Android Application to Send a File to Remote Server

This simple Android application sends a file to a remote server. In this example code server runs on local host. When the Send button is clicked the file is sent to the server.

Android Client Application

	<manifest android:versioncode="1" android:versionname="1.0" package="lakj.comspace.simpleclient"
	xmlns:android="http://schemas.android.com/apk/res/android">
	<uses-sdk android:minsdkversion="10">
	<uses-permission android:name="android.permission.INTERNET"></uses-permission>
	<application android:icon="@drawable/ic_launcher" android:label="@string/app_name">
	<activity android:label="@string/app_name" android:name=".SimpleClientActivity">
	<intent-filter>
	<action android:name="android.intent.action.MAIN">
	<category android:name="android.intent.category.LAUNCHER">
	</category>
	</action>
	</intent-filter>
	</activity>
	</application>
	</uses-sdk>
	</manifest>

view raw AndroidManifest.xml hosted with ❤ by GitHub

	<linearlayout android:layout_height="fill_parent" android:layout_width="fill_parent" android:orientation="vertical"
	xmlns:android="http://schemas.android.com/apk/res/android">
	<textview android:id="@+id/textView1" android:layout_height="wrap_content" android:layout_width="wrap_content"
	android:textappearance="?android:attr/textAppearanceLarge">
	<button android:id="@+id/button1" android:layout_gravity="center" android:layout_height="wrap_content"
	android:layout_width="wrap_content" android:text="Send">
	</button>
	</textview>
	</linearlayout>

view raw main.xml hosted with ❤ by GitHub

	/*
	* This is a simple Android mobile client
	* This application send any file to a remort server when the
	* send button is pressed
	* Author by Lak J Comspace
	*/
	package lakj.comspace.simpleclient;
	import java.io.BufferedInputStream;
	import java.io.File;
	import java.io.FileInputStream;
	import java.io.IOException;
	import java.io.OutputStream;
	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.TextView;
	public class SimpleClientActivity extends Activity {
	private Socket client;
	private FileInputStream fileInputStream;
	private BufferedInputStream bufferedInputStream;
	private OutputStream outputStream;
	private Button button;
	private TextView text;
	@Override
	public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.main);
	button = (Button) findViewById(R.id.button1); //reference to the send button
	text = (TextView) findViewById(R.id.textView1); //reference to the text view
	//Button press event listener
	button.setOnClickListener(new View.OnClickListener() {
	public void onClick(View v) {
	File file = new File("/mnt/sdcard/input.jpg"); //create file instance
	try {
	client = new Socket("10.0.2.2", 4444);
	byte[] mybytearray = new byte[(int) file.length()]; //create a byte array to file
	fileInputStream = new FileInputStream(file);
	bufferedInputStream = new BufferedInputStream(fileInputStream);
	bufferedInputStream.read(mybytearray, 0, mybytearray.length); //read the file
	outputStream = client.getOutputStream();
	outputStream.write(mybytearray, 0, mybytearray.length); //write file to the output stream byte by byte
	outputStream.flush();
	bufferedInputStream.close();
	outputStream.close();
	client.close();
	text.setText("File Sent");
	} catch (UnknownHostException e) {
	e.printStackTrace();
	} catch (IOException e) {
	e.printStackTrace();
	}
	}
	});
	}
	}

view raw SimpleClientActivity.java hosted with ❤ by GitHub

Server Application

	/*
	* This is a simple server application
	* This server receive a file from a Android client and save it in a given place.
	* Author by Lak J Comspace
	*/
	package simpleserver;
	import java.io.BufferedOutputStream;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.ServerSocket;
	import java.net.Socket;
	public class Main {
	private static ServerSocket serverSocket;
	private static Socket clientSocket;
	private static InputStream inputStream;
	private static FileOutputStream fileOutputStream;
	private static BufferedOutputStream bufferedOutputStream;
	private static int filesize = 10000000; // filesize temporary hardcoded
	private static int bytesRead;
	private static int current = 0;
	public static void main(String[] args) throws IOException {
	serverSocket = new ServerSocket(4444); //Server socket
	System.out.println("Server started. Listening to the port 4444");
	clientSocket = serverSocket.accept();
	byte[] mybytearray = new byte[filesize]; //create byte array to buffer the file
	inputStream = clientSocket.getInputStream();
	fileOutputStream = new FileOutputStream("D:\\output.jpg");
	bufferedOutputStream = new BufferedOutputStream(fileOutputStream);
	System.out.println("Receiving...");
	//following lines read the input slide file byte by byte
	bytesRead = inputStream.read(mybytearray, 0, mybytearray.length);
	current = bytesRead;
	do {
	bytesRead = inputStream.read(mybytearray, current, (mybytearray.length - current));
	if (bytesRead >= 0) {
	current += bytesRead;
	}
	} while (bytesRead > -1);
	bufferedOutputStream.write(mybytearray, 0, current);
	bufferedOutputStream.flush();
	bufferedOutputStream.close();
	inputStream.close();
	clientSocket.close();
	serverSocket.close();
	System.out.println("Sever recieved the file");
	}
	}

view raw main.java hosted with ❤ by GitHub

Simple Client-Server Application for Android

Note: Here is the updated tutorial of the following tutorial for the latest Android version:
http://lakjeewa.blogspot.com/2014/05/simple-android-client-server-application.html 
Following tutorial is based on Android 2.3 (API Level 10). It is not compatible with later versions since API Level 11 introduced AsyncTask implementation for network communication. Refer the above link instead for working solution. 

This application is a simple client-server application which has a Android mobile client and a Java server which is run on a machine. In this example, client is run on the Android emulator and the server is run on the local host. In Android 10.0.2.2 is the IP address for local host. This application allow to type a text message on a text field and when the Send button is press the message is sent to the server. Server continuously listen to the port. When there is a incoming message server read it and show it on the standard output.

Client Side Application

	<manifest android:versioncode="1" android:versionname="1.0" package="lakj.comspace.simpleclient"
	xmlns:android="http://schemas.android.com/apk/res/android">
	<uses-sdk android:minsdkversion="10">
	<uses-permission android:name="android.permission.INTERNET"></uses-permission>
	<application android:icon="@drawable/ic_launcher" android:label="@string/app_name">
	<activity android:label="@string/app_name" android:name=".SimpleClientActivity">
	<intent-filter>
	<action android:name="android.intent.action.MAIN">
	<category android:name="android.intent.category.LAUNCHER">
	</category>
	</action>
	</intent-filter>
	</activity>
	</application>
	</uses-sdk>
	</manifest>

view raw AndroidManifest.xml hosted with ❤ by GitHub

	<linearlayout android:layout_height="fill_parent" android:layout_width="fill_parent" android:orientation="vertical"
	xmlns:android="http://schemas.android.com/apk/res/android">
	<edittext android:id="@+id/editText1" android:inputtype="textMultiLine" android:layout_height="wrap_content"
	android:layout_width="match_parent">
	<requestfocus>
	</requestfocus>
	</edittext>
	<button android:id="@+id/button1" android:layout_gravity="center" android:layout_height="wrap_content"
	android:layout_width="wrap_content" android:text="Send">
	</button>
	</linearlayout>

view raw main.xml hosted with ❤ by GitHub

	/*
	* This is a simple Android mobile client
	* This application read any string messege typed on the text field and
	* send it to the server when the Send button is pressed
	* Author by Lak J Comspace
	*/
	package lakj.comspace.simpleclient;
	import java.io.IOException;
	import java.io.PrintWriter;
	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;
	public class SimpleClientActivity extends Activity {
	private Socket client;
	private PrintWriter printwriter;
	private EditText textField;
	private Button button;
	private String messsage;
	@Override
	public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.main);
	textField = (EditText) findViewById(R.id.editText1); //reference to the text field
	button = (Button) findViewById(R.id.button1); //reference to the send button
	//Button press event listener
	button.setOnClickListener(new View.OnClickListener() {
	public void onClick(View v) {
	messsage = textField.getText().toString(); //get the text message on the text field
	textField.setText(""); //Reset the text field to blank
	try {
	client = new Socket("10.0.2.2", 4444); //connect to server
	printwriter = new PrintWriter(client.getOutputStream(), true);
	printwriter.write(messsage); //write the message to output stream
	printwriter.flush();
	printwriter.close();
	client.close(); //closing the connection
	} catch (UnknownHostException e) {
	e.printStackTrace();
	} catch (IOException e) {
	e.printStackTrace();
	}
	}
	});
	}
	}

view raw SlimpleClientActivity.java hosted with ❤ by GitHub

Server Side Application

	/*
	* This is a simple server application
	* This server receive a string message from the Android mobile phone
	* and show it on the console.
	* Author by Lak J Comspace
	*/
	package simpleserver;
	import java.io.BufferedReader;
	import java.io.IOException;
	import java.io.InputStreamReader;
	import java.net.ServerSocket;
	import java.net.Socket;
	public class Main {
	private static ServerSocket serverSocket;
	private static Socket clientSocket;
	private static InputStreamReader inputStreamReader;
	private static BufferedReader bufferedReader;
	private static String message;
	public static void main(String[] args) {
	try {
	serverSocket = new ServerSocket(4444); //Server socket
	} catch (IOException e) {
	System.out.println("Could not listen on port: 4444");
	}
	System.out.println("Server started. Listening to the port 4444");
	while (true) {
	try {
	clientSocket = serverSocket.accept(); //accept the client connection
	inputStreamReader = new InputStreamReader(clientSocket.getInputStream());
	bufferedReader = new BufferedReader(inputStreamReader); //get the client message
	message = bufferedReader.readLine();
	System.out.println(message);
	inputStreamReader.close();
	clientSocket.close();
	} catch (IOException ex) {
	System.out.println("Problem in message reading");
	}
	}
	}
	}

view raw main.java hosted with ❤ by GitHub