Android Network Programming uses HttpClient to access the web site

Android Network Programming uses HttpClient to access the web site

The HttpClientDemo. java Interface contains two buttons and a text box.

/** Use HttpClientlai to submit access requests, receive responses * A, send GET request * 1, create HttpClient object; HttpClient httpclient = new DefaultHttpClient (); * 2, send GET request, create HttpGet object: HttpGet httpget = new HttpGet ("http://www.baidu.com"); * 3, using the HttpClient object to implement the HttpGet object will get the server response object HttpResponse object, the response is encapsulated in HttpResponse: * HttpResponse httpresponse=httpclient.exe cute (httpget); * 4. Obtain the Http instance HttpEntity entity = httpresponse from the httpresponse response. getEntity (); **/publi C class HttpClientDemo extends Activity {TextView response; // declare the HttpClient object HttpClient httpclient; Handler handler = new Handler () {public void handleMessage (Message msg) {if (msg. what = 0x123) {// use response to display the response of the server. append (msg. obj. toString () + "\ n") ;}};@ Override protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); setContentView (R. layout. activity_http _ Client); // 1. Create the DefaultHttpClient object. The HttpClient interface callback is an interface httpclient = new DefaultHttpClient (); response = (TextView) findViewById (R. id. response);}/** send GET request process to the service ***/public void accessSecret (View v) {response. setText (""); // click the button to enable the Thread and send the Get request new Thread () {public void run () {// 2, create an HttpGet object HttpGet httpget = new HttpGet ("http: // localhost: 8080/foo/secret. jsp "); // deploy jsp on To cat server try {// 3, use HttpC When the lient object implements the HttpGet object, the server will get the HttpResponse response object, and the response will be encapsulated in HttpResponse httpresponse=httpclient.exe cute (httpget); // 4, obtain the Http instance HttpEntity entity = httpresponse from the httpresponse response. getEntity (); if (entity! = Null) {// 5. The entity instance obtains the content, establishes an input stream, and reads the server content BufferedReader br = new BufferedReader (new InputStreamReader (entity. getContent (); String line = null; while (line = br. readLine ())! = Null) {// cyclically read content from the input stream Message msg = new Message (); msg. what = 0x123; msg. obj = line; handler. sendMessage (msg); // send it to the UI thread to update the UI component }}catch (ClientProtocolException e) {// TODO Auto-generated catch blocke. printStackTrace ();} catch (IOException e) {// TODO Auto-generated catch blocke. printStackTrace ();}}}. start ();}/** Post request process ***/public void showLogin (View v) {final View loginDialog = getLayoutInflater (). inflate (R. layout. login, null); new AlertDialog. builder (HttpClientDemo. this ). setTitle ("log on to the system "). setView (loginDialog ). setPositiveButton ("OK", new DialogInterface. onClickListener () {@ Overridepublic void onClick (DialogInterface dialog, int which) {// obtain the username and password of the dialog box final String name = (EditText) loginDialog. findViewById (R. id. name )). getText (). toString (); final String pass = (EditText) loginDialog. findViewById (R. id. pass )). getText (). toString (); // Click OK to enable the Thread. The Thread sends the Post request new Thread () {public void run () {try {// 2, create an HttpPost object HttpPost httppost = new HttpPost ("http: // localhost: 8080/foo/login. jsp "); // jsp is deployed on the To cat server // 3. It encapsulates the passed parameters. NameValuePair is a List of simple name values on the node type.
 
  
Params = new ArrayList
  
   
(); Params. add (new BasicNameValuePair ("name", name); // add the params parameter. add (new BasicNameValuePair ("pass", pass); // 3, sets the encoding httppost. setEntity (new UrlEncodedFormEntity (params, HTTP. UTF_8); // 4, The HttpClient object executes the HttpPost request to obtain the HttpResponse httpresponse#httpclient.exe cute (httppost); // 5, if the status code is 200, the server is successful. if (httpresponse. getStatusLine (). getStatusCode () = 200) {// 200: Response successful, 301/302: Redirection, 404: not found: no resource found, 501 server encountered an error, make it unable to provide service to the request String msg = EntityUtils. toString (httpresponse. getEntity (); loiter. prepare (); // prompt that the logon is successful Toast. makeText (HttpClientDemo. this, msg, Toast. LENGTH_LONG ). show (); logoff. loop () ;}} catch (ParseException e) {// TODO Auto-generated catch blocke. printStackTrace ();} catch (IOException e) {// TODO Auto-generated catch blocke. printStackTrace ();}}}. start ();}}). setNegativeButton ("cancel", null ). show ();}