if (Thread.interrupted())
break;
}
} catch (InterruptedException e) {
// allow thread to exit
}
}
}
PhotosLoader photoLoaderThread = new PhotosLoader();
// Used to display bitmap in the UI thread
class BitmapDisplayer implements Runnable {
Bitmap bitmap;
ImageView imageView;
public BitmapDisplayer(Bitmap b, ImageView i) {
bitmap = b;
imageView = i;
}
public void run() {
if (bitmap != null)
imageView.setImageBitmap(bitmap);
else
imageView.setImageResource(stub_id);
}
}
public static void clearCache() {
// clear memory cache
ConstValue.ClothRoomcache.clear();
// clear SD cache
File[] files = cacheDir.listFiles();
for (File f : files)
f.delete();
}
public class FlushedInputStream extends FilterInputStream {
public FlushedInputStream(InputStream inputStream) {
super(inputStream);
}
#Override
public long skip(long n) throws IOException {
long totalBytesSkipped = 0L;
while (totalBytesSkipped < n) {
long bytesSkipped = in.skip(n - totalBytesSkipped);
if (bytesSkipped == 0L) {
int a = read();
if (a < 0) {
break; // we reached EOF
} else {
bytesSkipped = 1; // we read one byte
}
}
totalBytesSkipped += bytesSkipped;
}
return totalBytesSkipped;
}
}
}
when you call the method ,in the gridView getView method:
holder.image.setTag(ChoseInfo.get(position).getLink());
imageLoader.DisplayImage(ChoseInfo.get(position).getLink(), activity, holder.image);
ChoseInfo.get(position).getLink())
Here getLink() is internet link.