I have a JSON string, say a name and a Url . I need to extract name into the TextView and extract and display image in ImageView.
Below is the code for above scenario.
public static final String JSON_STRING="{\"WebImages\":{\"Imagename\":\"image_name\",\"imageurl\":http://www.example.com/image/example.png}}";
I need to display the name in TextView which I created, and fetch the image from that url and display in the Imageview.
First of all use Gson to parse Json and get url as a String, then you can use UniversalImageLoader library (it does the async image download and very easy to use) https://github.com/nostra13/Android-Universal-Image-Loader
static public DisplayImageOptions options= new DisplayImageOptions.Builder().cacheOnDisk(true).cacheInMemory(true).build();
imageLoader.displayImage(imgUrl, ivImage, options, new ImageLoadingListener() {
public void onLoadingStarted(String imageUri, View view) {
((ImageView)view).setImageResource(R.drawable.nofoto);
}
public void onLoadingFailed(String imageUri, View view, FailReason failReason) {
((ImageView)view).setImageResource(R.drawable.nofoto);
}
public void onLoadingComplete(String imageUri, View view, Bitmap loadedImage) {
}
public void onLoadingCancelled(String imageUri, View view) {
}
});
You could extract the image name and url like this
public static final String JSON_STRING="{\"WebImages\":{\"Imagename\":\"image_name\",\"imageurl\":http://www.example.com/image/example.png}}";
JSONObject jsonObject = new JSONObject(JSON_STRING);
JSONObject webImages = jsonObject.getJSONObject("WebImages");
String imageName = webImages.getString("Imagename");
String imageUrl = webImages.getString("imageurl");
Now, you have the imageName and the imageUrl. You can easily set the text doing something like myTextView.setText(imageName). For loading the image into ImageView, I suggest using the Picasso library. It is extremely easy to use. All you need is one line of code, which would look like
Picasso.with(context).load(imageUrl).into(imageView);
Use Universal Image Loader to load image very fast and smooth
You can use GSON library to parse the json into a plain Java Object and then use that object to fill in the TextView and ImageView. If you don't want to use external libraries you can use JSON classes like this:
JSONObject object = new JSONObject("your strnig");
JSONObject webimages = object.getJSONObject("WebImages");
String imageName = webimages.getString("image_name")
String imageUrl = webimages.getString("imageurl")
You can do something like this.
public static final String JSON_STRING="{"WebImages":{"Imagename":"image_name","imageurl":http://www.example.com/image/example.png}}";
private ImageLoader _ImageLoader;
try {
JSONObject _jObj = new JSONObject(JSON_STRING);
JSONObject _jSubObj = _jObj .getJSONObject("WebImages");
String _imageName= _jSubObj.getString("Imagename");
YOUR_TEXTVIEW.setText(_imageName);
String _imageURL= _jSubObj.getString("imageurl");
_ImageLoader = new ImageLoader(CURRENT_ACTIVITY.this);
_ImageLoader.DisplayImage(_imageURL,
R.drawable.ic_launcher, YOUR_IMAGEVIEW);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
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)
{
try {
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);
}
} catch (Exception e) {
e.printStackTrace();
}
}
private void queuePhoto(String url, ImageView imageView)
{
PhotoToLoad p=new PhotoToLoad(url, imageView);
executorService.submit(new PhotosLoader(p));
}
public 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;
}
}
public Bitmap getFacebookImage(String userId) {
// TODO Auto-generated method stub
Bitmap bitmap = null;
try {
HttpGet httpRequest = new HttpGet(
URI.create(userId));
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = (HttpResponse) httpclient
.execute(httpRequest);
HttpEntity entity = response.getEntity();
BufferedHttpEntity bufHttpEntity = new BufferedHttpEntity(
entity);
bitmap = BitmapFactory
.decodeStream(bufHttpEntity
.getContent());
httpRequest.abort();
} catch (Exception e) {
e.printStackTrace();
}
return bitmap;
}
//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=200;
// 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=1;
return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
} catch (FileNotFoundException e) {
}catch (Exception 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() {
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();
}
}
