Android client single-thread download, android client single-Thread

Android client single-thread download, android client single-Thread

The specific effect is shown in. The specific operation steps are as follows:

1. Create an application named getDataInternet;

2. Modify the string. xml file in res/values. The Code is as follows:

1 <? Xml version = "1.0" encoding = "UTF-8"?> 2 <resources> 3 4 <string name = "app_name"> Android client single-threaded download </string> 5 <string name = "hello_world"> Hello world! </String> 6 <string name = "action_settings"> Settings </string> 7 <string name = "path"> image path </string> 8 <string name = "getBtnValue ""> get image </string> 9 10 </resources>

3. Compile the fragment_main.xml file in res/Layout. The specific code is as follows:

 1 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 2     xmlns:tools="http://schemas.android.com/tools" 3     android:layout_width="match_parent" 4     android:layout_height="match_parent" 5     android:paddingBottom="@dimen/activity_vertical_margin" 6     android:paddingLeft="@dimen/activity_horizontal_margin" 7     android:paddingRight="@dimen/activity_horizontal_margin" 8     android:paddingTop="@dimen/activity_vertical_margin" 9     tools:context="com.example.getdatatointernet.MainActivity$PlaceholderFragment" >10 11     <LinearLayout 12         android:layout_width="fill_parent"13         android:layout_height="fill_parent"14         android:orientation="vertical"15         >16         <TextView 17             android:layout_width="fill_parent"18             android:layout_height="wrap_content"19             android:text="@string/path"20             />21         <EditText 22             android:layout_width="fill_parent"23             android:layout_height="wrap_content"24             android:text="http://b.hiphotos.baidu.com/image/pic/item/1ad5ad6eddc451da70d0dc8db4fd5266d01632b6.jpg"25             android:id="@+id/path"26             />27         <Button 28             android:layout_width="wrap_content"29             android:layout_height="wrap_content"30             android:text="@string/getBtnValue"31             android:id="@+id/sendBtn"32             />33         <ImageView 34             android:layout_width="wrap_content"35             android:layout_height="wrap_content"36             android:id="@+id/imageView"37             />38     </LinearLayout>39 40 </RelativeLayout>

4. Compile the NetTool. java class, which is used to download images. The Code is as follows:

1 package com. example. getdatatointernet; 2 3 import java. io. byteArrayOutputStream; 4 import java. io. inputStream; 5 import java.net. httpURLConnection; 6 import java.net. URL; 7 8 public class NetTool {9 10 public static byte [] getImage (String path) throws Exception {11 // resume URL path 12 URL url = new URL (path ); 13 14 // get the HttpURLConnection object 15 HttpURLConnection conn = (HttpURLConnection) url. openConnection (); 16 c Onn. setRequestMethod ("GET"); // declares the Request Method 17 conn. setConnectTimeout (6*1000); // set link timeout 18 int a = conn. getResponseCode (); 19 if (conn. getResponseCode () == 200) 20 {21 InputStream iStream = conn. getInputStream (); // get the input stream 22 return readInstream (iStream); // return the resulting input stream 23} 24 25 return null; 26} 27 28 // read file stream content 29 public static byte [] readInstream (InputStream inputStream) throws Exception {30 // create ByteArrayOutputStream class 31 ByteA RrayOutputStream baoStream = new ByteArrayOutputStream (); 32 byte [] buffer = new byte [1024]; // declare the buffer 33 int length =-1; // define the default length of 34 while (length = inputStream. read (buffer ))! =-1) {35 baoStream. write (buffer, 0, length); // output the buffer to the memory 36} 37 38 baoStream. close (); // close output stream 39 inputStream. close (); // close the input stream 40 return baoStream. toByteArray (); // returns the byte array of the output stream 41} 42}View Code

5. Write the core code MainActivity. java class. The specific code is as follows:

1 package com. example. getdatatointernet; 2 3 import android. annotation. suppressLint; 4 import android. graphics. bitmap; 5 import android. graphics. bitmapFactory; 6 import android. OS. bundle; 7 import android. OS. strictMode; 8 import android. support. v4.app. fragment; 9 import android. support. v7.app. actionBarActivity; 10 import android. util. log; 11 import android. view. layoutInflater; 12 import android. view. menu; 13 import android. view. menuItem; 14 import android. view. view; 15 import android. view. viewGroup; 16 import android. widget. button; 17 import android. widget. editText; 18 import android. widget. imageView; 19 import android. widget. toast; 20 21 @ SuppressLint ("ValidFragment") 22 public class MainActivity extends ActionBarActivity {23 24 @ Override 25 protected void onCreate (Bundle savedInstanceState) {26 super. onCreate (savedInstanceState); 27 setContentView (R. layout. activity_main); 28 29 if (savedInstanceState = null) {30 getSupportFragmentManager (). beginTransaction () 31. add (R. id. container, new PlaceholderFragment ()). commit (); 32} 33} 34 35 @ Override 36 public boolean onCreateOptionsMenu (Menu menu) {37 38 // Inflate the menu; this adds items to the action bar if it is present. 39 getMenuInflater (). inflate (R. menu. main, menu); 40 return true; 41} 42 43 @ Override 44 public boolean onOptionsItemSelected (MenuItem item) {45 // Handle action bar item clicks here. the action bar will 46 // automatically handle clicks on the Home/Up button, so long 47 // as you specify a parent activity in AndroidManifest. xml. 48 int id = item. getItemId (); 49 if (id = R. id. action_settings) {50 return true; 51} 52 return super. onOptionsItemSelected (item); 53} 54 55/** 56 * A placeholder fragment containing a simple view. 57 */58 public class extends Fragment {59 60 public PlaceholderFragment () {61} 62 63 @ Override 64 public View onCreateView (LayoutInflater inflater, ViewGroup container, 65 Bundle savedInstanceState) {66 View rootView = inflater. inflate (R. layout. fragment_main, container, 67 false); 68 69 StrictMode. setThreadPolicy (new 70 StrictMode. threadPolicy. builder (). detectDiskReads (). detectDiskWrites (). detectNetwork (). penaltyLog (). build (); 71 StrictMode. setVmPolicy (72 new StrictMode. vmPolicy. builder (). detectLeakedSqlLiteObjects (). detectLeakedClosableObjects (). penaltyLog (). penaltyDeath (). build (); 73 74 final EditText imageText = (EditText) rootView. findViewById (R. id. path); 75 final ImageView imageView = (ImageView) rootView. findViewById (R. id. imageView); 76 final Button btn = (Button) rootView. findViewById (R. id. sendBtn); 77 78 btn. setOnClickListener (new View. onClickListener () {79 80 @ Override 81 public void onClick (View v) {82 // TODO Auto-generated method stub 83 String path = imageText. getText (). toString (); 84 try 85 {86 byte [] data = NetTool. getImage (path); 87 Bitmap bm = BitmapFactory. decodeByteArray (data, 0, data. length); 88 imageView. setImageBitmap (bm); 89} catch (Exception e) 90 {91 Log. I ("MyTest", e. getMessage (); 92 Toast. makeText (MainActivity. this, e. getMessage (), 1 ). show (); 93} 94} 95}); 96 return rootView; 97} 98} 99 100}View Code

6. Add service permissions to AndroidManifest. xml.

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