androidimageconnectionandroid-imageservercontrol

How could I download and view images in imageview in Android?


I'm trying to display two images from my server. How could I achieve this?

Any options available in Android to change the image dynamically from the server for every instance?

I'm using permission as,.

 <uses-permission android:name="android.permission.INTERNET" />

Solution

  • Try this example. it will help you get the images fromonline

    The Xml File is

    <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dip"
        android:text="Loading image from url" />
    
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />
    
    <ImageView
        android:id="@+id/image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dip" />
    
    <ImageView
        android:id="@+id/image1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dip" />
    
    <ImageView
        android:id="@+id/image2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dip" />
    
    <ImageView
        android:id="@+id/image3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="10dip" />
     </LinearLayout>
    

    And java files are,..

    public class AndroidLoadImageFromURLActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    
        // Loader image - will be shown before loading image
        final int loader = R.drawable.loader;
    
        // Imageview to show
        final ImageView image = (ImageView) findViewById(R.id.image);
        final ImageView image1 = (ImageView) findViewById(R.id.image1);
        final ImageView image2 = (ImageView) findViewById(R.id.image2);
        final ImageView image3 = (ImageView) findViewById(R.id.image3);
        Button b=(Button)findViewById(R.id.button1);
    
    
        // Image url
        final String image_url = "URL";
        final String image_url2 = "URL";
        final String image_url3 = "URL";
        final String image_url4 = "URL";
    
        // ImageLoader class instance
        final ImageLoader imgLoader = new ImageLoader(getApplicationContext());
    
        // 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 
        b.setOnClickListener(new OnClickListener() {
    
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
    
    
        imgLoader.DisplayImage(image_url, loader, image);
        imgLoader.DisplayImage(image_url4, loader, image3);
        imgLoader.DisplayImage(image_url2, loader, image1);
        imgLoader.DisplayImage(image_url3, loader, image2);
            }
        });
    }
    }
    
    public class FileCache {
    
    private File cacheDir;
    
    public FileCache(Context 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(),"TempImages");
        else
            cacheDir=context.getCacheDir();
        if(!cacheDir.exists())
            cacheDir.mkdirs();
    }
    
    public File getFile(String url){
        String filename=String.valueOf(url.hashCode());
        File f = new File(cacheDir, filename);
        return f;
    
    }
    
    public void clear(){
        File[] files=cacheDir.listFiles();
        if(files==null)
            return;
        for(File f:files)
            f.delete();
    }
    
    }
    
    public class ImageLoader {
    
    MemoryCache memoryCache=new MemoryCache();
    FileCache fileCache;
    private Map<ImageView, String> imageViews=Collections.synchronizedMap(new WeakHashMap<ImageView, String>());
    ExecutorService executorService; 
    
    public ImageLoader(Context context){
        fileCache=new FileCache(context);
        executorService=Executors.newFixedThreadPool(5);
    }
    
    int stub_id = R.drawable.ic_launcher;
    public void DisplayImage(String url, int loader, ImageView imageView)
    {
        stub_id = loader;
        imageViews.put(imageView, url);
        Bitmap bitmap=memoryCache.get(url);
        if(bitmap!=null)
            imageView.setImageBitmap(bitmap);
        else
        {
            queuePhoto(url, imageView);
            imageView.setImageResource(loader);
        }
    }
    
    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);
    
        //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(30000);
            conn.setReadTimeout(30000);
            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){
           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=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;
        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() {
            if(imageViewReused(photoToLoad))
                return;
            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();
            a.runOnUiThread(bd);
        }
    }
    
    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();
    }
    
    }
    
    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();
    }
    }
    
    
    public class Utils {
    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){}
    }
    }
    

    And use the Manifest.xml as,..

    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.androidhive.imagefromurl"
    android:versionCode="1"
    android:versionName="1.0" >
    
    <uses-sdk android:minSdkVersion="8" />
    
    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".AndroidLoadImageFromURLActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
    
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    
    <!-- Internet Permissions -->
    <uses-permission android:name="android.permission.INTERNET" />
    
    <!-- Permission to write to external storage -->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    
    </manifest>