Client / Server Programming in Android

1. Client / Server Programmingin Android Eclipse IDE Android Development Tools (ADT) Android SDK http://www.vogella.com/articles/Android/article.html

2. TCP Echo Client (1)

3. Android Mobile Development • Install Eclipse IDE • Install Android Development Tools (ADT) • Install Android SDK • Install specific Android Versions through SDK Manager • Create / install an Android Virtual Device (AVD)

4. Android SDK / AVD Managers

5. Android SDK Manager

6. AVD Manager

7. From file menu, select “New” then “Project”

8. Identify project name

9. Identify the desired SDK (based on the target device)

10. Provide a unique package name (reverse Domain Name + project)

11. Empty Project Configuration

12. Main.xml – Graphical LayoutEmpty Project

13. Main.xml – Graphical LayoutCompleted Project

14. Main.xml

15. EchoClientActivity.xml

16. Strings.xml

17. AndroidManifest.xml

18. Base Android 2.2 Phone VD

19. Base Android 2.2 Phone VD

20. UDP Echo Client (1)

21. UDP Echo Client (2)

22. UDP Echo Client (3)

23. echoClient.apk

24. EchoClientActivity.java package edu.umkc.cotterr.echo; import android.app.Activity; android.os.Bundle; android.view.View; android.widget.EditText; android.widget.Toast; java.net.*; java.io.*; import edu.umkc.cotterr.echo.R; public class EchoClientActivity extends Activity { /** Called when the activity is first created. */ private EditText portNumber; private EditText hostName; private EditText inputMsg; private EditText resultMsg; private InetAddress ia; private Socket mySocket; private InputStream isIn; private PrintStream psOut; private byte abIn[];

25. EchoClientActivity.java public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); hostName = (EditText) findViewById(R.id.editText1); portNumber = (EditText) findViewById(R.id.editText2); resultMsg = (EditText) findViewById(R.id.editText3); inputMsg = (EditText) findViewById(R.id.editText4); }

26. EchoClientActivity.java public void myEchoHandler(View view) { switch (view.getId()) { case R.id.button1: /* This is the connect button String sHostName = hostName.getText().toString(); int iPortNumber = Integer.parseInt(portNumber.getText().toString()); try { ia = InetAddress.getByName(sHostName); mySocket = new Socket (ia, iPortNumber); Toast.makeText(this,"We are now connected to: " + hostName + "\n", Toast.LENGTH_LONG).show(); } catch (Exception ex) { Toast.makeText(this,"Connect to " + hostName + "failed. Exception" + ex + "\n", Toast.LENGTH_LONG).show(); } break;

27. EchoClientActivity.java case R.id.button2: /* This is the send data button */ String sResponse, sTemp String sInputMsg = inputMsg.getText().toString(); intiNumRead; abIn= new byte[1024]; try { isIn = mySocket.getInputStream(); psOut = new PrintStream(mySocket.getOutputStream()); psOut.print(sInputMsg); iNumRead = isIn.read(abIn,0,1024); sTemp = new String(abIn, 0, iNumRead); sResponse = "We got back: " + sTemp; resultMsg.setText(sResponse); } catch (Exception ex) { Toast.makeText(this,"Send data failed. Exception" + ex + "\n", Toast.LENGTH_LONG).show(); } break;

28. EchoClientActivity.java case R.id.button3: // This is the quit button. String sTemp2; try { mySocket.close(); inputMsg.setText(""); sTemp2 = new String ("Goodbye ..."); resultMsg.setText(sTemp2); } catch (Exception ex) { Toast.makeText(this,"Close socket failed. Exception“ + ex + "\n", Toast.LENGTH_LONG).show(); } } //end of switch } //end of myEchoHandler } //end of EchoClientActivity

29. R.java package edu.umkc.cotterr.echo; public final class R { public static final class attr { } public static final class color { public static final intbackgroundColor=0x7f050000; } public static final class drawable { public static final intic_launcher=0x7f020000; } public static final class layout { public static final int main=0x7f030000; }

30. R.java public static final class id { public static final int button1=0x7f060004; public static final int button2=0x7f060008; public static final int button3=0x7f060009; public static final int editText1=0x7f060001; public static final int editText2=0x7f060003; public static final int editText3=0x7f06000b; public static final int editText4=0x7f060006; public static final int linearLayout1=0x7f060007; public static final int textView1=0x7f060000; public static final int textView2=0x7f060002; public static final int textView3=0x7f060005; public static final int textView4=0x7f06000a; }

31. R.java public static final class string { public static final intConvertButton=0x7f040002; public static final intDefaultHost=0x7f040003; public static final intDefaultPort=0x7f040004; public static final intapp_name=0x7f040001; public static final intconnectButton=0x7f040007; public static final int hello=0x7f040000; public static final int hostname=0x7f040005; public static final int input=0x7f040008; public static final int port=0x7f040006; public static final int quit=0x7f04000b; public static final int result=0x7f040009; public static final int send=0x7f04000a; } }

32. main.xml <?xml version="1.0" encoding="utf-8"?> <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent“ android:layout_height="fill_parent" android:background="@color/backgroundColor" android:orientation="vertical" > <TextView android:id="@+id/textView1“ android:layout_width="wrap_content“ android:layout_height="wrap_content" android:text="@string/hostname" android:textAppearance="?android:attr/textAppearanceMedium" /> <EditText android:id="@+id/editText1“ android:layout_width="201dp" android:layout_height="wrap_content“ android:hint="@string/DefaultHost“ android:inputType="text" > <requestFocus /> </EditText>

33. main.xml <TextView android:id="@+id/textView2" android:layout_width="wrap_content“ android:layout_height="wrap_content" android:text="@string/port" android:textAppearance="?android:attr/textAppearanceMedium" /> <EditText android:id="@+id/editText2“ android:layout_width="73dp" android:layout_height="wrap_content" android:hint="@string/DefaultPort“ android:inputType="text" android:width="100dp" /> <Button android:id="@+id/button1" android:layout_width="wrap_content“ android:layout_height="wrap_content" android:onClick="myEchoHandler" android:text="@string/connectButton" />

34. main.xml <TextView android:id="@+id/textView3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/input" android:textAppearance="?android:attr/textAppearanceMedium" /> <EditText android:id="@+id/editText4" android:layout_width="match_parent" android:inputType="text" android:layout_height="wrap_content" />

35. main.xml <LinearLayout android:id="@+id/linearLayout1" android:layout_width="match_parent" android:layout_height="wrap_content" > <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="myEchoHandler" android:text="@string/send" /> <Button android:id="@+id/button3" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/quit" android:onClick="myEchoHandler"/> </LinearLayout>

36. main.xml <TextView android:id="@+id/textView4" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@string/result" android:textAppearance="?android:attr/textAppearanceLarge" /> <EditText android:id="@+id/editText3" android:layout_width="match_parent" android:layout_height="wrap_content" android:height="100dp" android:inputType="textMultiLine" /> </LinearLayout>

37. strings.xml <?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello">Hello World, EchoClientActivity!</string> <string name="app_name">Bob\'s EchoClient</string> <color name="backgroundColor">#002864</color> <string name="ConvertButton">Convert</string> <string name="DefaultHost">localhost</string> <string name="DefaultPort">3456</string> <string name="hostname">Hostname</string> <string name="port">Port</string> <string name="connectButton">Connect</string> <string name="input">User Input</string> <string name="result">Echo Results</string> <string name="send">Send Echo</string> <string name="quit">Exit Echo</string> </resources>

38. AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="edu.umkc.cotterr.echo" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="8" /> <uses-permission android:name="android.permission.INTERNET"/> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name" > <activity android:name=".EchoClientActivity" 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>

39. Summary • Android Development has strong support in Eclipse IDE • Core Android language is Java, with a full library of Android classes