Q:

How can I check whether a given phone number is saved in my contacts with little time consumption? 

I have some contact numbers saved in a remote server and I have more than 100 numbers saved on my Android phone. 
What I want to do is compare the numbers present on the remote server and the phone numbers in the Android phone and display only the matching numbers in a Listview i.e if 1234 is saved on my remote server and 1234, 5678,1000,etc are saved on my Android phone, then only the number 1234 should be displayed on the Listview.  
I have done the following coding and it works fine and gives me the result i want, but the problem is that the time consumption is very high. 
Can anyone suggest me whether it is possible to get the matching contacts without using a loop or is there any way to reduce the time consumption? 
My codes are as below, please guide me step by step. 
AsyncTask<Void, Void,Void> t = new AsyncTask<Void, Void,Void>()
{

    @Override
    protected Void doInBackground(Void... arg0) {
        String phoneNumber = null;
        //String email = null;
        Uri CONTENT_URI = ContactsContract. Contacts. CONTENT_URI;
        String _ID = ContactsContract. Contacts._ID;
        String DISPLAY_NAME = ContactsContract. Contacts. DISPLAY_NAME;
        String HAS_PHONE_NUMBER = ContactsContract. Contacts. HAS_PHONE_NUMBER;
        Uri PhoneCONTENT_URI = ContactsContract. CommonDataKinds. Phone. CONTENT_URI;
        String Phone_CONTACT_ID = ContactsContract. CommonDataKinds. Phone. CONTACT_ID;
        String NUMBER = ContactsContract. CommonDataKinds. Phone. NUMBER;

        StringBuffer output = new StringBuffer();
        if(getActivity()!=null)
        {
            ContentResolver contentResolver =getActivity().getApplicationContext().getContentResolver();
            //contentResolver=getActivity().getContentResolver().getContentResolver();
            Cursor cursor = contentResolver.query(CONTENT_URI, null,null, null, null);
            if (cursor.getCount() > 0) {
                while (cursor.moveToNext()) {
                    String contact_id = cursor.getString(cursor.getColumnIndex( _ID ));
                    String name = cursor.getString(cursor.getColumnIndex( DISPLAY_NAME ));
                    int hasPhoneNumber = Integer.parseInt(cursor.getString(cursor.getColumnIndex( HAS_PHONE_NUMBER )));
                    output.append("\n First Name:" + name);
                    Cursor phoneCursor = contentResolver.query(PhoneCONTENT_URI, null, Phone_CONTACT_ID + " = ?",  new String[] { contact_id }, null);
                    while (phoneCursor.moveToNext()) {
                        phoneNumber = phoneCursor.getString(phoneCursor.getColumnIndex(NUMBER));
                        String p=phoneNumber;
                        output.append("\n Phone number:" + phoneNumber);
                        String result = null;
                        InputStream is = null;
                        try{
                            HttpClient httpclient = new DefaultHttpClient();
                            HttpPost httppost = new HttpPost("http://10.0.2.2:80/contactcheck.php");

                            HttpResponse response1 = httpclient.execute(httppost);
                            HttpEntity entity = response1.getEntity();
                            is = entity.getContent();
                            Log.e("log_tag", "connection success ");
                        }
                        catch(Exception e)
                        {
                            Log.e("log_tag", "Error in http connection "+e.toString());
                        }
                        try
                        {
                            BufferedReader reader = new BufferedReader(new InputStreamReader(is,HTTP.UTF_8),8);
                            StringBuilder sb = new StringBuilder();
                            String line = null;
                            while ((line = reader.readLine()) ! = null)
                            {
                                sb.append(line + "\n");
                            }
                            is.close();
                            result=sb.toString();
                        }
                        catch(Exception e)
                        {
                            Log.e("log_tag", "Error converting result "+e.toString());
                        }
                        try
                        {
                            JSONArray jArray = new JSONArray(result);
                            String s11,s12,s13;
                            Log.w("Lengh",""+jArray.length());
                            for(int i=0;i<jArray.length();i++)
                            {
                                JSONObject json_data = jArray.getJSONObject(i);
                                s11=json_data.getString("PhoneId");
                                s12=json_data.getString("path");
                                s13=json_data.getString("UserId");
                                Log.w("matched",""+s11+p);
                                Log.i("path from json",""+s12);

                                if(p.compareTo(s11)==0){
                                    int count=0;
                                    count=db.getcountoffriends(s11);
                                    if(count==0)
                                    {
                                        queryValues.put("c",s11);
                                        queryValues.put("name",name);
                                        queryValues.put("path", s12);
                                        queryValues.put("fbid",s13);

                                        db.insertcontact(queryValues);
                                        imageload(s12,s13,s11);

                                    }

                                    Log.i("imageupload strings",""+s12+""+s13+""+s11);
                                }
                            }
                        }
                        catch(JSONException e)
                        {
                            Log.e("log_tag", "Error parsing data "+e.toString());
                        }
                    }
                }
            }
        }
        return null;
    }
};
t.execute();

A:

Take each phone number from remote server and pass to the following method:
public boolean contactExists(Context context, String number) {
    /// number is the phone number
    Uri lookupUri = Uri.withAppendedPath(
    PhoneLookup. CONTENT_FILTER_URI, 
    Uri.encode(number));
    String[] mPhoneNumberProjection = { PhoneLookup._ID, PhoneLookup. NUMBER, PhoneLookup. DISPLAY_NAME };
    Cursor cur = context.getContentResolver().query(lookupUri,mPhoneNumberProjection, null, null, null);
    try {
        if (cur.moveToFirst()) {
            return true;
        }
    } finally {
    if (cur ! = null)
        cur.close();
    } 
    return false;
 }

If the method returns true, store the relevant data to display in ListView
Original answer Android : Check phone number present in Contact List ? ( Phone number retrieve from phone call)

