We are trying to handle a scenario that when a user in quitting a room ,we send a message using MetaBroadcaster to all room .We implemented this feature by override broadcast method of AtmosphereGwtHandler .
The feature is good when we testing in development mode, but when we test it in Jetty8 production mode, telling by log, the override method is void which never get called.
So anybody know what's wrong with it, or do we have a better solution to this feature.
here is our code snippet:
public class ChatHandler extends AtmosphereGwtHandler {
...
#Override
public void broadcast(Object message, GwtAtmosphereResource resource) {
MsgType msgtype=((ChatMessage)message).getMsgtype();
if(msgtype==MsgType.Broad){
MetaBroadcaster.getDefault().broadcastTo(((ChatMessage)message).getChanel(), message);
System.out.println("Doing to all room);
}else{
super.broadcast(message, resource);
System.out.println("Doing to myself);
}
}
}
Can't really give an answer on the info provided.
Where have you configured your handler?
web.xml or atmosphere.xml
What servlet are you using Meteor/Atmosphere?
What version of Atmosphere?
Related
I am trying to implement session timeout with help of a GWT Timer which will make a RPC call to server to check whether the session is valid or expired by using lastaccessedtime. but every time i make a RPC call it updates the lastaccessedtime (understandable as i am making a RPC call), any way i can prevent my Timer RPC call from updating the lastaccessedtime?
wrote some server side logic to get the lastaccessedtime and try to find out session is valid or not
com.google.gwt.user.client.Timer elapsedTimer;
public void onModuleLoad() {
elapsedTimer = new Timer () {
public void run() {
validateSession();
}};
//giving time delay of 1sec to call the batches
elapsedTimer.scheduleRepeating(60000);
}
public void validateSession(){
//Problem code every time i make this call it updates the last accessed time
viewService.validateSessionGWT(new AsyncCallback<ModuleData>() {
#Override
public void onFailure(Throwable e) {
//do something
}
#Override
public void onSuccess(ModuleData data) {
if(data.getSessionExpired()){
//redirect to login page
}
}
});
}
any idea how to overcome this problem or any other idea to implement Session management in GWT
NOTE: already gone through this which is similar to my approach
https://itsecrets.wordpress.com/2011/07/20/session-timeouts-with-gwt-rpc-calls/
Your GWT servlets extend the RemoteServiceServlet. So you can override processPost and add a custom last call timestamp in you http session. Every request updates this field.
I suggest to implement an abstract servlet that is extended by all your gwt servlets. Additionally you should not only set the custom last access field, but check it just before and only call the super method if everything is fine.
Then your timer and the servlet request you already have should only check this Session field.
Perhaps not the best solution but this should work.
I am using Jersey Rest implementation. There are one Rest Services Called HelloWorld. See the below code.
Please consider this code as reference not as compiled code.
#Path("helloWorld")
public class HelloWorld{
#Path("test")
#Produces(...)
#Consum(...)
#GET
public Response test(Person person){
System.out.println(person);
}
}
I am using Jersey client to sent the request.
Here My question is apart from POST method is there any way to send the object to GET method directly. Instead of QueryString.
Please let me if there is any way to do so.
Thanks
So the problem shouldn't be with the server. I did a few tests on different servers (not weblogic as I don't use it) and all of them seem to have no problems accepting a body in the GET request. The problem seem to be with the client. To test I used the following code
ClientBuilder.newClient()
.target("http://localhost:8080/api/get-body")
.property(ClientProperties.SUPPRESS_HTTP_COMPLIANCE_VALIDATION, true)
.request()
.method(HttpMethod.GET, Entity.text("Hello World"));
The SUPPRESS_HTTP_COMPLIANCE_VALIDATION allows us to pass a body to the request. If we didn't use this, then we would get an error.
The problem with this code, is that even though we set this override property, the client completely overrides the GET method and automatically makes it a POST method, so I would get back a 405 Method Not Allowed.
The solution I came up with is to just allow the client to set a header, e.g. X-GET-BODY-OVERRIDE, and then use a #PreMatching filter on the server side to check for this header. If the header is present, then just change the method to a GET
#Provider
#PreMatching
public class GetWithBodyFilter implements ContainerRequestFilter {
#Override
public void filter(ContainerRequestContext request) throws IOException {
String getOverride = request.getHeaderString("X-GET-BODY-OVERRIDE");
if (getOverride != null && "true".equalsIgnoreCase(getOverride)) {
request.setMethod(HttpMethod.GET);
}
}
}
Then just register the filter with the server side. On the client, you would simply need to add the header
ClientBuilder.newClient()
.target("http://localhost:8080/api/get-body")
.property(ClientProperties.SUPPRESS_HTTP_COMPLIANCE_VALIDATION, true)
.request()
.header("X-GET-BODY-OVERRIDE", "True")
.method(HttpMethod.GET, Entity.text("Hello World"));
This solution is good because it takes into account more than just the Jersey client, in regards with being able to send a body in the GET request.
I successfully configured spring-cloud (via spring-cloud-starter-hystrix) to wrap a call to a service.
This all works fine and looks like the following:
#Component
public class MyService {
#HystrixCommand(fallbackMethod = "fallback")
public void longRunning() {
// this could fail
}
public void fallback() {
// fallback code
}
}
My question now is, I would like to log some statistics about the execution error in longRunning()
Trying to access HystrixRequestLog.getCurrentRequest() within the fallback method throws
java.lang.IllegalStateException: HystrixRequestContext.initializeContext() must be called at the beginning of each request before RequestVariable functionality can be used.
I am looking for a simple way to log the exception of longRunning if the fallback is called.
testing with v1.0.0.RC2
To see a stack trace you can just enable DEBUG logging in com.netflix.hystrix.
As far as I can tell, to use the HystrixRequestContext the caller of MyService has to call HystrixRequestContext.initializeContext() before using the service. That sucks, so if anyone has a better idea, I'm interested.
Starting from Javanica v1.4.21, it allows fallback method to have an argument of Throwable type for accessing the command execution exception like so:
public void fallback(Throwable e) {
// fallback code
LOGGER.error(e.getMessage());
}
To get this feature, your build config needs to override the older version of Javanica pulled in by Spring Cloud.
What is best way to attempt multiple time same RPC call while failing RPC call?
just example: Here one case like if RPC get failed due to network connection, it will catch in onFailure(Throwable caught).
Now here it should recall same RPC again for check network connection. The maximum attempt should be 3 times only then show message to user like "Network is not established"
How can I achieve it?
Some couple of thoughts like call same rpc call in onFailure but here request become different.but I want same request have a three request and it is not good approach and I don't know if any good solution for it.
Thanks In Advance.
Use a counter in your AsynCallBack implementation. I recommend as well to use a timer before requesting the server again.
This code should work:
final GreetingServiceAsync greetingService = GWT.create(GreetingService.class);
final String textToServer = "foo";
greetingService.greetServer(textToServer, new AsyncCallback<String>() {
int tries = 0;
public void onSuccess(String result) {
// Do something
}
public void onFailure(Throwable caught) {
if (tries ++ < 3) {
// Optional Enclose the new call in a timer to wait sometime before requesting the server again
new Timer() {
public void run() {
greetingService.greetServer(textToServer, this);
}
}.schedule(4000);
}
}
});
#Jens given this answer from Google Groups.
You could transparently handle this for all your requests of a given GWT-RPC interface by using a custom RpcRequestBuilder. This custom RpcRequestBuilder would make 3 request attempts and if all 3 fail, calls the onFailure() method.
MyRemoteServiceAsync service = GWT.create(MyRemoteService.class);
((ServiceDefTarget) service).setRpcRequestBuilder(new RetryThreeTimesRequestBuilder());
The custom RequestBuilder could also fire a "NetworkFailureEvent" on the eventBus if multiple application components may be interested in that information. For example you could overlay the whole app with a dark screen and periodically try sending Ping requests to your server until network comes back online. There is also the onLine HTML 5 property you can check, but its not 100% reliable (https://developer.mozilla.org/en-US/docs/Web/API/window.navigator.onLine)
Using JAX-WS 2, I see an issue that others have spoken about as well. The issue is that if a SOAP message is received inside a handler, and that SOAP message is large - whether due to inline SOAP body elements that happen to have lots of content, or due to MTOM attachments - then it is dangerously easy to get an OutOfMemoryError.
The reason is that the call to getMessage() seems to set off a chain of events that involve reading the entire SOAP message on the wire, and creating an object (or objects) representing what was on the wire.
For example:
...
public boolean handleMessage(SOAPMessageContext context)
{
// for a large message, this will cause an OutOfMemoryError
System.out.println( context.getMessage().countAttachments() );
...
My question is: is there a known mechanism/workaround for dealing with this? Specifically, it would be nice to access the SOAP part in a SOAP message without forcing the attachments (if MTOM for example) to also be vacuumed up.
For those who run their app on JBoss 6 & 7 (with Apache CXF)... I was able to troubleshoot the problem by implementing my handler from the LogicalHandler interface instead of the SOAPHandler.
In this case your handleMessage() method would get the LogicalMessageContext context (instead of SOAPMessageContext) in the arguments that has no issues with the context.getMessage() call
There's actually a JAX-WS RI (aka Metro) specific solution for this which is very effective.
See https://javaee.github.io/metro/doc/user-guide/ch02.html#efficient-handlers-in-jax-ws-ri. Unfortunately that link is now broken but you can find it on WayBack Machine. I'll give the highlights below:
The Metro folks back in 2007 introduced an additional handler type, MessageHandler<MessageHandlerContext>, which is proprietary to Metro. It is far more efficient than SOAPHandler<SOAPMessageContext> as it doesn't try to do in-memory DOM representation.
Here's the crucial text from the original blog article:
MessageHandler:
Utilizing the extensible Handler framework provided by JAX-WS
Specification and the better Message abstraction in RI, we introduced
a new handler called MessageHandler to extend your Web Service
applications. MessageHandler is similar to SOAPHandler, except that
implementations of it gets access to MessageHandlerContext (an
extension of MessageContext). Through MessageHandlerContext one can
access the Message and process it using the Message API. As I put in
the title of the blog, this handler lets you work on Message, which
provides efficient ways to access/process the message not just a DOM
based message. The programming model of the handlers is same and the
Message handlers can be mixed with standard Logical and SOAP handlers.
I have added a sample in JAX-WS RI 2.1.3 showing the use of
MessageHandler to log messages and here is a snippet from the sample:
public class LoggingHandler implements MessageHandler<MessageHandlerContext> {
public boolean handleMessage(MessageHandlerContext mhc) {
Message m = mhc.getMessage().copy();
XMLStreamWriter writer = XMLStreamWriterFactory.create(System.out);
try {
m.writeTo(writer);
} catch (XMLStreamException e) {
e.printStackTrace();
return false;
}
return true;
}
public boolean handleFault(MessageHandlerContext mhc) {
.....
return true;
}
public void close(MessageContext messageContext) { }
public Set getHeaders() {
return null;
}
}
(end quote from 2007 blog post)
You can find a full example in the Metro GitHub repo.
What JAX-WS implementation runtime are you using? If there's a way to do this using the runtime built into WebSphere I'm certain there's a way to do this cleanly in other runtimes like Axis2 (proper), Apache CXF, and Metro/RI.
I am using the other way to reduce the memory costing, which is Message Accessor.
Instead of using context.getMessage(), I changed it to this way:
Object accessor = context.get("jaxws.message.accessor");
if (accessor != null) {
baosInString = accessor.toString();
}
Base on advice from IBM website. http://www-01.ibm.com/support/docview.wss?uid=swg1PM21151