通过Android应用程序连接到PHP脚本[重复]

Question

This question already has an answer here:

• How do I fix android.os.NetworkOnMainThreadException? 54 answers

This is the code I have so far.

public void postData(String toPost) {
    // Create a new HttpClient and Post Header
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("http://www.mywebsite.com/dev/reverser.php");

    //This is the data to send
    String MyName = toPost; //any data to send

    try {
    // Add your data
    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
    nameValuePairs.add(new BasicNameValuePair("action", MyName));

    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

    // Execute HTTP Post Request

    ResponseHandler<String> responseHandler = new BasicResponseHandler();
    String response = httpclient.execute(httppost, responseHandler);

    //This is the response from a php application

    String reverseString = response;
    Toast.makeText(this, "response" + reverseString, Toast.LENGTH_LONG).show();

    } catch (ClientProtocolException e) {
    Toast.makeText(this, "CPE response " + e.toString(), Toast.LENGTH_LONG).show();
    // TODO Auto-generated catch block
    } catch (IOException e) {
    Toast.makeText(this, "IOE response " + e.toString(), Toast.LENGTH_LONG).show();
    // TODO Auto-generated catch block
    }

    }//end postData()

Can somebody please tell me what is wrong in the following code! I have established that there is a problem in the try catch block only and not anywhere else in the activity. I just do not know what it is or how to correct it.

My PHP code is quite simple. It is something like this -

//code to reverse the string
$reversed = strrev($_POST["action"]);
echo $reversed;

</div>

Answer 1

Adding as a seperate answer as the poster requests to do so .

Assumption :

a ) There is a text box that accepts the URL to load

b ) A button which when clicked performs the networking operation on the URL fetched f

Implement a button click listener that calls the following function :

    private void URL() 
    {
        String url = txtURL.getText().toString();
        new URLTask().execute(new String[] { url });
    }    




private class URLTask extends AsyncTask<String, Void, String> 
    {
        protected String doInBackground(String... urls)
        {

            BufferedReader br = null;
            String url = urls[0];
            StringBuffer sb = new StringBuffer("");

            try
            {
                HttpClient client = new DefaultHttpClient();
                HttpPost request = new HttpPost();
                request.setURI(new URI(url));

                List<NameValuePair> postParameters = new ArrayList<NameValuePair>();
                postParameters.add(new BasicNameValuePair("param1", "value of param1")); 

                UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(postParameters);         

                request.setEntity(formEntity);
                HttpResponse response = client.execute(request);

                String line;

                br = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
                while ((line = br.readLine()) != null)
                {
                    sb.append(line + "
");
                }
                br.close();

            } 
            catch(Exception e)
            {
                Toast.makeText(HttpPostActivity.this, "Exception: " + e.toString(), Toast.LENGTH_LONG).show();
            }
            finally 
            {
                if (br != null) 
                {
                    try 
                    {
                        br.close();
                    } 
                    catch(IOException ioe) 
                    {
                        ioe.printStackTrace();
                    }
                }           

            }           

            return(sb.toString());
        }


        protected void onPostExecute(String result) 
        {
            txtContent.setText(result);
        }

You need to implement onPostExecute as well . There are other APIS .

Android Async Task Documentation