Android POST请求未收到响应

Question

I am trying get a php request with a post method, and I have to change a textView . That textview is "t" in my MainActivity .

I should have the response string from my request but I am just having error as exception of the try catch in my httpHandler class below my MainActivity .

I have the idea that could the internet connection and not the Post method I am using, but I am not sure.

my MainActivity 

public class MainActivity extends Activity {

    EditText UsernameT;
    EditText PasswordT;
    httpHandler handler;
    public static TextView t;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        handler = new httpHandler();
        String txt = handler.post("http://www.gpspatronus.com:8080/app/applogin.php");
        t = (TextView) findViewById(R.id.text);

        t.setText(txt);

        /////////////////////////////////////////////////////////////////////////////////

        ////////////////////////////////////////////////////////////////////////////////////
        UsernameT = (EditText) findViewById(R.id.User);
        PasswordT = (EditText) findViewById(R.id.Pass);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    public void LogIn(View view) {

    }


}

and my POST class

import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

public class httpHandler {

    public String post(String posturl) {

        try {

            HttpClient httpclient = new DefaultHttpClient();
            /*Creamos el objeto de HttpClient que nos permitira conectarnos mediante peticiones   
            http*/
            HttpPost httppost = new HttpPost(posturl);
            /*El objeto HttpPost permite que enviemos una peticion de tipo POST a una URL          
            especificada*/
            //AÑADIR PARAMETROS
            List<NameValuePair> params = new ArrayList<NameValuePair>(2);
            params.add(new BasicNameValuePair("email", "email"));
            params.add(new BasicNameValuePair("password", "password"));

            /*Una vez añadidos los parametros actualizamos la entidad de httppost, esto       
            quiere decir en pocas palabras anexamos los parametros al objeto para que al enviarse     
            al        servidor envien los datos que hemos añadido*/
            httppost.setEntity(new UrlEncodedFormEntity(params));

            /*Finalmente ejecutamos enviando la info al server*/
            HttpResponse resp = httpclient.execute(httppost);
            String text = EntityUtils.toString(resp.getEntity());

            return text;

        } catch (Exception e) {
            return "error";
        }

    }


}

and finally my manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.patronusgps"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="19" />

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="com.example.patronusgps.MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

</manifest>

Answer 1

you can't perform http requests in UI thread. Search "NetworkOnMainThreadException" for more details. You must use AsynkTask.

Answer 2

use this code further queries,how to use asyntask and how to handle response everything i have specified here

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.json.JSONException;
import org.json.JSONObject;

import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity
{
    public EditText uname,pwd;
    Button btnlog1;
    TextView invalid;
    public Button btncancel1;
    public String db_select;
     String mUname;
     String mPwd;
    String temp;
    Intent intObj;
    Intent intent = null;

Boolean isInternetPresent = false;
    ConnectionDetector cd;
    private final String SERVICE_URL = "http://www.gpspatronus.com:8080/app/applogin.php";
    private final String TAG = "MainActivity";
    public static final String PREFS_NAME = "MyPrefsFile";
    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        MainActivity.this.setContentView(R.layout.activity_main);
        uname=(EditText)findViewById(R.id.editText1);
        pwd=(EditText)findViewById(R.id.editText2);
        invalid=(TextView)findViewById(R.id.textView3);
        btnlog1=(Button)findViewById(R.id.button1);
        //btncancel1=(Button)findViewById(R.id.button2);
        //SERVICE_URL=ServerURL.URL+"/msd";

        btnlog1.setOnClickListener(new View.OnClickListener()
        {           
            @Override
            public void onClick(View v) 
            {
                mUname=uname.getText().toString();
                mPwd=pwd.getText().toString();
                SharedPreferences prefs = getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
                SharedPreferences.Editor editor = prefs.edit();
                editor.putString("EMP_ID",mUname);
                editor.putString("EMP_PWD", mPwd);
                editor.commit(); //important, otherwise it wouldn't save.
//                  display("Login clicked");
                if(!mUname.equalsIgnoreCase("") && !mPwd.equalsIgnoreCase(""))
                {
                    cd = new ConnectionDetector(getApplicationContext());
                    isInternetPresent = cd.isConnectingToInternet();
                    //Toast.makeText(MainActivity.this, isInternetPresent, Toast.LENGTH_LONG).show();
                    if(isInternetPresent)
                    {


                    try
                    {
                        validat_user(mUname,mPwd);

                    }
                    catch(Exception e)
                    {
                        display("Network error.\nPlease check with your network settings.");
                        uname.setText("");
                        pwd.setText("");
                    }
                    }
                    else
                    {
                        display("No Internet Connection...");
                    }

                }
                else
                {
                    invalid.setText("Please enter the data");
                }
            }
        });

    }
    public void display(String msg) 
    {
        Toast.makeText(MainActivity.this, msg, Toast.LENGTH_LONG).show();
    }


    private void validat_user(String stg1, String stg2)
    {
        db_select=stg1;
        WebServiceTask wst = new WebServiceTask(WebServiceTask.POST_TASK, this, "Login in progress...");

        wst.addNameValuePair("EMP_ID", stg1);
        wst.addNameValuePair("EMP_PWD", stg2);

        wst.execute(new String[] { SERVICE_URL });

    }
    @SuppressWarnings("deprecation")
    public void no_net()
    {
        display( "No Network Connection");
        final AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create();
        alertDialog.setTitle("No Internet Connection");
        alertDialog.setMessage("You don't have internet connection.\nElse please check the Internet Connection Settings.");
        //alertDialog.setIcon(R.drawable.error_info);
        alertDialog.setCancelable(false);
        alertDialog.setButton("Close", new DialogInterface.OnClickListener() 
        {
            public void onClick(DialogInterface dialog, int which)
            {   
                alertDialog.cancel();
                MainActivity.this.finish();
                System.exit(0);
            }
        });
        alertDialog.setButton2("Use Local DataBase", new DialogInterface.OnClickListener() 
        {
            public void onClick(DialogInterface dialog, int which)
            {
                display( "Accessing local DataBase.....");
                alertDialog.cancel();
            }
        });
        alertDialog.show();
    }

    private class WebServiceTask extends AsyncTask<String, Integer, String> {

        public static final int POST_TASK = 1;

        private static final String TAG = "WebServiceTask";

        // connection timeout, in milliseconds (waiting to connect)
        private static final int CONN_TIMEOUT =12000;

        // socket timeout, in milliseconds (waiting for data)
        private static final int SOCKET_TIMEOUT =12000;

        private int taskType = POST_TASK;
        private Context mContext = null;
        private String processMessage = "Processing...";

        private ArrayList<NameValuePair> params = new ArrayList<NameValuePair>();

        private ProgressDialog pDlg = null;

        public WebServiceTask(int taskType, Context mContext, String processMessage) {

            this.taskType = taskType;
            this.mContext = mContext;
            this.processMessage = processMessage;
        }

        public void addNameValuePair(String name, String value) {

            params.add(new BasicNameValuePair(name, value));
        }

        @SuppressWarnings("deprecation")
        private void showProgressDialog() {

            pDlg = new ProgressDialog(mContext);
            pDlg.setMessage(processMessage);
            pDlg.setProgressDrawable(mContext.getWallpaper());
            pDlg.setProgressStyle(ProgressDialog.STYLE_SPINNER);
            pDlg.setCancelable(false);
            pDlg.show();

        }

        @Override
        protected void onPreExecute() {

            showProgressDialog();

        }

        protected String doInBackground(String... urls) {

            String url = urls[0].toString();
            String result = "";
            HttpResponse response = doResponse(url);
            if (response == null) {
                return result;
            } else {

                try {

                    result = inputStreamToString(response.getEntity().getContent());

                } catch (IllegalStateException e) {
                    Log.e(TAG, e.getLocalizedMessage(), e);

                } catch (IOException e) {
                    Log.e(TAG, e.getLocalizedMessage(), e);
                }
                catch(Exception e)
                {
                    Log.e(TAG, e.getLocalizedMessage(), e);
                }

            }

            return result;
        }

        @Override
        protected void onPostExecute(String response) {

            handleResponse(response);
            pDlg.dismiss();

        }

        // Establish connection and socket (data retrieval) timeouts
        private HttpParams getHttpParams() {

            HttpParams htpp = new BasicHttpParams();

            HttpConnectionParams.setConnectionTimeout(htpp, CONN_TIMEOUT);
            HttpConnectionParams.setSoTimeout(htpp, SOCKET_TIMEOUT);

            return htpp;
        }

        private HttpResponse doResponse(String url) {

            // Use our connection and data timeouts as parameters for our
            // DefaultHttpClient
            HttpClient httpclient = new DefaultHttpClient(getHttpParams());

            HttpResponse response = null;

            try {
                switch (taskType) {

                case POST_TASK:

                    HttpPost httppost= new HttpPost(url);
                    httppost.setEntity(new UrlEncodedFormEntity(params));
                    response = httpclient.execute(httppost);

                    break;
                }
            } 
            catch (Exception e) {
            //  display("Remote DataBase can not be connected.\nPlease check network connection.");

                Log.e(TAG, e.getLocalizedMessage(), e);
                return null;

            }

            return response;
        }

        private String inputStreamToString(InputStream is) {

            String line = "";
            StringBuilder total = new StringBuilder();

            // Wrap a BufferedReader around the InputStream
            BufferedReader rd = new BufferedReader(new InputStreamReader(is));

            try {
                // Read response until the end
                while ((line = rd.readLine()) != null) {
                    total.append(line);
                }
            } catch (IOException e) {
                Log.e(TAG, e.getLocalizedMessage(), e);
            }
            catch(Exception e)
            {
                Log.e(TAG, e.getLocalizedMessage(), e);
            }

            // Return full string
            return total.toString();
        }

    }
    public void handleResponse(String response) 

    {    
    //display("Response:"+response);
        if(!response.equalsIgnoreCase(""))
        {
            JSONObject jso;
            try {
                jso = new JSONObject(response);


                    String status = jso.getString("status");
                    int valid=jso.getInt("valid");
              //     display("Welcome : "+UName);
                 if(valid>0)
                 {
                    if( status.equalsIgnoreCase("") || status==null ||  status.equalsIgnoreCase("Failed"))
                    {
                        invalid.setText("Invalid password");
                        //reset();
                        pwd.setText("");
                    }
                    else
                    {
                        //display(status);
                        intObj=new Intent(MainActivity.this,Design_Activity.class);
                        startActivity(intObj);
                        MainActivity.this.finish();     
                    }

                 }
                 else
                 {
                     invalid.setText("Invalid userid");
                     uname.setText("");
                 }
                }
            catch (JSONException e1) {

                Log.e(TAG, e1.getLocalizedMessage(), e1);
            }
            catch(Exception e)
            {
                Log.e(TAG, e.getLocalizedMessage(), e);
            }


        }
        else
        {
            display("Could not able to reach Server!");
        }


    }
    public void reset()
    {


        pwd.setText("");
        uname.setText("");
    }

}