Android uses HttpClient to download images

In the previous chapter, Android uses HttpURLConnection to download images. In this chapter, HttpClient is used to download images.

Differences between HttpURLConnection and HttpClient:

HttpClient is a good open-source framework (org. appache. http) that encapsulates the request headers, parameters, content bodies, and responses for accessing http. It is more powerful to use.
HttpURLConnection is a standard java class that can implement simple URL-based request and response functions without encapsulation. It can be used in Taiyuan, such as custom re-access and some advanced functions.

Add HttpClient based on the previous chapter

Key download code <喎?http: www.bkjia.com kf ware vc " target="_blank" class="keylink"> VcD4KPHA + PHByZSBjbGFzcz0 = "brush: java;">/*** Get webpage content through Get ** @ param url * For example: http://preview.quanjing.com/is002/ev601-025.jpg * @ return * @ throws ClientProtocolException * @ throws IOException * @ date 2014.05.10 */public static Bitmap getHttpGetBitmap (String url) throws ClientProtocolException, IOException {Bitmap bitmap = null; // create a default connection HttpClient client = new DefaultHttpClient (); // create a Get method HttpGet Get = new HttpGet (url); // get the network response HttpResponse response = client.exe cute (get); // if the server returns OK! If (response. getStatusLine (). getStatusCode () = HttpStatus. SC _ OK) {InputStream is = response. getEntity (). getContent (); bitmap = BitmapFactory. decodeStream (is); is. close () ;}return bitmap ;}

Internet access permission

Activity download code

Package com. dzt. downloadimage; import java. io. IOException; import java.net. malformedURLException; import org. apache. http. client. clientProtocolException; import android. app. activity; import android. graphics. bitmap; import android. OS. asyncTask; import android. OS. bundle; import android. view. view; import android. view. view. onClickListener; import android. widget. button; import android. widget. imageView; import com. dz T. downloadimage. utils. httpUtils; public class MainActivity extends Activity implements OnClickListener {private Bitmap mDownloadImage = null; private ImageView image = null; private downloadImageTask task; private boolean _ isExe = false; @ Overrideprotected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_main); initWidgets (); task = new downloa DImageTask () ;}@ Overrideprotected void onStop () {// TODO Auto-generated method stubsuper. onStop (); if (_ isExe) {task. cancel (true); // cancel Operation} private void initWidgets () {image = (ImageView) findViewById (R. id. img); Button btn = (Button) findViewById (R. id. download_btn); btn. setOnClickListener (this) ;}@ Overridepublic void onClick (View v) {// TODO Auto-generated method stubswitch (v. getId () {case R. id. downl Oad_btn: if (! _ IsExe) cmdtask.exe cute ("http://preview.quanjing.com/is002/ev601-025.jpg"); // execute asynchronous operations _ isExe = true;} break; default: break;} class downloadImageTask extends AsyncTask
 
  
{@ Overrideprotected Boolean doInBackground (String... params) {// TODO Auto-generated method stubSystem. out. println ("[downloadImageTask->] doInBackground" + params [0]); // try {// mDownloadImage = HttpUtils. getNetWorkBitmap (params [0]); //} catch (MalformedURLException e) {// TODO Auto-generated catch block // e. printStackTrace (); //} catch (IOException e) {// TODO Auto-generated catch block // e. printStackTrace (); //} try {mDownloadImage = HttpUtils. getHttpGetBitmap (params [0]);} catch (ClientProtocolException e) {// TODO Auto-generated catch blocke. printStackTrace ();} catch (IOException e) {// TODO Auto-generated catch blocke. printStackTrace ();} return true;} // callback for download completion @ Overrideprotected void onPostExecute (Boolean result) {// TODO Auto-generated method stubimage. setImageBitmap (mDownloadImage); System. out. println ("result =" + result); super. onPostExecute (result);} // Update Progress callback @ Overrideprotected void onProgressUpdate (Integer... values) {// TODO Auto-generated method stubsuper. onProgressUpdate (values );}}}
 

If the image size is large, the download may fail.

Demo: http://download.csdn.net/detail/deng0zhaotai/7326167