i m trying to get session data,but i m not able to get it bcoz i m not able to get request object...
code is...
package secondary.util;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import org.apache.struts2.interceptor.ServletRequestAware;
import com.opensymphony.xwork2.ActionSupport;
public class GetUserData extends ActionSupport implements ServletRequestAware
{
private static final long serialVersionUID = 1L;
private HttpServletRequest request;
private HttpSession session;
#Override
public void setServletRequest(HttpServletRequest arg0) {
this.setServletRequest(arg0);
session = request.getSession();
}
public HttpServletRequest getRequest() {
return request;
}
public void setRequest(HttpServletRequest request) {
this.request = request;
}
public GetUserData()
{
}
public String getUserLocation()
{
session = request.getSession(); // <- here
String []usr_dtl = session.getAttribute("USERDETAIL").toString().split("#");
System.out.println("User name = " + usr_dtl[6]);
return "DONE";
}
}
it gives nullpointerexception when i m getting session that portion i mark...
session = request.getSession( true );
if there is no current session and create is true, returns a new session.
UPDATE:
your request is null cause you never set the HttpServletRequest in setServletRequest().
Try
this.setRequest(arg0);
instead of
this.setServletRequest(arg0);
Related
My application is generating a request and then sending that request to a listener(activemq here) for further processing, I am trying to add a request-id to the logs for better tracing of errors but the request-id is not passing to the listener it works fine before that, i have tried the approach mentioned in this answer https://stackoverflow.com/a/70892802/19343662
These are the files i have created...
RequestIdFilter:
package com.cashfree.common.dexterreport.filters;
import io.vertx.core.http.HttpServerRequest;
import java.util.UUID;
import javax.ws.rs.container.ContainerRequestContext;
import javax.ws.rs.container.ContainerRequestFilter;
import javax.ws.rs.container.ContainerResponseContext;
import javax.ws.rs.container.ContainerResponseFilter;
import javax.ws.rs.core.Context;
import javax.ws.rs.ext.Provider;
import org.slf4j.MDC;
#Provider
public class RequestIdFilter implements ContainerRequestFilter, ContainerResponseFilter {
#Context
HttpServerRequest request;
private static final String REQUEST_ID_HEADER_NAME = "X-Request-Id";
private static final String REQUEST_ID = "requestId";
#Override
public void filter(ContainerRequestContext context) {
MDC.put(REQUEST_ID, getRequestIdFromHeader(request));
}
#Override
public void filter(ContainerRequestContext requestContext, ContainerResponseContext responseContext) {
MDC.remove(REQUEST_ID);
}
private String getRequestIdFromHeader(final HttpServerRequest request) {
String requestId = request.getHeader(REQUEST_ID_HEADER_NAME);
if (requestId == null || requestId.length() == 0) {
requestId = generateUniqueRequestId();
}
return requestId;
}
private String generateUniqueRequestId() {
return UUID.randomUUID().toString();
}
}
MdcContextProvider
import java.util.Map;
import org.eclipse.microprofile.context.spi.ThreadContextProvider;
import org.eclipse.microprofile.context.spi.ThreadContextSnapshot;
import org.slf4j.MDC;
public class MdcContextProvider implements ThreadContextProvider {
#Override
public ThreadContextSnapshot currentContext(Map<String, String> props) {
Map<String, String> propagate = MDC.getCopyOfContextMap();
return () -> {
Map<String, String> old = MDC.getCopyOfContextMap();
MDC.setContextMap(propagate);
return () -> {
MDC.setContextMap(old);
};
};
}
#Override
public ThreadContextSnapshot clearedContext(Map<String, String> props) {
return () -> {
Map<String, String> old = MDC.getCopyOfContextMap();
MDC.clear();
return () -> {
MDC.setContextMap(old);
};
};
}
#Override
public String getThreadContextType() {
return "SLF4J MDC";
}
}
A ThreadContextProvider file created at src/main/resources/META-INF/services/org.eclipse.microprofile.context.spi.ThreadContextProvider having line specifying the ref path of mdcContextProvider : com.org.common.report.Provider.MdcContextProvider
But this is not working although i was expecting this, since the the thread started by listener and the thread which passes the message to it has no connection between them, is there any way where i can pass the request-id to the listener...
I was able to do it with a workaround.
Because each Listener runs/spawn up its own thread. you cannot expect the request ID to be available in MDC property as MDC property is thread local.
I was able to achieve it by passing the value as part of ActiveMQ's message
Example:
Wrap every message you exchange in a Generic class
class ActiveMqMsg {
private Message message;
private Map<String, Object> properties;
}
and expect Listener to deserialize it to ActiveMqMsg and read the properties and set it to MDC property again.
Hope this helps.
Hi I'm new on RestLet this is a simple example that I want to post a Json representation but after running the client I have error which is mentioned in the below.please help me in this regard.Thank you so much.
The resource :
import org.json.JSONException;
import org.json.JSONObject;
import org.restlet.ext.json.JsonRepresentation;
import org.restlet.resource.Post;
import org.restlet.resource.ServerResource;
import org.restlet.data.Status;
public class DepResource extends ServerResource{
String jsonString="";
#Post
public void acceptJsonRepresentation(JsonRepresentation entity) {
JSONObject json = null;
try {
json = entity.getJsonObject();
// business logic and persistence
String jsonPost=json.toString();
System.out.println(jsonPost);
} catch (JSONException e) {
setStatus(Status.CLIENT_ERROR_BAD_REQUEST);
return;
}
}
}
The client has Error in line 44
import java.io.IOException;
import java.net.InetAddress;
import org.json.JSONException;
import org.json.JSONObject;
import org.restlet.data.CharacterSet;
import org.restlet.data.Method;
import org.restlet.ext.json.JsonRepresentation;
import org.restlet.resource.ClientResource;
public class Client {
public static void main(String[] args) throws JSONException, IOException {
/**##POST Prepration##**/
JSONObject jsonObjectGraph = new JSONObject();
jsonObjectGraph.put("Traffic", 100);
jsonObjectGraph.put("Disksize", 20);
String str=jsonObjectGraph.toString();
JsonRepresentation JRRepDep = new JsonRepresentation(str);
JRRepDep.setCharacterSet(CharacterSet.UTF_8);
System.out.println("with jsonrepresentation: "+JRRepDep.getText());
// TODO Auto-generated method stub
/**********POST**************/
String baseURL1 = "http://" + InetAddress.getLocalHost().getHostAddress() + ":" + "8181";
// Specifying the URL for the resource
String resourceName = "/files";
String ApplicationServerName = baseURL1 + resourceName;
System.out.println("URI at client: " +ApplicationServerName);
// Specifying the REST client and post to REST server
ClientResource restletClient = new ClientResource(ApplicationServerName);
System.out.println(ApplicationServerName);
restletClient.setMethod(Method.POST);
System.out.println("dovomi");
restletClient.post(JRRepDep);
System.out.println("After post");
// Checking the status of the post request
if (restletClient.getStatus().isSuccess())
{
System.out.println("POST Request success.");
restletClient.release();
}
}
}
The server is running without any error
import java.net.InetAddress;
import org.restlet.Application;
import org.restlet.Restlet;
import org.restlet.Server;
import org.restlet.data.Protocol;
import org.restlet.routing.Router;
public class DepServer extends Application {
private static String ipAddress;
private static int port;
public static String getURI()
{
return "http://" + ipAddress + ":" + port;
}
public static void main(String[] args) {
try {
ipAddress = InetAddress.getLocalHost().getHostAddress();
port = 8181;
Server server = new Server(Protocol.HTTP, ipAddress, port);
server.setNext(new DepServer());
server.start();
System.out.print("Server is running");
} catch (Exception e) {
e.printStackTrace();
}
}
#Override
public Restlet createInboundRoot() {
String baseURL = "http://" + ipAddress + ":" + port;
// Create a router restlet.
Router router = new Router(getContext());
// Attach the resources to the router.
router.attach(baseURL + "/files", DepResource.class);
// Return the root router
return router;
}
}
Error:
Jul 20, 2019 2:00:03 PM org.restlet.engine.http.connector.HttpClientHelper start
INFO: Starting the default HTTP client
Exception in thread "main" Internal Server Error (500) - Internal Server Error
at org.restlet.resource.ClientResource.handle(ClientResource.java:870)
at org.restlet.resource.ClientResource.post(ClientResource.java:1209)
at Client.main(Client.java:44)
The question is quite unclear, but if you're asking how to return a JsonRepresentation then you must not return a void but rather a JsonRepresentation see:
public class DepResource extends ServerResource {
String jsonString="{}";
#Post
public JsonRepresentation acceptJsonRepresentation(JsonRepresentation entity) {
// do stuff and return a JsonRepresentation object
Representation representation = new JsonRepresentation(jsonString);
return representation;
}
}
I'm continuing on with a logging behavior using the WebSocketBehavior. It currently logs the correct data to a console, but also throws a terrible serialization error. It is because I am providing the WicketApplication itself as a constructor argument for the behavior. I've tried passing it my session object and using that to get the WebApplication, but it consistently returns null. The broadcaster object requires the application in order to function properly. My question is how can I provide the WebApplication to the behavior while avoiding the nasty serialization error?? Here is my behavior class:
public class LogWebSocketBehavior extends WebSocketBehavior implements Serializable {
private static final long serialVersionUID = 1L;
private Console console;
private Handler logHandler;
private Model<LogRecord> model = new Model<>();
private WebApplication application;
public LogWebSocketBehavior(Console console, WebApplication application) {
super();
configureLogger();
this.console = console;
this.application = application;
}
private void configureLogger() {
Enumeration<String> list = LogManager.getLogManager().getLoggerNames();
list.hasMoreElements();
Logger l = Logger.getLogger(AppUtils.loggerName);
l.addHandler(getLoggerHandler());
}
#Override
protected synchronized void onPush(WebSocketRequestHandler handler, IWebSocketPushMessage message) {
LogRecord r = model.getObject();
sendRecordToConsole(handler, r);
}
private Handler getLoggerHandler() {
return new LogHandler() {
private static final long serialVersionUID = 1L;
#Override
public void publish(LogRecord record) {
model.setObject(record);
sendToAllConnectedClients("data");
}
};
}
private synchronized void sendToAllConnectedClients(String message) {
IWebSocketConnectionRegistry registry = new SimpleWebSocketConnectionRegistry();
WebSocketPushBroadcaster b = new WebSocketPushBroadcaster(registry);
b.broadcastAll(application, new Message());
}
private void sendRecordToConsole(WebSocketRequestHandler handler, LogRecord r) {
Level level = r.getLevel();
if (level.equals(Level.INFO)) {
console.info(handler, new SimpleFormatter().formatMessage(r));
} else {
console.error(handler, new SimpleFormatter().formatMessage(r));
}
}
class Message implements IWebSocketPushMessage {
public Message() {
}
}
}
Here is the panel that is being used to display the messages:
public class FooterPanel extends Panel {
private static final long serialVersionUID = 1L;
private Form form;
private Console console;
public FooterPanel(String id) {
super(id);
}
#Override
public void onInitialize() {
super.onInitialize();
form = new Form("form");
form.add(console = getConsole("feedback_console"));
console.setOutputMarkupId(true);
form.setOutputMarkupId(true);
add(form);
add(getLoggingBehavior());
}
private Console getConsole(String id) {
return new Console(id) {
private static final long serialVersionUID = 1L;
};
}
private WebSocketBehavior getLoggingBehavior() {
return new LogWebSocketBehavior(console, this.getWebApplication());
}
}
I updated my behavior as follows:
public class LogWebSocketBehavior extends WebSocketBehavior implements Serializable {
private static final long serialVersionUID = 1L;
private Console console;
private Handler logHandler;
private Model<LogRecord> model = new Model<>();
public LogWebSocketBehavior(Console console) {
super();
configureLogger();
this.console = console;
}
private void configureLogger() {
Enumeration<String> list = LogManager.getLogManager().getLoggerNames();
list.hasMoreElements();
Logger l = Logger.getLogger(AppUtils.loggerName);
l.addHandler(getLoggerHandler());
}
#Override
protected synchronized void onPush(WebSocketRequestHandler handler, IWebSocketPushMessage message) {
LogRecord r = model.getObject();
sendRecordToConsole(handler, r);
}
private Handler getLoggerHandler() {
return new LogHandler() {
private static final long serialVersionUID = 1L;
#Override
public void publish(LogRecord record) {
model.setObject(record);
sendToAllConnectedClients("data");
}
};
}
private synchronized void sendToAllConnectedClients(String message) {
WebApplication application = WebApplication.get();
IWebSocketConnectionRegistry registry = new SimpleWebSocketConnectionRegistry();
WebSocketPushBroadcaster b = new WebSocketPushBroadcaster(registry);
b.broadcastAll(application, new Message());
}
private void sendRecordToConsole(WebSocketRequestHandler handler, LogRecord r) {
Level level = r.getLevel();
String message = AppUtils.consoleDateTimeFormat.format(LocalDateTime.now()) + " - " + AppUtils.LogFormatter.formatMessage(r);
if (level.equals(Level.INFO)) {
console.info(handler, message);
} else {
console.error(handler, message);
}
}
class Message implements IWebSocketPushMessage {
public Message() {
}
}
}
And I'm back to the original issues I started with, which is the following error:
ERROR - ErrorLogger - Job (report.DB5E002E046235586592E7E984338DEE3 : 653 threw an exception.
org.quartz.SchedulerException:
Job threw an unhandled exception. [See nested exception: org.apache.wicket.WicketRuntimeException: There is no application attached to current thread DefaultQuartzScheduler_Worker-1]
at org.quartz.core.JobRunShell.run(JobRunShell.java:213)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:573)
Caused by: org.apache.wicket.WicketRuntimeException: There is no application attached to current thread DefaultQuartzScheduler_Worker-1
at org.apache.wicket.Application.get(Application.java:236)
at org.apache.wicket.protocol.http.WebApplication.get(WebApplication.java:160)
at eb.wicket.behaviors.LogWebSocketBehavior.sendToAllConnectedClients(LogWebSocketBehavior.java:77)
at eb.wicket.behaviors.LogWebSocketBehavior.access$100(LogWebSocketBehavior.java:29)
at eb.wicket.behaviors.LogWebSocketBehavior$1.publish(LogWebSocketBehavior.java:70)
Finally working as desired.. Here's the behavior class:
public class LogWebSocketBehavior extends WebSocketBehavior implements Serializable {
private static final long serialVersionUID = 1L;
private Console console;
private Model<LogRecord> model = new Model<>();
public LogWebSocketBehavior(Console console) {
super();
configureLogger();
this.console = console;
}
private void configureLogger() {
Enumeration<String> list = LogManager.getLogManager().getLoggerNames();
list.hasMoreElements();
Logger l = Logger.getLogger(AppUtils.loggerName);
l.addHandler(getLoggerHandler());
}
#Override
protected synchronized void onPush(WebSocketRequestHandler handler, IWebSocketPushMessage message) {
LogRecord r = model.getObject();
sendRecordToConsole(handler, r);
}
private Handler getLoggerHandler() {
return new LogHandler() {
private static final long serialVersionUID = 1L;
#Override
public void publish(LogRecord record) {
model.setObject(record);
sendToAllConnectedClients("data");
}
};
}
private synchronized void sendToAllConnectedClients(String message) {
IWebSocketConnectionRegistry registry = new SimpleWebSocketConnectionRegistry();
WebSocketPushBroadcaster b = new WebSocketPushBroadcaster(registry);
b.broadcastAll(Application.get("eb.wicket.MyWicketFilter"), new Message());
}
private void sendRecordToConsole(WebSocketRequestHandler handler, LogRecord r) {
Level level = r.getLevel();
String message = AppUtils.consoleDateTimeFormat.format(LocalDateTime.now()) + " - " + AppUtils.LogFormatter.formatMessage(r);
if (level.equals(Level.INFO)) {
console.info(handler, message);
} else {
console.error(handler, message);
}
}
class Message implements IWebSocketPushMessage {
public Message() {
}
}
}
Instead of keeping a reference to the Application just look it up when needed: Application.get().
After updating your question we can see:
Caused by: org.apache.wicket.WicketRuntimeException:
There is no application attached to current thread DefaultQuartzScheduler_Worker-1
This explains it - this is a thread started by Quartz, it is not a http thread.
The only way to overcome this is to use Application.get(String). The value should be the application name (Application#getName()) that is specified as a value for <filter-name> in your web.xml.
This way you can get the Application instance, but there is no way to do the same for Session and/or RequestCycle in case you need them too.
I am trying to integrate the Apache FTP server into my application. I have followed the instructions given here but have run into some problems. Currently I am able to run the server and connect to it from my browser but can not log in. I have tried admin/admin and anonymous/*, but the login fails every time. In the apache-ftpserver-1.0.6 source code I had downloaded, the files associated with the user manager are located in res/conf, although when I try to match that file path in my own program I get an error that says "invalid resource directory name" and am unable to build. I also tried including the files users.properties and ftpd-typical.xml in the main directly and can run, but again cannot log in. It seems like my project does not realize these files are present.
Does anyone have experience with Apache FTP Server that could tell me the correct way to include these files so that I can log in to my server?
Thanks!
P.S. I don't think it should make any difference, but I am developing this program for Android.
In the following code I am crating admin user and non-admin user, setting restrictions of reading, writing and restricting throttling and upload rate limit and imposing download rate limiting.
Added a listener to listen user login and logout download start and download finish events.
import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.ftpserver.FtpServer;
import org.apache.ftpserver.FtpServerFactory;
import org.apache.ftpserver.ftplet.Authority;
import org.apache.ftpserver.ftplet.FileSystemFactory;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.Ftplet;
import org.apache.ftpserver.ftplet.UserManager;
import org.apache.ftpserver.ftpletcontainer.impl.DefaultFtpletContainer;
import org.apache.ftpserver.listener.ListenerFactory;
import org.apache.ftpserver.usermanager.PropertiesUserManagerFactory;
import org.apache.ftpserver.usermanager.SaltedPasswordEncryptor;
import org.apache.ftpserver.usermanager.impl.BaseUser;
import org.apache.ftpserver.usermanager.impl.ConcurrentLoginPermission;
import org.apache.ftpserver.usermanager.impl.TransferRatePermission;
import org.apache.ftpserver.usermanager.impl.WritePermission;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class SFTPServer {
// ===========================================================
// Constants
// ===========================================================
private final int FTP_PORT = 2221;
private final String DEFAULT_LISTENER = "default";
// private final Logger LOG = LoggerFactory.getLogger(SFTPServer.class);
private static final List<Authority> ADMIN_AUTHORITIES;
private static final int BYTES_PER_KB = 1024;
private static final String DEFAULT_USER_DIR = "C:\\upload";
public final static int MAX_CONCURRENT_LOGINS = 1;
public final static int MAX_CONCURRENT_LOGINS_PER_IP = 1;
// ===========================================================
// Fields
// ===========================================================
private static FtpServer mFTPServer;
private static UserManager mUserManager;
private static FtpServerFactory mFTPServerFactory;
private ListenerFactory mListenerFactor;
// ===========================================================
// Constructors
// ===========================================================
static {
// Admin Authorities
ADMIN_AUTHORITIES = new ArrayList<Authority>();
ADMIN_AUTHORITIES.add(new WritePermission());
ADMIN_AUTHORITIES.add(new ConcurrentLoginPermission(MAX_CONCURRENT_LOGINS, MAX_CONCURRENT_LOGINS_PER_IP));
ADMIN_AUTHORITIES.add(new TransferRatePermission(Integer.MAX_VALUE, Integer.MAX_VALUE));
}
// ===========================================================
// Getter & Setter
// ===========================================================
// ===========================================================
// Methods for/from SuperClass/Interfaces
// ===========================================================
// ===========================================================
// Methods
// ===========================================================
public void init() throws FtpException {
mFTPServerFactory = new FtpServerFactory();
mListenerFactor = new ListenerFactory();
mListenerFactor.setPort(FTP_PORT);
mFTPServerFactory.addListener(DEFAULT_LISTENER, mListenerFactor.createListener());
mFTPServerFactory.getFtplets().put(FTPLetImpl.class.getName(), new FTPLetImpl());
PropertiesUserManagerFactory userManagerFactory = new PropertiesUserManagerFactory();
userManagerFactory.setFile(new File("ftpusers.properties"));
userManagerFactory.setPasswordEncryptor(new SaltedPasswordEncryptor());
mUserManager = userManagerFactory.createUserManager();
mFTPServerFactory.setUserManager(mUserManager);
this.createAdminUser();
SFTPServer.addUser("admin1", "admin1", 20, 20);
mFTPServer = mFTPServerFactory.createServer();
mFTPServer.start();
}
private UserManager createAdminUser() throws FtpException {
UserManager userManager = mFTPServerFactory.getUserManager();
String adminName = userManager.getAdminName();
if (!userManager.doesExist(adminName)) {
// LOG.info((new
// StringBuilder()).append("Creating user : ").append(adminName).toString());
BaseUser adminUser = new BaseUser();
adminUser.setName(adminName);
adminUser.setPassword(adminName);
adminUser.setEnabled(true);
adminUser.setAuthorities(ADMIN_AUTHORITIES);
adminUser.setHomeDirectory(DEFAULT_USER_DIR);
adminUser.setMaxIdleTime(0);
userManager.save(adminUser);
}
return userManager;
}
public static void addUser(String username, String password, int uploadRateKB, int downloadRateKB) throws FtpException {
BaseUser user = new BaseUser();
user.setName(username);
user.setPassword(password);
user.setHomeDirectory(DEFAULT_USER_DIR);
user.setEnabled(true);
List<Authority> list = new ArrayList<Authority>();
list.add(new TransferRatePermission(downloadRateKB * BYTES_PER_KB, uploadRateKB * BYTES_PER_KB)); // 20KB
list.add(new ConcurrentLoginPermission(MAX_CONCURRENT_LOGINS, MAX_CONCURRENT_LOGINS_PER_IP));
user.setAuthorities(list);
mFTPServerFactory.getUserManager().save(user);
}
public static void restartFTP() throws FtpException {
if (mFTPServer != null) {
mFTPServer.stop();
try {
Thread.sleep(1000 * 3);
} catch (InterruptedException e) {
}
mFTPServer.start();
}
}
public static void stopFTP() throws FtpException {
if (mFTPServer != null) {
mFTPServer.stop();
}
}
public static void pauseFTP() throws FtpException {
if (mFTPServer != null) {
mFTPServer.suspend();
}
}
public static void resumeFTP() throws FtpException {
if (mFTPServer != null) {
mFTPServer.resume();
}
}
public static void main(String... are) {
try {
new SFTPServer().init();
} catch (FtpException e) {
e.printStackTrace();
}
}
// ===========================================================
// Inner and Anonymous Classes
// ===========================================================
}
FTPLET Listener
import java.io.IOException;
import org.apache.ftpserver.ftplet.DefaultFtplet;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.FtpRequest;
import org.apache.ftpserver.ftplet.FtpSession;
import org.apache.ftpserver.ftplet.FtpletResult;
public class FTPLetImpl extends DefaultFtplet {
#Override
public FtpletResult onLogin(FtpSession session, FtpRequest request) throws FtpException, IOException {
System.out.println(session.getUser().getName() + " Logged in");
return super.onLogin(session, request);
}
#Override
public FtpletResult onDisconnect(FtpSession session) throws FtpException, IOException {
System.out.println(session.getUser().getName() + " Disconnected");
return super.onDisconnect(session);
}
#Override
public FtpletResult onDownloadStart(FtpSession session, FtpRequest request) throws FtpException, IOException {
System.out.println(session.getUser().getName() + " Started Downloading File " + request.getArgument());
return super.onDownloadStart(session, request);
}
#Override
public FtpletResult onDownloadEnd(FtpSession session, FtpRequest request) throws FtpException, IOException {
System.out.println("Finished Downloading " + request.getArgument());
return super.onDownloadEnd(session, request);
}
}
The setup
Windows 7 Professionnal
Eclipse Juno
Java jre7
Netty 4.0.0 Beta2
I have a netty server running on another machine. Then I have a program running on my machine, which is made to simulate many clients communicating with the server concurrently. In order to do that, I have a thread pool implemented with java.util.concurrent.ExecutorService . Each client creates a thread and submit it to the ExecutorService. Just before it ends, that thread creates another one with the same code. The submited code does those steps :
connect to server by sending a handshake (netty bootstrap A and channel A)
get the token from the handshake response
connect to server (netty bootstrap B and channel B)
send one request to server
receive the response
close the connection
create another thread with the same code
The problem
I sometimes get a NullPointerException in NettySocketCommunication.sendMessage(), on channel.write(byteBuf) when sending a request to the server.
01728 16:25:23.870 [nioEventLoopGroup-3804-2] ERROR
c.f.s.virtualuser.VirtualUser - java.lang.RuntimeException:
java.lang.NullPointerException at
c.f.s.virtualuser.VirtualUser.processMessageStep(VirtualUser.java:324)
at
c.f.s.virtualuser.VirtualUser.processNextStep(VirtualUser.java:252)
at
c.f.s.virtualuser.VirtualUser.onChannelConnected(VirtualUser.java:395)
at
c.f.s.c.m.handler.ClientSocketBasedHandler.channelActive(ClientSocketBasedHandler.java:95)
at
io.netty.channel.DefaultChannelHandlerContext.invokeChannelActive(DefaultChannelHandlerContext.java:774)
at
io.netty.channel.DefaultChannelHandlerContext.fireChannelActive(DefaultChannelHandlerContext.java:760)
at
io.netty.channel.ChannelStateHandlerAdapter.channelActive(ChannelStateHandlerAdapter.java:58)
at
io.netty.channel.DefaultChannelHandlerContext.invokeChannelActive(DefaultChannelHandlerContext.java:774)
at
io.netty.channel.DefaultChannelHandlerContext.fireChannelActive(DefaultChannelHandlerContext.java:760)
at
io.netty.channel.DefaultChannelPipeline.fireChannelActive(DefaultChannelPipeline.java:884)
at
io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:223)
at
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:417)
at
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:365)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:302) at
io.netty.channel.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:110)
at java.lang.Thread.run(Unknown Source)
Caused by:
java.lang.NullPointerException: null at
c.f.s.c.m.NettySocketCommunication.sendMessage(NettySocketCommunication.java:109)
at
c.f.s.virtualuser.VirtualUser.processMessageStep(VirtualUser.java:317)
... 15 common frames omitted
The code
I removed some logging and comments to make the code blocks shorter. I also have the VirtualUser.java class (not shown here) that implements both IVirtualUserCommunication and IVirtualUserMessages interfaces.
[AbstractVirtualUserCommunication.java]
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundMessageHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.http.DefaultLastHttpContent;
import io.netty.handler.codec.http.HttpRequestEncoder;
import io.netty.handler.codec.http.HttpResponseDecoder;
import io.netty.util.CharsetUtil;
import [...].Amf3;
import [...].Properties;
import [...].LogFactory;
import [...].Logger;
import [...].AbstractRequest;
import [...].IRouterMessage;
import [...].RouterMessage;
import [...].FrimaHandshake;
import [...].IVirtualUserCommunication;
public abstract class AbstractVirtualUserCommunication implements IVirtualUserCommunication
{
protected static Logger Log = LogFactory.getInstance().getLogger(AbstractVirtualUserCommunication.class);
protected String CONFIG_APPLICATION = "target.server.application";
protected String application;
protected String CONFIG_VERSION = "target.server.version";
protected String version;
protected String CONFIG_HANDSHAKE_PORT = "netty.handshake.port";
protected final int defaultHandshakePort = 80;
// The following variables are used by both HTTP and SOCKET communication
protected Bootstrap bootstrapHandshake; // Netty bootstrap used only for handshake
protected Channel channelHandshake; // Netty channel used only for handshake
protected String token; // The token received through handshake process
// Host & port are set in the connect() method
protected String host;
protected int port;
protected Bootstrap bootstrap; // Netty bootstrap used for communication
protected Channel channel; // Netty channel used for communication
/** Connect to the server to get the token */
public void sendHandshake(String host)
{
// Get properties, with default values if they are not specified
this.application = Properties.getString(CONFIG_APPLICATION, "snowstorm");
this.version = Properties.getString(CONFIG_VERSION, "0.0.1");
int handshakePort = Properties.getInt(CONFIG_HANDSHAKE_PORT, defaultHandshakePort);
bootstrapHandshake = new Bootstrap();
try
{
bootstrapHandshake.group(new NioEventLoopGroup());
bootstrapHandshake.channel(NioSocketChannel.class);
bootstrapHandshake.handler(new HandShakeInitializer(/* this */));
// Connect and listen on handshake host/port
channelHandshake = bootstrapHandshake.connect(host, handshakePort).sync().channel();
channelHandshake.closeFuture().sync();
}
catch (InterruptedException e)
{
Log.error(e);
}
finally
{
bootstrapHandshake.shutdown();
}
}
/** Method called after completion of the handshake (the token has been set). */
protected abstract void afterHandshake();
/** Connect to the target server for stress test script execution. */
protected void connect(ChannelHandler handler)
{
bootstrap = new Bootstrap();
try
{
// Initialize the pipeline
bootstrap.group(new NioEventLoopGroup());
bootstrap.channel(NioSocketChannel.class);
bootstrap.handler(handler);
// Connect and listen on host/port
channel = bootstrap.connect(host, port).sync().channel();
if (channel == null)
{
Log.error("PROBLEM : The channel is null in the afterHandshake() method");
}
channel.closeFuture().sync();
}
catch (InterruptedException e)
{
Log.error(e);
}
finally
{
bootstrap.shutdown();
}
}
/** Create a RouterMessage with the specified request. */
protected IRouterMessage buildMessage(AbstractRequest request)
{
RouterMessage routerMessage = new RouterMessage();
routerMessage.bytes = Amf3.serialize(request);
routerMessage.token = this.token;
routerMessage.application = this.application;
routerMessage.version = this.version;
return routerMessage;
}
#Override
public void disconnect()
{
// TODO Is it dangerous to not call channel.close() ??
if (channel != null)
{
channel.close().awaitUninterruptibly();
}
else
{
Log.error("PROBLEM : The channel is null when calling the disconnect() method");
}
bootstrap.shutdown();
}
#Override
public boolean isConnected()
{
if (channel == null)
{
return false;
}
return channel.isActive();
}
private class HandShakeInitializer extends ChannelInitializer<SocketChannel>
{
public HandShakeInitializer()
{
super();
}
#Override
protected void initChannel(SocketChannel socketChannel) throws Exception
{
socketChannel.pipeline().addLast("encoder", new HttpRequestEncoder());
socketChannel.pipeline().addLast("decoder", new HttpResponseDecoder());
socketChannel.pipeline().addLast("handler", new HandShakeHandler(/* communication */));
}
}
private class HandShakeHandler extends ChannelInboundMessageHandlerAdapter<Object>
{
public HandShakeHandler()
{
super();
}
#Override
public void channelActive(ChannelHandlerContext ctx) throws Exception
{
super.channelActive(ctx);
ctx.write(FrimaHandshake.create(null, version, application));
ctx.flush();
}
#Override
public void messageReceived(ChannelHandlerContext ctx, Object msg) throws Exception
{
if (msg instanceof DefaultLastHttpContent)
{
DefaultLastHttpContent defaultLastHttpContent = (DefaultLastHttpContent) msg;
String content = defaultLastHttpContent.data().toString(CharsetUtil.UTF_8);
// Format = token~publicDNS and we only need the token here
token = content;// .split("~")[0];
Log.debug("Starting a bot with token " + token);
afterHandshake();
}
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception
{
Log.error(cause);
ctx.close();
}
}
}
[NettySocketCommunication.java]
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelFuture;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import [...].AbstractRequest;
import [...].IRouterMessage;
import [...].Serializer;
import [...].ClientSocketBasedHandler;
import [...].ClientSocketBasedInitializer;
import [...].IVirtualUserMessages;
public class NettySocketCommunication extends AbstractVirtualUserCommunication
{
private ClientSocketBasedHandler handler;
private ChannelFuture testChannelFuture;
public NettySocketCommunication()
{
super();
Log.setLevelToInfo();
this.handler = new ClientSocketBasedHandler();
}
#Override
public void setVirtualUser(IVirtualUserMessages virtualUser)
{
this.handler.setVirtualUser(virtualUser);
}
#Override
public void connect(String host, int port)
{
this.host = host;
this.port = port;
// Get the token from the server through the handshake process
sendHandshake(host);
}
#Override
public boolean connectTest(String host, int port)
{
boolean connectSuccess = false;
bootstrap = new Bootstrap();
// Initialize the pipeline
bootstrap.group(new NioEventLoopGroup());
bootstrap.channel(NioSocketChannel.class);
bootstrap.handler(new ClientSocketBasedInitializer(new ClientSocketBasedHandler()));
// Listen on host/port (connect a channel)
testChannelFuture = bootstrap.connect(host, port);
testChannelFuture.awaitUninterruptibly();
if (testChannelFuture.isSuccess())
{
connectSuccess = true;
}
testChannelFuture.channel().close().awaitUninterruptibly();
bootstrap.shutdown();
return connectSuccess;
}
#Override
protected void afterHandshake()
{
super.connect(new ClientSocketBasedInitializer(handler));
}
#Override
public void sendMessage(AbstractRequest request)
{
IRouterMessage routerMessage = buildMessage(request);
ByteBuf byteBuf = Serializer.encode(routerMessage, true);
// Send message
channel.write(byteBuf);
channel.flush();
}
}
[ClientSocketBasedHandler.java]
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundMessageHandlerAdapter;
import java.util.ArrayList;
import java.util.List;
import [...].Amf3;
import [...].LogFactory;
import [...].Logger;
import [...].IMessage;
import [...].IRouterMessage;
import [...].IVirtualUserMessages;
public class ClientSocketBasedHandler extends ChannelInboundMessageHandlerAdapter<IRouterMessage>
{
protected static Logger Log = LogFactory.getInstance().getLogger(ClientSocketBasedHandler.class);
private IVirtualUserMessages virtualUser;
public ClientSocketBasedHandler()
{
super();
Log.setLevelToInfo();
}
public void setVirtualUser(IVirtualUserMessages virtualUser)
{
this.virtualUser = virtualUser;
}
#Override
public void messageReceived(ChannelHandlerContext ctx, IRouterMessage routerMessage) throws Exception
{
List<IMessage> messages = deserializeMessages(routerMessage.getBytes());
for (IMessage message : messages)
{
Log.debug("Received socket : " + message);
if (virtualUser == null)
{
throw new RuntimeException("Must call the setVirtualUser() method before receiving messages");
}
virtualUser.onManticoreMessageReceived(message);
}
}
protected List<IMessage> deserializeMessages(byte[] bytes)
{
Object probablyMessages = Amf3.deserialize(bytes);
List<IMessage> messages = null;
// List of Messages
if (probablyMessages instanceof ArrayList)
{
messages = (List<IMessage>) probablyMessages;
}
// Single Message
else if (probablyMessages instanceof IMessage)
{
messages = new ArrayList<IMessage>(1);
messages.add((IMessage) probablyMessages);
}
// Probably Pollution
else
{
Log.error("Cannot deserialize message '{}'", probablyMessages.toString());
}
return messages;
}
#Override
public void channelActive(ChannelHandlerContext ctx)
{
if (virtualUser != null)
{
virtualUser.onChannelConnected();
}
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception
{
Log.error(cause);
ctx.close();
}
}
The search
I looked at netty channels related questions on stack overflow, but couldn't find anything relevant to my case.
Links
http://netty.io/4.0/api/io/netty/channel/Channel.html
http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ExecutorService.html