I have a TCP client and a TCP server class in my app. The client sends small strings such as "1|2|" or "1|11|"
Client class
public class TcpClient {
private static final int MAX_DATA_RETRY = 1;
private static final int PING_TIMEOUT = 100;
private ClientThread thread;
private boolean mRun = true;
private PrintWriter mBufferOut;
private String mIPAdress;
private ArrayList<BufferDataItem> messageBuffer = new ArrayList<BufferDataItem>();
private Socket mSocket;
public TcpClient()
{
thread = new ClientThread();
thread.start();
}
private class ClientThread extends Thread {
@Override
public void run() {
while(mRun)
{
if(messageBuffer.size() <= 0)
continue;
BufferDataItem currMessage = messageBuffer.get(0);
currMessage.retryCount++;
if(currMessage.retryCount > MAX_DATA_RETRY)
{
messageBuffer.remove(0);
continue;
}
try {
//here you must put your computer's IP address.
InetAddress serverAddr = InetAddress.getByName(currMessage.ip);
//Log.e("TCP Client", "C: Connecting...");
try {
if(!serverAddr.isReachable(PING_TIMEOUT))
{
//only attempt to connect to devices that are reachable
messageBuffer.remove(0);
continue;
}
//create a socket to make the connection with the server
mSocket = new Socket(serverAddr, TcpManager.SERVER_PORT);
//Log.i("TCP Debug", "inside try catch");
//sends the message to the server
mBufferOut = new PrintWriter(new BufferedWriter(new OutputStreamWriter(mSocket.getOutputStream())), true);
String message = currMessage.message;
if (mBufferOut != null && !mBufferOut.checkError()) {
Log.d("TCP SEND", "PUTTING IN BUFFER! " + message);
mBufferOut.println(message);
listener.messageSent(message, currMessage.ip);
messageBuffer.remove(0);
}
mBufferOut.flush();
}
catch (ConnectException e) {
//Connection refused by found device!
//Log.e("TCP", "C: ConnectException ip = "+currMessage.ip, e);
listener.hostUnreachable(currMessage.ip);
continue;
}
catch (Exception e) {
Log.e("TCP", "S: Error", e);
listener.messageSendError(e);
}
finally {
if(mSocket != null)
mSocket.close();
}
}
catch (Exception e) {
Log.e("TCP", "C: Error", e);
listener.messageSendError(e);
continue;
}
}
}
}
/**
* Sends the message entered by client to the server
*
* @param message text entered by client
*/
public void sendMessage(String message) {
BufferDataItem data = new BufferDataItem();
data.message = message;
data.ip = mIPAdress;
messageBuffer.add(data);
}
public void sendMessage(String message, String ip) {
mIPAdress = ip;
BufferDataItem data = new BufferDataItem();
data.message = message;
data.ip = mIPAdress;
messageBuffer.add(data);
}
/**
* Close the connection and release the members
*/
public void stopClient() {
Log.i("Debug", "stopClient");
mRun = false;
if (mBufferOut != null) {
mBufferOut.flush();
mBufferOut.close();
}
mBufferOut = null;
}
private class BufferDataItem
{
public String message = "";
public int retryCount = 0;
public String ip = "";
}
private OnMessageSent listener = null;
public interface OnMessageSent {
public void messageSent(String message, String ip);
public void hostUnreachable(String ip);
public void messageSendError(Exception e);
}
public void setMessageSentListener(OnMessageSent listener)
{
this.listener = listener;
}
public void removeMessageSentListener()
{
this.listener = null;
}
}
Server Class
public class TcpServer {
private ServerThread thread;
private boolean mRun = true;
private boolean mEnd = false;
public TcpServer()
{
thread = new ServerThread();
thread.start();
}
private class ServerThread extends Thread {
@Override
public void run() {
try {
Boolean end = false;
ServerSocket ss = new ServerSocket(TcpManager.SERVER_PORT);
while (mRun) {
//Server is waiting for client here, if needed
Socket s = ss.accept();
BufferedReader input = new BufferedReader(new InputStreamReader(s.getInputStream()));
//PrintWriter output = new PrintWriter(s.getOutputStream(), true); //Autoflush
String st = input.readLine();
String remoteIP = s.getRemoteSocketAddress().toString();
int index = remoteIP.indexOf(":");
remoteIP = remoteIP.substring(1,index);
Log.d("TCP READ", "TCP READ: " + st);
if(st != null)
listener.messageReceived(st, remoteIP);
//output.println("Good bye and thanks for all the fish :)");
if(mEnd)
{
s.close();
mRun = false;
}
}
ss.close();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
//Declare the interface. The method messageReceived(String message) will must be implemented in the MyActivity
//class at on asynckTask doInBackground
public interface OnMessageReceived {
public void messageReceived(String message, String ip);
}
private OnMessageReceived listener = null;
public void SetMessageReceivedListener(OnMessageReceived listener)
{
this.listener = listener;
}
public void RemoveMessageReceivedListener()
{
this.listener = null;
}
}
This works fine for the first few times it runs and then but then the Client sends "1|11|" and the the server sets st as null during the readLine. String st = input.readLine();
Does anyone have any suggestions?
