An example sharing of network resources for downloading URL addresses in Android _android

to obtain network resources through a URL and download a simple instance of a resource:

Package com.android.xiong.urltest; 
Import java.io.IOException; 
Import Java.io.InputStream; 
Import Java.io.OutputStream; 
Import java.net.MalformedURLException; 
 
Import Java.net.URL; 
Import android.app.Activity; 
Import Android.graphics.Bitmap; 
Import Android.graphics.BitmapFactory; 
Import Android.os.Bundle; 
Import Android.os.Handler; 
Import Android.os.Message; 
Import Android.view.Menu; 
 
Import Android.widget.ImageView; 
  public class Mainactivity extends activity {ImageView Show; 
  Bitmap Bitmap; Handler Handler = new Handler () {@Override public void Handlemessage (msg) {if (Msg.what = 0x 
 
      123) {///use ImageView to display the picture Show.setimagebitmap (bitmap); 
 
  } 
    } 
 
  }; 
    @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); 
    Setcontentview (R.layout.activity_main); 
 
    Show = (ImageView) Findviewbyid (r.id.show); 
     New Thread () {@Override public void Run () {//Defines a URL object URL url; 
          try {url = new URL ("Yun_qi_img/95506462.jpg"); 
          The resource input stream that opens the URL inputstream is = Url.openstream (); 
          The picture bitmap = Bitmapfactory.decodestream (IS) was parsed from the InputStream. 
          Send Message Handler.sendemptymessage (0x123); 
          Is.close (); 
          Again open RL corresponding resource input stream is = Url.openstream (); Open the phone file corresponding to the output stream outputstream OS = Openfileoutput ("Keqiang.") 
          JPG ", mode_append); 
          byte[] buff = new byte[1024]; 
          int hasread = 0; 
          Downloads the URL resource to the local while (Hasread = Is.read (buff)) > 0) {os.write (buff, 0, hasread); 
          } is.close (); 
        Os.close (); 
        catch (Malformedurlexception e) {//TODO auto-generated catch block E.printstacktrace (); catch (IOException e) {//TODO auto-generated catch BLock E.printstacktrace (); 
  }}.start (); @Override public boolean Oncreateoptionsmenu (Menu menu) {//Inflate the menu, this adds items to the Actio 
    n Bar if it is present. 
    Getmenuinflater (). Inflate (R.menu.main, menu); 
  return true; 
 } 
 
}

<linearlayout xmlns:android= "http://schemas.android.com/apk/res/android" 
  xmlns:tools= "http:// Schemas.android.com/tools " 
  android:layout_width=" match_parent " 
  android:layout_height=" Match_parent " 
  android:orientation= "vertical" 
  tools:context= ". Mainactivity "> 
 
  <imageview  
    android:id=" @+id/show " 
    android:layout_width=" Match_parent " android:layout_height= "Match_parent" 
    android:contentdescription= "@string/hello_world"/> 
 
</ Linearlayout> 

Multi-threaded download of network resources:

Package Com.example.threaddown; 
Import Java.util.Timer; 
 
Import Java.util.TimerTask; 
Import android.app.Activity; 
Import Android.os.Bundle; 
Import Android.os.Handler; 
Import Android.os.Message; 
Import Android.view.Menu; 
Import Android.view.View; 
Import Android.view.View.OnClickListener; 
Import Android.widget.Button; 
Import Android.widget.EditText; 
 
Import Android.widget.ProgressBar; 
  public class Mainactivity extends activity {edittext URL; 
  EditText Target; 
  Button downbn; 
  ProgressBar Bar; 
  Downutil Downutil; 
 
  private int mdownstatus; 
    @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); 
    Setcontentview (R.layout.activity_main); 
    Gets the three interface control URLs in the program interface = (edittext) Findviewbyid (R.id.url); 
    target = (edittext) Findviewbyid (r.id.target); 
    DOWNBN = (Button) Findviewbyid (R.ID.DOWNBN); 
    Bar = (ProgressBar) Findviewbyid (r.id.br); Create a Handler object final Handler Handler = new Handler () {@Override public void Handlemessage (msg) {if (Msg.what = = 0x123) { 
        Bar.setprogress (Mdownstatus); 
    } 
      } 
 
    }; Downbn.setonclicklistener (New Onclicklistener () {@Override public void OnClick (View v) {//Initialize D 
        Ownutil Object downutil = new Downutil (Url.gettext (). ToString (), Target. GetText (). ToString (), 6); 
              New Thread () {@Override public void run () {try {//start download 
 
            Downutil.download (); 
            catch (Exception e) {e.printstacktrace (); 
            //define the completion schedule per second of the system to receive the final timer timer = new timer (); Timer.schedule (New TimerTask () {@Override public void run () {//Get download task's 
          Percent Complete Double completerate = downutil. Getcompleterate ();      Mdownstatus = (int) (completerate * 1000); 
                Send a message to notify the expiration of the updated progress bar handler.sendemptymessage (0x123); 
                Cancel task Progress after download completes if (Mdownstatus >=) {timer.cancel (); 
          }}, 0, 1000); 
      }}.start (); 
  } 
    }); @Override public boolean Oncreateoptionsmenu (Menu menu) {//Inflate the menu, this adds items to the Actio 
    n Bar if it is present. 
    Getmenuinflater (). Inflate (R.menu.main, menu); 
  return true; 
 } 
 
}

Package Com.example.threaddown; 
Import java.io.IOException; 
Import Java.io.InputStream; 
Import Java.io.RandomAccessFile; 
Import java.net.HttpURLConnection; 
Import java.net.MalformedURLException; 
 
Import Java.net.URL; 
  public class Downutil {//define the path of the download resource private String path; 
  Specifies the location where the downloaded file is saved private String targetfile; 
  Define how many threads to use to download resources private int threadnum; 
  Define the downloaded thread object private downthread[] threads; 
 
  Defines the total size of the downloaded file private int fileSize; 
    Public Downutil (string path, string targetfile, int threadnum) {this.path = path; 
    This.targetfile = TargetFile; 
  This.threadnum = Threadnum; 
    The public void download () throws IOException {URL url = new URL (path); 
    HttpURLConnection conn = (httpurlconnection) url.openconnection (); 
    Conn.setconnecttimeout (5000); 
    Conn.setrequestmethod ("get"); 
    Conn.setrequestproperty ("Accept", "*/*"); 
    Conn.setrequestproperty ("Accept-language", "ZH-CN"); Conn.setrequestproperTy ("Charset", "UTF-8"); 
    Conn.setrequestproperty ("Connection", "keep-alive"); 
    Get the size of the file FileSize = Conn.getcontentlength (); 
    Conn.disconnect (); 
    int currentpartssize = filesize/threadnum + 1; 
    Randomaccessfile file = new Randomaccessfile (targetfile, "RW"); 
    Sets the size of the local file File.setlength (fileSize); 
    File.close (); 
      for (int i = 0; i < threadnum i++) {//Compute the download location of each thread int startpos = i * currentpartssize; 
      Each thread uses a randomaccessfile to download randomaccessfile current = new Randomaccessfile (targetfile, "RW"); 
      Define the download location of the thread Current.seek (startpos); 
      Create download thread Threads[i] = new Downthread (startpos, currentpartssize, current); 
    Start thread download Threads[i].start (); 
    //Get percent Complete of download public double getcompleterate () {///Statistics The total size of multiple threads already downloaded int sumsize = 0; 
    for (int i = 0; i < threadnum i++) {sumsize + = Threads[i].length; Return sumsize * 1.0/FILesize; 
    Private class Downthread extends thread {//define the location of the current thread download private int startpos; 
    Defines the size of the current thread download file private int currentpartssize; 
    The current thread downloads the file block private randomaccessfile Currentpart; 
 
    Defines the number of bytes that this thread has downloaded private int length; Public downthread (int startpos, int currentpartssize, Randomaccessfile currentpart) {this.startpos = Star 
      TPOs; 
      This.currentpart = Currentpart; 
 
    This.currentpartssize = currentpartssize; 
        @Override public void Run () {try {URL url = new URL (path); 
        HttpURLConnection conn = (httpurlconnection) URL. OpenConnection (); 
        Conn.setconnecttimeout (5000); 
        Conn.setrequestmethod ("get"); 
        Conn.setrequestproperty ("Accept", "*/*"); 
        Conn.setrequestproperty ("Accept-language", "ZH-CN"); 
        Conn.setrequestproperty ("Charset", "UTF-8"); 
        Conn.setrequestproperty ("Connection", "keep-alive"); INputstream in = Conn.getinputstream (); 
        In.skip (startpos); 
        int hasread = 0; 
        byte[] buffer = new byte[1024];  Read network data and write local files while (length < currentpartssize && (Hasread = in.read (buffer)) > 0) 
          {currentpart.write (buffer, 0, hasread); 
        Cumulative total size length + = Hasread for this thread download; 
        } currentpart.close (); 
 
      In.close (); 
      catch (Exception e) {e.printstacktrace (); 
 } 
 
    } 
 
  } 
 
}

<linearlayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http:// Schemas.android.com/tools "android:layout_width=" match_parent "android:layout_height=" Match_parent "Android:orien" tation= "Vertical" tools:context= ". Mainactivity "> <edittext android:id=" @+id/url "android:layout_width=" Match_parent "Android:layo" ut_height= "Wrap_content" android:text= "http://ksoap2-android.googlecode.com/svn/m2-repo/com/google/code/ Ksoap2-android/ksoap2-android-assembly/3.1.0/ksoap2-android-assembly-3.1.0-jar-with-dependencies.jar "/> <  
    EditText android:id= "@+id/target" android:layout_width= "match_parent" android:layout_height= "Wrap_content" android:text= "/mnt/sdcard/"/> <button android:id= "@+id/downbn" android:layout_width= NT "android:layout_height=" Wrap_content "android:text=" Down "/> <progressbar android:id=" @+id/br "Style="? android:attr/progressbarstylehorizontal "android:layout_width=" match_parent "android:layout_height=" Wrap_content "/>" 

 Lt;/linearlayout>

 <!--Create and delete files in SD cards--> <uses-permission android:name= " Android.permission.MOUNT_UNMOUNT_FILESYSTEMS "/> <!--permissions to write data in SD--> <uses-permission android:name=" Android.permission.WRITE_EXTERNAL_STORAGE "/> <!--access network permissions--> <uses-permission android:name=" Android.permission.INTERNET "/>