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Chapter Interservlet Communication Servlets running together in the same server have several ways to communicate with each other. There are three major . I have a Websocket servlet and a Rest servlet. I want to inform the websocket servlet about changes in order to write these “events” via websocket to a server. hi iam new to interservlet iam familiar with servlet only i am planning to write interservlet

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In this case, your servlet should make an HTTP request to the other servlet instead of direct calls. When used interserrvlet getServletthis method can perform the same function as the deprecated getServlets. Post Your Answer Discard By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of conmunicationprivacy policy and cookie policyand that your continued use of the website is subject to these policies.

What is inter-servlet communication?

I want to inform the websocket servlet about changes in order to write these “events” via websocket to a server. Direct servlet manipulation A servlet can gain access to the other currently loaded servlets and perform some task on each.

You could achieve that by marking the EventManager as a singleton EJB by adding the Singleton annotation, and inject it to both the Rest servlet and the websocket servlet.

By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. There are three possible workarounds.


Servlet collaboration The most common, situation involves two or more servlets sharing state information. Sign up or log in Sign up using Google. Think back to the ChatServlet from the previous chapter.

Because otherwise it would have to cast each Servlet object to some class or interface that includes a saveState method, and the code for each servlet would have to be modified to extend or implement that class or interface.

Every class but the interface can remain in the servlets directory. The server may–but isn’t required to–load the named servlet and execute its init method if it isn’t already loaded.

Inherservlet servlets should be running in the same server. Example uses these methods to display information about the currently loaded servlets, as shown in Figure Session tracking see Chapter 7, “Session Tracking” is a special case of servlet collaboration.

A servlet obtains information about other servlets through the ServletContext object. Second, make sure that the servlet being cast is never reloaded. What you could do is create a third component, let’s call it EventManager for the time being, and have the Rest servlet signal changes to the EventManager. And then calling the function on the returned Servlet object. The most common, situation involves two or more servlets sharing state information.

I use JavaEE Eclipse. This method returns an Enumeration of the Servlet objects loaded in the current ServletContext. The servlet could, for example, periodically ask every servlet to write its state to onterservlet to protect against server crashes. If the invocation goes without a hitch, it prints “Saved! Interservlet communication Ask Question.


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It was written as a server for chat applets, but it could be reused unchanged by another servlet that needed to support an HTML-based chat interface.

What is inter-servlet communication?

Stack Overflow works best with JavaScript enabled. The enumeration always includes the calling servlet itself. For example, a set of servlets managing an online store could share the store’s product inventory count. Direct servlet manipulation involves one servlet accessing the loaded servlets imterservlet its server and optionally performing some task on one or more of them.

Java Servlet Programming by Jason Hunter

The Java Web Server does not perform this load. Then it calls the context’s commuication method. Notice that if the Loaded servlet used the deprecated getServlets method instead of getServletNamesit would not have had access to the servlets’ names. For each name, it retrieves the corresponding Servlet object with a call to the context’s getServlet method. There are some Servlet engine specific configurations for servlet chaining.