phan 05 network

Pht trin ng dng Smartphone

Ti liu lu hnh ni b

y l ti liu tham kho s dng trong mn hc Lp trnh ng dng Smartphone Android

c tng hp, bin son t nhiu ngun bi cc thnh vin ca Nhm nghin cu v ng dng cng

ngh A106-i hc Hoa Sen.

Nhm A106-http://profiles.hoasen.edu.vn/groups/584/

Pht trin ng dng Smartphone Android

Pht trin ng

dng Smartphone

Phn 05: Network & Telephony L c Huy

Email: [email protected]


1 HTTP

Chc nng ca HTTP nh l mt giao thc kiu gi yu cu-nhn hi p trong m hnh in

ton my ch-my khch. Trn HTTP, mt trnh duyt web (Firefox, Internet Explorer, Chrome) s

ng vai tr nh mt ngi khch, trong khi ng dng chy trn my ch (my trung tm) s ng vai

tr nh l mt my ch. Ngi khash y s gi mt yu cu HTTP (HTTP request) ln my ch.

My ch, ni lu tr mt ngun ti nguyn no (Hnh nh, m thanh) s thay mt my khch thc

thi mt chc nng no l tr v mt hi p cho my khch. Hi p ny s bao gm thng tin trng

thi v yu cu c gi i cng vi ni dung c yu cu bi my khch trong n. Giao thc HTTP

c th hin qua hnh sau:

Trong m hnh trn tn ti hai i tng chnh: Client v Server. Trong ng dn kt ni

hai i tng chnh ca m hnh l giao thc HTTP. i tng Client s gi mt Request n my

Server yu cu thc thi mt tc v hoc ly mt d liu no . i tng Request cha cc tham s

xc nh a ch n c gi n cng vi cc tham s khc xc nh tc v cn thc thi cng nh

loi d liu cn ly. Cc tham s ny c th thuc hai loi: POST v GET. Tham s thuc loi GET s

nm trong ng dn a ch m i tng Request ang nm gi, tham s loi POST s khng nm

trong ng dn a ch.

VD: Gi i request c a ch sau: http://www.google.com.vn/search?q=leduchuy. y l mt

request dng GET. Ta c th thy trn a ch trn c mt tham s q=leduchuy xc nh t kha yu

cu my ch Google tm kim t kha: leduchuy.

My Server s phn tch i tng Request tm ra yu cu ca my Client s l v tr v d

liu trong i tng Response. My Client s phn tch i tng Response c tr v ly cc

thng tin cn thit. y l cch m giao thc HTTP hot ng.

Vic s dng giao thc HTTP trn Android hin nhin cng tun theo cch trn vi cc bc

nh sau:


1.1 S dng HTTP vi GET Request

1. Khi to mt i tng HttpClient.

2. Khi to mt phng thc HTTP: PostMethod hoc GetMethod.

3. Thit lp tham s cho phng thc HTTP.

4. Thc thi HTTP request bng cch s dng HttpClient.

5. Thao tao trn i tng Response c tr v.

nh ngha mt class java nh sau:

package niit.android;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.net.URI;

import org.apache.http.HttpResponse;

import org.apache.http.client.HttpClient;

import org.apache.http.client.methods.HttpGet;

import org.apache.http.impl.client.DefaultHttpClient;

public class NetworkManager {

public String executeHttpGet(String uri) throws Exception

{

BufferedReader in = null;

String result = "";

try {

HttpClient client = new DefaultHttpClient();

HttpGet request = new HttpGet();

request.setURI(new URI(uri));

HttpResponse response = client.execute(request);

in = new BufferedReader(new

InputStreamReader(response.getEntity().getContent()));

StringBuffer sb = new StringBuffer("");

String line = "";

String NL = System.getProperty("line.separator");

while ((line = in.readLine())!=null) {

sb.append(line + NL);

}

in.close();

Pht trin ng dng Smartphone Android result = sb.toString();

} finally {

if (in != null) {

try {

in.close();

} catch (IOException e) {

e.printStackTrace();

}

}

}

return result;

}

}

Trong :

HttpClient i din cho my Client trong m hnh trn. Mt i tng HttpClient ng gi

nhng tt c cc i tng cn thit thc thi mt HTTP request (a ch gi i, cc tham s i km).

y cng l i tng s l cookie, chng thc ti khon, qun l kt ni cng nh cc tnh nng khc

ca giao thc HTTP.

S dng lnh: request.setURI(new URI("http://code.google.com/android/")); gn a ch

s gi ng tng request i.

Lnh HttpResponse response = client.execute(request); s thc thi mt HTTP request v tr

v mt i tng Response.

Lnh response.getEntity() s tr v mt i tng HttpEntity. y l i tng cha cc th

HTML (HTML entity) c tr v t server.

Lnh getContent() s tr v mt i tng kiu InputStream. y l mt i tng i din

cho mt lung (stream) ni n khi d liu c tr v cha trong response. N s c dng c

d liu t khi d liu ny.

Tin hnh khi to mt i tng InputStreamReader bng lnh new InputStreamReader()

to thnh mt b c t lung mi to trn.

Tin hnh to mt BufferedReader bng lnh new BufferedReader() to thnh mt b c c

h tr b m (buffer) tng tc vic c d liu t lun k trn.

Tin hnh dng mt i tng String t d liu nhn v sau khi thc thi mt HTTP request.

Thc t th i tng String ny chnh l chui cha ni dung HTML c tr v. Vic dng i tng

String da vo StringBuffer ( sb.append(line + NL)).

Lu : cho php ng dng kt ni Internet, ta cn b xung dng sau vo file

AndroidManifest.xml:


1.2 S dng HTTP vi POST Request

Cc bc lm vic vi giao thc HTTP cng vi mt request dng POST cng tng t nh

vi request dng GET. Ta tin hnh nh ngha mt class java c ni dung nh sau:


import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.net.URI;

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.HttpGet;

import org.apache.http.client.methods.HttpPost;

import org.apache.http.impl.client.DefaultHttpClient;

import org.apache.http.message.BasicNameValuePair;

public class NetworkManager {

public String executeHttpPost(String

uri,List postParameters) throws Exception {

BufferedReader in = null;

String result = "";

try {

HttpClient client = new DefaultHttpClient();

HttpPost request = new HttpPost(uri);

UrlEncodedFormEntity formEntity = new

UrlEncodedFormEntity(

postParameters);

request.setEntity(formEntity);

HttpResponse response =

client.execute(request);

in = new BufferedReader(new

InputStreamReader(response.getEntity()

.getContent()));

StringBuffer sb = new StringBuffer("");

Pht trin ng dng Smartphone Android String line = "";

String NL =

System.getProperty("line.separator");

while ((line = in.readLine()) != null) {

sb.append(line + NL);

}

in.close();

result = sb.toString();

} finally {

if (in != null) {

try {

in.close();

} catch (IOException e) {


}

}

}

return result;

}

}

Trong :

Ta nh ngha List postParameters = new ArrayList();

cha cc tham s gi i vi POST Request. Cc tham s ny l d liu dng thc thi cc hnh ng

trn my ch hoc cc tham s dng xc nh d liu tr v.

Dng lnh postParameters.add(new BasicNameValuePair("one", "valueGoesHere")); thm

cc tham s vo danh sch tham s nh ngha trn.

Tin hnh m ha s tham s trn gi km request: UrlEncodedFormEntity formEntity =

new UrlEncodedFormEntity(postParameters);

S dng class NetworkManager trn nh sau:

String resultGet="";

String resultPost="";

NetworkManager networkManager = new NetworkManager();

try {

resultGet =

networkManager.executeHttpGet("http://www.google.com.vn/search?q

=hoasen+university");

System.out.print(result);

} catch (Exception e) {



}

}

List postParameters = new

ArrayList();

postParameters.add(new BasicNameValuePair("q",

"hoasen+university"));

try {

resultPost = networkManager.executeHttpPost("www.abc.com",

postParameters);

System.out.print(result);

} catch (Exception e) {


}

2 Telephony

2.1 SMS

2.1.1 Gi tin nhn

To Project vi cc thng s:

Project name: TelephonyExample

Build target: Android 2.3.3.

Application name: Telephony Example

Package name: niit.android

Create Activity: main

ng dng c th gi/nhn tin nhn trn ng dng, ta cn b xung ng k trn file

AndroidManifest.xml bng cch b xung hai dng sau:

Chnh sa file main.xml vi ni dung nh sau:


c c giao din nh sau:


Thay i file main.java vi ni dung nh sau:


import android.app.Activity;

import android.app.PendingIntent;

import android.content.Intent;

import android.os.Bundle;

import android.telephony.SmsManager;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.Toast;

public class main extends Activity {

Button btnSendSMS;

EditText txtPhoneNo;

EditText txtMessage;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState)

{


super.onCreate(savedInstanceState);

setContentView(R.layout.main);

btnSendSMS = (Button) findViewById(R.id.btnSendSMS);

txtPhoneNo = (EditText) findViewById(R.id.txtPhoneNo);

txtMessage = (EditText) findViewById(R.id.txtMessage);

btnSendSMS.setOnClickListener(new

view.OnClickListener()

{

public void onClick(View v)

{

String phoneNo =

txtPhoneNo.getText().toString();

String message =

txtMessage.getText().toString();

if (phoneNo.length()>0 &&

message.length()>0)

sendSMS(phoneNo, message);

else

Toast.makeText(getBaseContext(),

"Please enter both phone number and

message.",

Toast.LENGTH_SHORT).show();

}

});

}

//---sends an SMS message to another device---

private void sendSMS(String phoneNumber, String message)

{

SmsManager sms = SmsManager.getDefault();

sms.sendTextMessage(phoneNumber, null, message, null,

null);

}

}

gi mt tin nhn SMS, ta s dng mt i tng kiu SmsManager. Tuy nhin, khng ging

nh cc class khc, ta khng tin hnh khi to mt i tng kiu ny; thay vo ta s gi phng

thc static tn getDefault() tr v i tng SmsManager mc nh ca thit b. Trong phng

thc phng thc sendTextMessage() s gi tin nhn SMS vi mt i tng kiu PendingIntent. i

tng PendingIntent ny dng xc nh i tng s gi sau ny. V d: Sau khi gi tin nhn, ta c

th s dng i tng PendingIntent hin th mt Activity. Trong trng hp trn, i tng

PendingIntent n gin l ch n activity gi tin nhn i, bng cch ny s khng c vic g sy ra

sau khi tin nhn c gi i. Ta thay i phng thc sendSMS vi ni dung nh sau:


{

Pht trin ng dng Smartphone Android PendingIntent sentIntent =

PendingIntent.getActivity(this, 0, new Intent(this,

SentActivity.class), 0);

PendingIntent deliveryIntent =

PendingIntent.getActivity(this, 0, new Intent(this,

DeliveryActivity.class), 0);


sms.sendTextMessage(phoneNumber, null, message,

sentIntent, deliveryIntent);

}

Trong ta to ra hai i tng PendingIntent bng cch gi phng thc getActivity().

Phng thc ny s tr v mt PendingIntent dng khi ng mt activity vi cc thng s ch nh

i km. Ta to hai i tng kiu PendingIntent dng khi ng hai activity, mt activity s c

m ra khi tin nhn SMS c gi i (SentActivity) v mt activity s c m ra khi tin nhn SMS

c chuyn giao thnh cng.

Nu bn mong mun theo di tin trnh gi tin nhn, bn c th s dng PendingIntent cng vi

hai BroadcastReceiver nh sau:


{

String SENT = "SMS_SENT";

String DELIVERED = "SMS_DELIVERED";

PendingIntent sentPI = PendingIntent.getBroadcast(this,

0,

new Intent(SENT), 0);

PendingIntent deliveredPI =

PendingIntent.getBroadcast(this, 0,

new Intent(DELIVERED), 0);

//---when the SMS has been sent---

registerReceiver(new BroadcastReceiver(){

@Override

public void onReceive(Context arg0, Intent arg1) {

switch (getResultCode())

{

case Activity.RESULT_OK:

Toast.makeText(getBaseContext(), "SMS

sent",


break;

case

SmsManager.RESULT_ERROR_GENERIC_FAILURE:

Pht trin ng dng Smartphone Android Toast.makeText(getBaseContext(),

"Generic failure",


break;

case SmsManager.RESULT_ERROR_NO_SERVICE:

Toast.makeText(getBaseContext(), "No

service",


break;

case SmsManager.RESULT_ERROR_NULL_PDU:

Toast.makeText(getBaseContext(), "Null

PDU",


break;

case SmsManager.RESULT_ERROR_RADIO_OFF:

Toast.makeText(getBaseContext(), "Radio

off",


break;

}

}

}, new IntentFilter(SENT));

//---when the SMS has been delivered---

registerReceiver(new BroadcastReceiver(){

@Override

public void onReceive(Context arg0, Intent arg1) {

switch (getResultCode())

{

case Activity.RESULT_OK:


delivered",


break;

case Activity.RESULT_CANCELED:


not delivered",


break;

}

}

}, new IntentFilter(DELIVERED));


sms.sendTextMessage(phoneNumber, null, message, sentPI,

deliveredPI);

}

Pht trin ng dng Smartphone Android Trong phn code trn ta dng mt i tng PendingIntent (sendPI) theo di qu trnh gi

d tin nhn. Khi mt tin nhn SMS c gi i, phng thc onReceive ca BroadcastReceiver u

tin s c thc thi. Trong phng thc ny ta s tin hnh kim tra trng thi ca tin trnh gi tin

nhn. i tng PendingIntent th hai dng theo di qu trnh chuyn giao tin nhn. Phng thc

onReceive ca BroadcastReceiver th hai s c thc thi khi qu trnh chuyn giao mt tin nhn kt

thc. Ti y ta cng tin hnh kim tra trng thi ca vic chuyn giao tin nhn. Ta s dng phng

thc getBroadcast() to mt i tng PendingIntent dng khi ng mt Broadcast receiver.

i tng Intent c to trong trng hp ny c intent filter l String SENT =

"SMS_SENT"; v String DELIVERED = "SMS_DELIVERED";. Hai bin ny n gin l b lc dng

chn ng BroadcastReceiver m ta s nh ngha di.

Phng thc registerReceiver() dng ng k mt BroadcastRecevier s chy trn lung ca

activity hin ti. Phng thc ny s nhn vo hai tham s: tham s th nht chnh l i tng ci t

li interface BroadcastReceiver, tham s th hai l i tng Intent xc nh nhng Intent cng loi s

c dng khi ng BroadcastReceiver ny.

n y, kim tra s hot ng ca chng trnh ta cn hai my o Android c kh nng gi

nhn tin nhn vi nhau. lm c vic ny, trc tin ta cn m thm mt my o Android th hhai

bng cch m Window/Android SDK and AVD Manager trn Eclipse. To mt my o mi v nhn

Start khi ng my o mi to c kt qu nh sau:

Pht trin ng dng Smartphone Android gi tin nhn gia hai my o vi nhau ta thay s in thoi ngi nhn bng cch thay i

s in thoi ngi nhn bng Emulators port ca my o. Emulators port ca my o trn l 5556

hin th gc tri trn cng ca my o.

T my o u tin, s dng ng dng mi xy dng trn tin hnh gi tin nhn n my

o th hai kim th chng trnh.

2.1.2 Nhn tin nhn

Bn cnh vic gi tin nhn ta cn c th nh ngha mt BroadcastReceiver dng nhn tin

nhn c gi n thit b.

Tin hnh chnh sa file AndroidManifest.xml bng cch thm mt th receiver t c ni

dung nh sau:

Thm mt class SmsReceiver vi ni dung nh sau:

Pht trin ng dng Smartphone Android package niit.android;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;


import android.telephony.gsm.SmsMessage;


public class SmsReceiver extends BroadcastReceiver {

@Override

public void onReceive(Context context, Intent intent)

{

//---get the SMS message passed in---

Bundle bundle = intent.getExtras();

SmsMessage[] msgs = null;

String str = "";

if (bundle != null)

{

//---retrieve the SMS message received---

Object[] pdus = (Object[]) bundle.get("pdus");

msgs = new SmsMessage[pdus.length];

for (int i=0; i


B xung vo file AndroidManifest.xml ni dung nh sau:

To file SMSFolderExampleActivity.java vi ni dung:


import android.app.ListActivity;

import android.database.Cursor;

import android.net.Uri;


import android.widget.ListAdapter;

import android.widget.SimpleCursorAdapter;

public class SMSFolderExampleActitvity extends ListActivity {

private ListAdapter adapter;

private static final Uri SMS_INBOX =

Uri.parse("content://sms/inbox");

@Override

public void onCreate(Bundle bundle) {

super.onCreate(bundle);

Cursor c = getContentResolver().query(SMS_INBOX, null,

null, null, null);

startManagingCursor(c);

String[] columns = new String[] {"body"};

int[] names = new int[] { R.id.row };

adapter = new SimpleCursorAdapter(this,

R.layout.sms_folder, c, columns,

names);

setListAdapter(adapter);

}

}

Pht trin ng dng Smartphone Android Lnh Cursor c = getContentResolver().query(SMS_INBOX, null, null, null, null); s to ra mt

i tng con tr dng c tin nhn trong th mc inbox. Lnh startManagingCursor s bo cho

activity hin ti qun l vng i ca con tr va mi to ra (Khi activity thay i trng thi n cng

thay i trng thi ca con tr). Bng cch ny khi Activity b loi khi b nh n cng dn dp con tr

ny. Ngoi cch s dng SimpleCursorAdapter ta cn c th s dng con tr c d liu theo cch

sau:

result.moveToFirst();

while (!result.isAfterLast()) {

String address = result.getString(2);

String body =result.getString(11);

result.moveToNext();

}

Di y l danh sch cc th mc cha tin nhn SMS:

- All: content://sms/all

- Inbox: content://sms/inbox

- Sent: content://sms/sent

- Draft: content://sms/draft

- Outbox: content://sms/outbox

- Failed: content://sms/failed

- Queued: content://sms/queued

- Undelivered: content://sms/undelivered

- Conversations: content://sms/conversations

2.2 Gi email

Android khng h tr gi email trc tip t ng dng nn ta s phi to mt i tng Intent

khi ng ca s Activity dng gi mail nh sau:

Intent emailIntent=new Intent(Intent.ACTION_SEND);

String subject = "Hi!";

String body = "hello from android....";

String[] extra = new String[]{"[email protected]"};

emailIntent.putExtra(Intent.EXTRA_EMAIL, extra);

emailIntent.putExtra(Intent.EXTRA_SUBJECT, subject);

emailIntent.putExtra(Intent.EXTRA_TEXT, body);

emailIntent.setType("message/rfc822");


startActivity(emailIntent);

2.3 Lm vic vi Telephony maganager

Gi s ta vit mt ng dng chi nhc cho h iu hnh Android, khi ta cn bt c cc s

kin khi c cuc gi n ngng chi nhc. Hoc khi cuc in thoi kt thc ta cn tip tc chi

nhc. lm c vic ny ta c th s dng TelephonyManager c cung cp sn trong Android vi

cch thc nh sau:


import android.app.Activity;

import android.content.Context;


import android.telephony.PhoneStateListener;

import android.telephony.TelephonyManager;

import android.util.Log;


public class TelephonyServiceExampleActivity extends Activity{

private static final String TAG="TelephonyServiceDemo";

@Override

protected void onCreate(Bundle savedInstanceState)

{

super.onCreate(savedInstanceState);

TelephonyManager teleMgr =

(TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);

teleMgr.listen(new MyPhoneStateListener(),

PhoneStateListener.LISTEN_CALL_STATE);

}

class MyPhoneStateListener extends PhoneStateListener

{

@Override

public void onCallStateChanged(int state, String

incomingNumber) {

super.onCallStateChanged(state, incomingNumber);

Toast toast =

Toast.makeText(TelephonyServiceExampleActivity.this, "", 3000);

switch(state)

{

case TelephonyManager.CALL_STATE_IDLE:

Log.d(TAG, "call state idle...incoming

number is["+

Pht trin ng dng Smartphone Android incomingNumber+"]");break;

case TelephonyManager.CALL_STATE_RINGING:

Log.d(TAG, "call state ringing...incoming

number is["+

incomingNumber+"]");break;

case TelephonyManager.CALL_STATE_OFFHOOK:

Log.d(TAG, "call state Offhook...incoming

number is["+


default:

Log.d(TAG, "call state ["+state+"]incoming

number is["+


}

}

}

}

phan 05 network

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