Develop Reference

how to init snmp V3 Parameters to get snmpV3 trap using AdventNet

I am trying to recieve SNMP v3 traps from a device, using Adventnet.
When getting a trap I see the following AdventNet exception thrown:
Exception while constructing message after receiving PDU. Dropping this PDU received from xxx.xxx.xxx.xxx. com.adventnet.snmp.snmp2.SnmpException: Parse Header: Incorrect Scoped data
If I monitor the traps using NG-Soft browser the traps are recieved correctly.
Here is my code:
private void initV3Parameters(NEData neData) throws InterruptedException
{
logger.debug("in.");
try
{
logger.debug(".in");
SnmpAPI m_api = new SnmpAPI();
m_api.setDebug( true );
SnmpSession m_session = new SnmpSession(m_api);
m_session.addSnmpClient(this);
UDPProtocolOptions m_udpOpt = new UDPProtocolOptions();
m_udpOpt.setRemoteHost(neData.m_szIpAddress);
m_session.setProtocolOptions(m_udpOpt);
try
{
m_session.open();
String message="Succes to bind port: "+session.getLocalPort();
logger.info(message);
System.out.println(message);
}
catch (Exception ex)
{
String message = "Failed to open session - Port in use or permission denied. \n Message- "+ ex.getMessage() + "\n Will exit from Trap process. ";
logger.error(message, ex);
System.err.println(message);
throw new RuntimeException(message);
}
SnmpEngineEntry engineentry = new SnmpEngineEntry(neData.m_szIpAddress, m_udpOpt.getRemotePort());
SnmpEngineTable enginetable = m_api.getSnmpEngine();
enginetable.addEntry(engineentry);
try
{
engineentry.discoverSnmpEngineID(m_session,10000,3);
}
catch (Exception e)
{
logger.error("Failed to discover snmp EngineID. " + e.getMessage());
printToLog("failed",neData);
return;
}
USMUserEntry entry = new USMUserEntry(neData.usmUser.getBytes(), engineentry.getEngineID());
entry.setAuthProtocol(Integer.parseInt(neData.authProtocol));
entry.setAuthPassword(neData.authPassword.getBytes());
entry.setPrivProtocol(Integer.parseInt(neData.privProtocol));
entry.setPrivPassword(neData.privPassword.getBytes());
byte[] authKey = USMUtils.password_to_key(entry.getAuthProtocol(),
neData.authPassword.getBytes(),
neData.authPassword.getBytes().length,
engineentry.getEngineID());
entry.setAuthKey(authKey);
byte[] privKey = USMUtils.password_to_key(entry.getAuthProtocol(),
neData.privPassword.getBytes(),
neData.privPassword.getBytes().length,
engineentry.getEngineID());
entry.setPrivKey(privKey);
entry.setEngineEntry(engineentry);
entry.setSecurityLevel(Snmp3Message.AUTH_PRIV);
SecurityProvider provider = m_api.getSecurityProvider();
USMUserTable userTable = (USMUserTable) provider.getTable(3);
userTable.addEntry(entry);
entry.timeSynchronize(m_session, m_udpOpt);
printToLog("success",neData);
}
catch (Exception exp)
{
logger.error(exp.getMessage()+" for ip = "+neData.m_szIpAddress,exp);
discoveredDeque.put(neData);
printToLog("failed",neData);
}
}
I've also tried Using High-Level API
USMUtils.init_v3_parameters(
neData.usmUser,
null,
Integer.valueOf(neData.authProtocol),
neData.authPassword,
neData.privPassword,
udpOptions,
session,
false,
Integer.valueOf(neData.privProtocol));
In this case I see the trap using public void debugPrint (String debugOutput)
and no exception is throwing.
But there is nothing in the callback
Any advice will be welcome!!!

It turns out that there was a problem with the time synchronization of the device that sends the traps and my code worked perfectly fine.
probably NG-Soft doesn't care from time sync...
I attach my code here in case any of you will need it in the future...
private SnmpSession session;
/**
* Create a listener for trap version 1-2
*/
public void trapsListener ()
{
logger.debug(".in");
SnmpAPI api = new SnmpAPI();
// api.setDebug( true );
session = new SnmpSession(api);
session.addSnmpClient(this);
UDPProtocolOptions udpOpt = new UDPProtocolOptions();
udpOpt.setLocalPort(TRAP_PORT);
session.setProtocolOptions(udpOpt);
try
{
session.open();
String message="Succes to bind port: "+session.getLocalPort();
logger.info(message);
System.out.println(message);
}
catch (Exception ex)
{
String message = "Failed to open session - Port in use or permission denied. \n Message- "+ ex.getMessage() + "\n Will exit from Trap process. ";
logger.error(message, ex);
System.err.println(message);
throw new RuntimeException(message);
}
}
/**
* For each new device
* 1) discover the snmp engineID
* 2) create SnmpEngineEntry and add it to SnmpEngineTable
* 3) create USMUserEntry and add it to USMUserTable
* 4) performs time synchronization
**/
private void initV3Parameters(Device data) throws InterruptedException
{
logger.debug("in.");
try
{
UDPProtocolOptions udpOptions = new UDPProtocolOptions();
udpOptions.setLocalPort(TRAP_PORT);
udpOptions.setRemoteHost(data.getIpAddress());
USMUtils.init_v3_parameters(
data.getUsmUser(),
null,// null means that the SNMPv3 discovery will be activated
Integer.valueOf(data.getAuthProtocol()),
data.getAuthPassword(),
data.getPrivPassword(),
udpOptions,
session,
false,
Integer.valueOf(data.getPrivProtocol()));
printToLog("secsses",data);
}
catch (SnmpException exp) {
logger.error(exp.getMessage()+" for ip = "+data.getIpAddress(),exp);
printToLog("failed",data);
}
}

More conccurent users of Netty and BoneCP / Basic Socket Server

Disclaimer- I am not a Java programmer. Odds are I'll need to do my homework on any advice given, but I will gladly do so :)
That said, I wrote a complete database-backed socket server which is working just fine for my small tests, and now I'm getting ready for initial release. Since I do not know Java/Netty/BoneCP well- I have no idea if I made a fundamental mistake somewhere that will hurt my server before it even gets out the door.
For example, I have no idea what an executor group does exactly and what number I should use. Whether it's okay to implement BoneCP as a singleton, is it really necessary to have all those try/catch's for each database query? etc.
I've tried to reduce my entire server to a basic example which operates the same way as the real thing (I stripped this all in text, did not test in java itself, so excuse any syntax errors due to that).
The basic idea is that clients can connect, exchange messages with the server, disconnect other clients, and stay connected indefinitely until they choose or are forced to disconnect. (the client will send ping messages every minute to keep the connection alive)
The only major difference, besides untesting this example, is how the clientID is set (safely assume it is truly unique per connected client) and that there is some more business logic in checking of values etc.
Bottom line- can anything be done to improve this so it can handle the most concurrent users possible? Thanks!
//MAIN
public class MainServer {
public static void main(String[] args) {
EdgeController edgeController = new EdgeController();
edgeController.connect();
}
}
//EdgeController
public class EdgeController {
public void connect() throws Exception {
ServerBootstrap b = new ServerBootstrap();
ChannelFuture f;
try {
b.group(new NioEventLoopGroup(), new NioEventLoopGroup())
.channel(NioServerSocketChannel.class)
.localAddress(9100)
.childOption(ChannelOption.TCP_NODELAY, true)
.childOption(ChannelOption.SO_KEEPALIVE, true)
.childHandler(new EdgeInitializer(new DefaultEventExecutorGroup(10)));
// Start the server.
f = b.bind().sync();
// Wait until the server socket is closed.
f.channel().closeFuture().sync();
} finally { //Not quite sure how to get here yet... but no matter
// Shut down all event loops to terminate all threads.
b.shutdown();
}
}
}
//EdgeInitializer
public class EdgeInitializer extends ChannelInitializer<SocketChannel> {
private EventExecutorGroup executorGroup;
public EdgeInitializer(EventExecutorGroup _executorGroup) {
executorGroup = _executorGroup;
}
#Override
public void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast("idleStateHandler", new IdleStateHandler(200,0,0));
pipeline.addLast("idleStateEventHandler", new EdgeIdleHandler());
pipeline.addLast("framer", new DelimiterBasedFrameDecoder(8192, Delimiters.nulDelimiter()));
pipeline.addLast("decoder", new StringDecoder(CharsetUtil.UTF_8));
pipeline.addLast("encoder", new StringEncoder(CharsetUtil.UTF_8));
pipeline.addLast(this.executorGroup, "handler", new EdgeHandler());
}
}
//EdgeIdleHandler
public class EdgeIdleHandler extends ChannelHandlerAdapter {
private static final Logger logger = Logger.getLogger( EdgeIdleHandler.class.getName());
#Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception{
if(evt instanceof IdleStateEvent) {
ctx.close();
}
}
private void trace(String msg) {
logger.log(Level.INFO, msg);
}
}
//DBController
public enum DBController {
INSTANCE;
private BoneCP connectionPool = null;
private BoneCPConfig connectionPoolConfig = null;
public boolean setupPool() {
boolean ret = true;
try {
Class.forName("com.mysql.jdbc.Driver");
connectionPoolConfig = new BoneCPConfig();
connectionPoolConfig.setJdbcUrl("jdbc:mysql://" + DB_HOST + ":" + DB_PORT + "/" + DB_NAME);
connectionPoolConfig.setUsername(DB_USER);
connectionPoolConfig.setPassword(DB_PASS);
try {
connectionPool = new BoneCP(connectionPoolConfig);
} catch(SQLException ex) {
ret = false;
}
} catch(ClassNotFoundException ex) {
ret = false;
}
return(ret);
}
public Connection getConnection() {
Connection ret;
try {
ret = connectionPool.getConnection();
} catch(SQLException ex) {
ret = null;
}
return(ret);
}
}
//EdgeHandler
public class EdgeHandler extends ChannelInboundMessageHandlerAdapter<String> {
private final Charset CHARSET_UTF8 = Charset.forName("UTF-8");
private long clientID;
static final ChannelGroup channels = new DefaultChannelGroup();
#Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
Connection dbConnection = null;
Statement statement = null;
ResultSet resultSet = null;
String query;
Boolean okToPlay = false;
//Check if status for ID #1 is true
try {
query = "SELECT `Status` FROM `ServerTable` WHERE `ID` = 1";
dbConnection = DBController.INSTANCE.getConnection();
statement = dbConnection.createStatement();
resultSet = statement.executeQuery(query);
if (resultSet.first()) {
if (resultSet.getInt("Status") > 0) {
okToPlay = true;
}
}
} catch (SQLException ex) {
okToPlay = false;
} finally {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException logOrIgnore) {
}
}
if (statement != null) {
try {
statement.close();
} catch (SQLException logOrIgnore) {
}
}
if (dbConnection != null) {
try {
dbConnection.close();
} catch (SQLException logOrIgnore) {
}
}
}
if (okToPlay) {
//clientID = setClientID();
sendCommand(ctx, "HELLO", "WORLD");
} else {
sendErrorAndClose(ctx, "CLOSED");
}
}
#Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
channels.remove(ctx.channel());
}
#Override
public void messageReceived(ChannelHandlerContext ctx, String request) throws Exception {
// Generate and write a response.
String[] segments_whitespace;
String command, command_args;
if (request.length() > 0) {
segments_whitespace = request.split("\\s+");
if (segments_whitespace.length > 1) {
command = segments_whitespace[0];
command_args = segments_whitespace[1];
if (command.length() > 0 && command_args.length() > 0) {
switch (command) {
case "HOWDY": processHowdy(ctx, command_args); break;
default: break;
}
}
}
}
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
TraceUtils.severe("Unexpected exception from downstream - " + cause.toString());
ctx.close();
}
/* */
/* STATES - / CLIENT SETUP */
/* */
private void processHowdy(ChannelHandlerContext ctx, String howdyTo) {
Connection dbConnection = null;
Statement statement = null;
ResultSet resultSet = null;
String replyBack = null;
try {
dbConnection = DBController.INSTANCE.getConnection();
statement = dbConnection.createStatement();
resultSet = statement.executeQuery("SELECT `to` FROM `ServerTable` WHERE `To`='" + howdyTo + "'");
if (resultSet.first()) {
replyBack = "you!";
}
} catch (SQLException ex) {
} finally {
if (resultSet != null) {
try {
resultSet.close();
} catch (SQLException logOrIgnore) {
}
}
if (statement != null) {
try {
statement.close();
} catch (SQLException logOrIgnore) {
}
}
if (dbConnection != null) {
try {
dbConnection.close();
} catch (SQLException logOrIgnore) {
}
}
}
if (replyBack != null) {
sendCommand(ctx, "HOWDY", replyBack);
} else {
sendErrorAndClose(ctx, "ERROR");
}
}
private boolean closePeer(ChannelHandlerContext ctx, long peerClientID) {
boolean success = false;
ChannelFuture future;
for (Channel c : channels) {
if (c != ctx.channel()) {
if (c.pipeline().get(EdgeHandler.class).receiveClose(c, peerClientID)) {
success = true;
break;
}
}
}
return (success);
}
public boolean receiveClose(Channel thisChannel, long remoteClientID) {
ChannelFuture future;
boolean didclose = false;
long thisClientID = (clientID == null ? 0 : clientID);
if (remoteClientID == thisClientID) {
future = thisChannel.write("CLOSED BY PEER" + '\n');
future.addListener(ChannelFutureListener.CLOSE);
didclose = true;
}
return (didclose);
}
private ChannelFuture sendCommand(ChannelHandlerContext ctx, String cmd, String outgoingCommandArgs) {
return (ctx.write(cmd + " " + outgoingCommandArgs + '\n'));
}
private ChannelFuture sendErrorAndClose(ChannelHandlerContext ctx, String error_args) {
ChannelFuture future = sendCommand(ctx, "ERROR", error_args);
future.addListener(ChannelFutureListener.CLOSE);
return (future);
}
}

When a network message arrive at server, it will be decoded and will release a messageReceived event.
If you look at your pipeline, last added thing to pipeline is executor. Because of that executor will receive what has been decoded and will release the messageReceived event.
Executors are processor of events, server will tell which events happening through them. So how executors are being used is an important subject. If there is only one executor and because of that, all clients using this same executor, there will be a queue for usage of this same executor.
When there are many executors, processing time of events will decrease, because there will not be any waiting for free executors.
In your code
new DefaultEventExecutorGroup(10)
means this ServerBootstrap will use only 10 executors at all its lifetime.
While initializing new channels, same executor group being used:
pipeline.addLast(this.executorGroup, "handler", new EdgeHandler());
So each new client channel will use same executor group (10 executor threads).
That is efficient and enough if 10 threads are able to process incoming events properly. But if we can see messages are being decoded/encoded but not handled as events quickly, that means there is need to increase amount of them.
We can increase number of executors from 10 to 100 like that:
new DefaultEventExecutorGroup(100)
So that will process event queue faster if there is enough CPU power.
What should not be done is creating new executor for each new channel:
pipeline.addLast(new DefaultEventExecutorGroup(10), "handler", new EdgeHandler());
Above line is creating a new executor group for each new channel, that will slow down things greatly, for example if there are 3000 clients, there will be 3000 executorgroups(threads). That is removing main advantage of NIO, ability to use with low thread amounts.
Instead of creating 1 executor for each channel, we can create 3000 executors at startup and at least they will not be deleted and created each time a client connects/disconnects.
.childHandler(new EdgeInitializer(new DefaultEventExecutorGroup(3000)));
Above line is more acceptable than creating 1 executor for each client, because all clients are connected to same ExecutorGroup and when a client disconnects Executors still there even if client data is removed.
If we must speak about database requests, some database queries can take long time to being completed, so if there are 10 executorss and there are 10 jobs being processed, 11th job will have to wait until one of others complete. This is a bottleneck if server receiving more than 10 very time consuming database job at the same time. Increasing count of executors will solve bottleneck to some degree.

java.net.SocketException: Broken pipe smpp.logica library

why i got this error
20:43:40,798 ERROR Tx:809 - java.net.SocketException: Broken pipe
java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
at java.io.BufferedOutputStream.write(BufferedOutputStream.java:109)
at com.logica.smpp.TCPIPConnection.send(TCPIPConnection.java:353)
at com.logica.smpp.Transmitter.send(Transmitter.java:79)
at com.logica.smpp.Session.send(Session.java:993)
at com.logica.smpp.Session.send(Session.java:1048)
at com.logica.smpp.Session.enquireLink(Session.java:789)
at com.logica.smpp.Tx.kirimEnquireLink(Tx.java:795)
at com.logica.smpp.Tx.access$0(Tx.java:777)
at com.logica.smpp.Tx$1.run(Tx.java:120)
at java.util.TimerThread.mainLoop(Timer.java:512)
at java.util.TimerThread.run(Timer.java:462)
..I'm Using Open smpp logica library to create smsc client..for a few hours it's work but then the error come out..when i'm trying to send enquiry link,,the session I create is syncronize and the type of connection is Transceiver here's a piece of code i used to bind and to enqury link
private void bind()
{
debug.enter(this, "SMPPTest.bind()");
try {
if (bound) {
System.out.println("Already bound, unbind first.");
return;
}
BindRequest request = null;
BindResponse response = null;
String syncMode = (asynchronous ? "a" : "s");
// type of the session
syncMode = getParam("Asynchronous/Synchronnous Session? (a/s)",
syncMode);
if (syncMode.compareToIgnoreCase("a")==0) {
asynchronous = true;
} else if (syncMode.compareToIgnoreCase("s")==0) {
asynchronous = false;
} else {
System.out.println("Invalid mode async/sync, expected a or s, got "
+ syncMode +". Operation canceled.");
return;
}
// input values
bindOption = getParam("Transmitter/Receiver/Transciever (t/r/tr)",
bindOption);
if (bindOption.compareToIgnoreCase("t")==0) {
request = new BindTransmitter();
} else if (bindOption.compareToIgnoreCase("r")==0) {
request = new BindReceiver();
} else if (bindOption.compareToIgnoreCase("tr")==0) {
request = new BindTransciever();
} else {
System.out.println("Invalid bind mode, expected t, r or tr, got " +
bindOption + ". Operation canceled.");
return;
}
ipAddress = getParam("IP address of SMSC", ipAddress);
port = getParam("Port number", port);
TCPIPConnection connection = new TCPIPConnection(ipAddress, port);
connection.setReceiveTimeout(20*1000);
session = new Session(connection);
systemId = getParam("Your system ID", systemId);
password = getParam("Your password", password);
// set values
request.setSystemId(systemId);
request.setPassword(password);
request.setSystemType(systemType);
request.setInterfaceVersion((byte)0x34);
request.setAddressRange(addressRange);
// send the request
System.out.println("Bind request " + request.debugString());
if (asynchronous) {
pduListener = new SMPPTestPDUEventListener(session);
response = session.bind(request,pduListener);
} else {
response = session.bind(request);
}
System.out.println("Bind response " + response.debugString());
if (response.getCommandStatus() == Data.ESME_ROK) {
System.out.println("CommandID "+response.getCommandId());
bound = true;
}
} catch (Exception e) {
event.write(e,"");
debug.write("Bind operation failed. " + e);
System.out.println("Bind operation failed. " + e);
} finally {
debug.exit(this);
}
}
the code for enquiry link is
private void kirimEnquireLink()
{
try
{
log.info("Send enquireLink!");
EnquireLink request = new EnquireLink();
EnquireLinkResp response = new EnquireLinkResp();
// synchronized (session) {
// session.enquireLink(request);
// }
if(asynchronous)
{
session.enquireLink(request);
}else
{
response = session.enquireLink(request);
System.out.println("Enquire Link Response "+request.debugString());
}
}
catch (Exception e)
{
bound = false;
// unbind();
log.error(e, e);
}
}
i called enquiry link every 10 second,, any idea why

The problem you are facing is that there is never insurance that connection will be always available, nor the session. Many different external reasons can bring the link between ESME and SMSC down. My suggestion, try-catch the enquire_link operations and the submit operations, evaluate the Exception and take action.
I've successfully implemented recursive method calls to deal with this issue as follows
/**
* Connect to ESME and submit a message, if binding process fails, reattempt
* to reconnect and submit.
*/
public void connect() {
try {
//Create connection
BindRequest request = null;
request = new BindTransciever();
connection = new TCPIPConnection("localhost", 17632);
connection.setReceiveTimeout(20 * 1000);
session = new Session(connection);
//Prepare request
request.setSystemId("pavel");
request.setPassword("wpsd");
request.setSystemType("CMT");
request.setInterfaceVersion((byte) 0x34);
request.setAddressRange(new AddressRange());
pduListener = new SMPPTestPDUEventListener(session);
//Session binding process, if it fails, we are thrown to the catch section
//with a BrokenPipe (IOException)
session.bind(request, pduListener);
//Prepare message
SubmitSM msg = new SubmitSM();
// set values
msg.setDestAddr("04234143939");
msg.setShortMessage("hello");
msg.assignSequenceNumber(true);
//Send to our custom made submitMessage method that reattempts if failure
submitMessage(msg);
} catch (Exception ex){
//Analyze what type of exception was
if (ex instanceof IOException || ex instanceof SocketException){
//IOException relate to the brokenpipe issue you are facing
//you need to close existing sessions and connections
//restablish session
if (this.connection!=null){
this.connection.close();
}
//This is a recursive call, I encourage you to elaborate
//a little bit this method implementing a counter so you
//don't end up in an infinite loop
this.connect();
} else {
//LOG whatever other exception thrown
}
}
}
/**
* Submit message to SMSC, if it fails because of a connection issue, reattempt
* #param message
*/
private void submitMessage(SubmitSM message){
try{
session.submit(message);
} catch (Exception ex){
//Analyze what type of exception was
if (ex instanceof IOException || ex instanceof SocketException){
//IOException relate to the brokenpipe issue you are facing
//you need to close existing sessions and connections
//restablish session and try to submit again
if (this.connection!=null){
this.connection.close();
}
//Call a rebind method
this.bind();
//This is a recursive call, I encourage you to elaborate
//a little bit this method implementing a counter so you
//don't end up in an infinite loop
this.submitMessage(message);
} else {
//LOG whatever other exception thrown
}
}
}
Do the same with the enquire_link, try-catch, during IOException rebind, and reattempt. Do not forget to add a couter and a maximum ammount of attempts in order to avoid infinite loops during recursive calls.
You do not need to enquire_link every 10 seconds. Most providers will let you know how often it needs to be done, the standard is 10 minutes.

Java RMI server side threading

I'm just getting started with RMI and I'm trying to write a simple program that simulates a train booking system. I have the basics set up - Server, Client, and a Remote object exported. It works fine with one Client connection. However when more than 1 Client connects, the Clients seem to be executing in the same thread. This is the case when I run multiple Clients on the same machine or when I connect a Client from another laptop.
I was under the impression that RMI handled threading on the server side? If not, how do I go about handling multiple Client connections given the code below?
Here are the classes of interest.
Server.....
public class Server {
public Server() {
try {
Booking stub = (Booking) UnicastRemoteObject.exportObject(new BookingProcess(), 0);
Registry registry = LocateRegistry.getRegistry();
registry.bind("Booking", stub);
System.err.println("Server Ready");
} catch (RemoteException e) {
System.err.println("Server exception: " + e.toString());
e.printStackTrace();
} catch (AlreadyBoundException e) {
System.err.println("Server exception: " + e.toString());
e.printStackTrace();
}
}
public static void main(String[] args) {
Server server = new Server();
}
}
BookingProcess.....(I've left out the private methods that processInput(String input) uses)
public class BookingProcess implements Booking {
private static Journey dublinGalway = new Journey("Dublin to Galway");
private static Journey dublinLimerick = new Journey("Dublin to Limerick");
private static Journey dublinCork = new Journey("Dublin to Cork");
private Journey currentJourney;
private enum State {
INITIAL, JOURNEYS_DISPLAYED, JOURNEY_CHOSEN, ANOTHER_BOOKING_OFFERED, SOLD_OUT;
}
private State currentState = State.INITIAL;
public synchronized String processInput(String input) {
String output = "";
if(currentState == State.INITIAL) {
if(bookedOut()) {
output = "Sorry, there are no seats remaining on any route. Get the bus.";
currentState = State.SOLD_OUT;
}
else {
output = "Please choose a journey to book: " + "1: " + dublinGalway.getDescription() + ", 2: " + dublinLimerick.getDescription() + ", 3: " + dublinCork.getDescription();
currentState = State.JOURNEYS_DISPLAYED;
}
}
else if(currentState == State.JOURNEYS_DISPLAYED) {
output = this.processJourneyChoice(input);
}
else if(currentState == State.JOURNEY_CHOSEN) {
output = "Do you wish to confirm this booking? (y/n)";
if(input.equalsIgnoreCase("y")) {
if(bookingConfirmed()) {
output = "Thank you. Your journey from " + currentJourney.getDescription() + " is confirmed. Hit return to continue.";
//currentState = State.ANOTHER_BOOKING_OFFERED;
}
else {
output = "Sorry, but the last seat on the " + currentJourney.getDescription() + " route has just been booked by another user.";
//currentState = State.ANOTHER_BOOKING_OFFERED;
}
currentState = State.ANOTHER_BOOKING_OFFERED;
}
else if(input.equalsIgnoreCase("n")) {
output = "You have cancelled this booking. Hit return to continue.";
currentState = State.ANOTHER_BOOKING_OFFERED;
}
}
else if(currentState == State.ANOTHER_BOOKING_OFFERED) {
output = "Would you like to make another booking? (y/n)";
if(input.equalsIgnoreCase("y")) {
output = "Hit Return to continue.";
currentState = State.INITIAL;
}
else if(input.equalsIgnoreCase("n")){
output = "Goodbye.";
try {
Thread.currentThread().join(10);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
currentState = State.INITIAL;
}
}
else if(currentState == State.SOLD_OUT) {
output = "Goodbye.";
}
return output;
}
And finally Client......
public class Client {
public static void main(String[] args) {
Client client = new Client();
client.runClient();
}
public void runClient() {
try {
BufferedReader consoleInput = new BufferedReader(new InputStreamReader(System.in));
Registry registry = LocateRegistry.getRegistry("localhost");
Booking stub = (Booking) registry.lookup("Booking");
String serverResponse = stub.processInput("begin");
System.out.println("Server: " + serverResponse);
while((serverResponse = stub.processInput(consoleInput.readLine())) != null) {
System.out.println(serverResponse);
if(serverResponse.equals("Goodbye.")) {
break;
}
}
} catch (Exception e) {
System.err.println("Client exception " + e.toString());
e.printStackTrace();
}
}
}

As for as RMI server threads, the answer is that it may or may not run in a separate thread. See the documentation here:
http://docs.oracle.com/javase/6/docs/platform/rmi/spec/rmi-arch3.html
3.2 Thread Usage in Remote Method Invocations
A method dispatched by the RMI runtime to a remote object implementation may or may not execute in a separate thread. The RMI runtime makes no guarantees with respect to mapping remote object invocations to threads. Since remote method invocation on the same remote object may execute concurrently, a remote object implementation needs to make sure its implementation is thread-safe.
You can take server side thread dumps and you would see that the RMI TCP Connection threads IDs keep changing, however as #jtahlborn noticed the server side method is synchronized so it would execute serially, not necessarily in a single thread though.

Your server side processInput() method is synchronized, so, yes, the calls will be handled serially. what does that have to do with RMI?
UPDATE:
if you want to have separate currentState and currentJourney values for each client session, then you need to use the RMI remote session pattern, see this answer for details.

login in flex and java using multithreading

I have problem with my login application in java and flex. we use fingerprint login. the system waits for 60 seconds for any fingerprint input from the user. After that it automatically goes out of the page. The user also has text password option on that page. When user clicks on that option, control goes to some other page. But the problem is whenver user click on text password option, he is redirected but the thread of 60 seconds keep running. Can any one help me how to stop that thread. Here is my code. I am using blocking queue concept to get out of the input screen by inputting some dummy value of one bit.
private void interruptCaptureProcess() {
System.out.println("Interrupting Capture Process.");
ExactScheduledRunnable fingerScanInterruptThread = new ExactScheduledRunnable()
{
public void run()
{
try
{
if (capture != null)
{
DPFPSampleFactoryImpl test = new DPFPSampleFactoryImpl();
samples.put(test.createSample(new byte[1]));
capture.stopCapture();
}
}
catch (Exception e)
{
LOGGER.error("interruptCaptureProcess", e);
e.printStackTrace();
}
}
};
timeOutScheduler.schedule(fingerScanInterruptThread, getTimeOutValue(), TimeUnit.SECONDS);
}
/**
* Scans and Verifies the user finger print by matching it with the previous registered template for the user.
*
* #param userVO is the user value object which has to be verified.
* #return the acknowledgment string according to result for operation performed.
* #throws UserServiceException when there is an error in case of getting user record.
*/
public String verifyUserFingerPrint(Long userId) throws LoginServiceException {
System.out.println("Performing fingerprint verification...\n");
interruptCaptureProcess();
UserVO userVO = null;
try {
userVO = new UserService().findUserById(userId, true);
if (userVO != null) {
stopCaptureProcess();
DPFPSample sample = getSample(selectReader(), "Scan your finger\n");
timeOutScheduler.shutdownNow();
if (sample.serialize().length == 1) {
System.out.println("Coming in code");
return null;
} else if (sample.serialize().length == 2) {
System.out.println("Capturing Process has been Timed-Out");
return TIMEOUT;
}
if (sample == null)
throw new UserServiceException("Error in scanning finger");
DPFPFeatureExtraction featureExtractor = DPFPGlobal.getFeatureExtractionFactory()
.createFeatureExtraction();
DPFPFeatureSet featureSet = featureExtractor.createFeatureSet(sample,
DPFPDataPurpose.DATA_PURPOSE_VERIFICATION);
DPFPVerification matcher = DPFPGlobal.getVerificationFactory().createVerification();
matcher.setFARRequested(DPFPVerification.MEDIUM_SECURITY_FAR);
byte[] tempByte = userVO.getFingerPrint();
DPFPTemplateFactory facotory = new DPFPTemplateFactoryImpl();
for (DPFPFingerIndex finger : DPFPFingerIndex.values()) {
DPFPTemplate template = facotory.createTemplate(tempByte);
if (template != null) {
DPFPVerificationResult result = matcher.verify(featureSet, template);
// Fix of enh#1029
Map<ScriptRxConfigType, Map<ScriptRxConfigName, String>> scriptRxConfigMap = ScriptRxConfigMapSingleton
.getInstance().getScriptRxConfigMap();
Map<ScriptRxConfigName, String> fingerPrintPropertiesMap = scriptRxConfigMap
.get(ScriptRxConfigType.FINGERPRINT);
String fingerPrintDemoMode = fingerPrintPropertiesMap.get(ScriptRxConfigName.DEMOMODE);
if (fingerPrintDemoMode != null && fingerPrintDemoMode.equalsIgnoreCase("DemoEnabled")) {
return "LOGS_MSG_101";
}
// End of fix of enh#1029
if (result.isVerified()) {
System.out.println("Matching finger: %s, FAR achieved: %g.\n" + fingerName(finger)
+ (double) result.getFalseAcceptRate() / DPFPVerification.PROBABILITY_ONE);
return "LOGS_MSG_101";
}
}
}
}
} catch (IndexOutOfBoundsException iob) {
LOGGER.error("verifyUserFingerPrint", iob);
throw new LoginServiceException("LOGS_ERR_101", iob);
} catch (Exception exp) {
LOGGER.error("verifyUserFingerPrint", exp);
System.out.println("Failed to perform verification.");
throw new LoginServiceException("LOGS_ERR_105", exp);
} catch (Throwable th) {
LOGGER.error("verifyUserFingerPrint", th);
throw new LoginServiceException("LOGS_ERR_106", th.getMessage(), th);
}
System.out.println("No matching fingers found for \"%s\".\n" + userVO.getFirstName().toUpperCase());
throw new LoginServiceException("LOGS_ERR_107", null);
}
/* finger scanning process
*/
private void stopCaptureProcess() {
ExactScheduledRunnable fingerScanInterruptThread = new ExactScheduledRunnable() {
public void run() {
try {
DPFPSampleFactoryImpl test = new DPFPSampleFactoryImpl();
samples.put(test.createSample(new byte[2]));
capture.stopCapture();
} catch (Throwable ex) {
ex.printStackTrace();
}
}
};
timeOutScheduler.schedule(fingerScanInterruptThread, getTimeOutValue(), TimeUnit.SECONDS);
}
/**
* API will get the value for the finger scanner time out configuration(Default will be 60 seconds)
*/
private long getTimeOutValue() {
long waitTime = 60;
String configValue = ScriptRxSingleton.getInstance().getConfigurationValue(ConfigType.Security,
ConfigName.FingerprintTimeout);
try {
waitTime = Long.valueOf(configValue);
} catch (NumberFormatException e) {
LOGGER.debug("Configuration value is not a number for FingerTimeOut", e);
}
return waitTime;
}

Stopping blocking tasks in Java is a complicated topic, and requires cooperation between the blocking code and the code that wants to unblock it. The most common way in Java is to interrupt the thread that is blocking, which works if the code that is blocking and the code around it understands interruption. If that's not the case you're out of luck. Here's an answer that explains one way to interrupt a thread that is blocking in an Executor: https://stackoverflow.com/a/9281038/1109