Redes – Sabe o que são sockets de comunicação? (Parte III)

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;
 
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
 
public class SocketClient extends Activity {
 
EditText textOut;
TextView textIn,ip,porto;
 
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
 
textOut = (EditText)findViewById(R.id.textout);
ip = (EditText)findViewById(R.id.edtIP);
porto = (EditText)findViewById(R.id.edtPorto);
Button buttonSend = (Button)findViewById(R.id.send);
textIn = (TextView)findViewById(R.id.textin);
buttonSend.setOnClickListener(buttonSendOnClickListener);
}
 
Button.OnClickListener buttonSendOnClickListener
= new Button.OnClickListener(){
 
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
Socket socket = null;
DataOutputStream dataOutputStream = null;
DataInputStream dataInputStream = null;
 
try {
socket = new Socket(ip.getText().toString(), Integer.parseInt(porto.getText().toString()));
dataOutputStream = new DataOutputStream(socket.getOutputStream());
dataInputStream = new DataInputStream(socket.getInputStream());
dataOutputStream.writeUTF(textOut.getText().toString());
textIn.setText(dataInputStream.readUTF());
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
if (socket != null){
try {
socket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
 
if (dataOutputStream != null){
try {
dataOutputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
 
if (dataInputStream != null){
try {
dataInputStream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}};
}

<?xml version="1.0" encoding="utf-8"?>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
 
    <TextView
        android:id="@+id/textin"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
 
    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="IP Servidor"
        android:textAppearance="?android:attr/textAppearanceMedium" />
 
 
    <EditText
        android:id="@+id/edtIP"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:text="192.168.1.66" />
 
    <TextView
        android:id="@+id/textView3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Porto"
        android:textAppearance="?android:attr/textAppearanceMedium" />
 
    <EditText
        android:id="@+id/edtPorto"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:text="8888" />
 
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Mensagem"
        android:textAppearance="?android:attr/textAppearanceLarge" />
 
    <EditText
        android:id="@+id/textout"
        android:layout_width="fill_parent"
        android:layout_height="92dp"
        android:ems="10"
        android:inputType="text" >
 
        <requestFocus />
    </EditText>
 
    <Button
        android:id="@+id/send"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="enviar" />
 
</LinearLayout>

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