Problem Statement

This problem is in context with development of GUI using Smartclient from Isomorphic. We were using RestDataSource which is used to post form data on the server. At server end, request processing service was taking too long (~6 minutes) to process the data. We were overriding transform response method to post process the response. And expected it to get called, but after 6 minutes when server is done processing, transform response method was never called.

Analyzing Problem's Root Cause

We manipulated the application server logic to give a dummy reponse back in time and found every thing works okay. We came to a conclusion that server taking too long is the cause of problem.

Comparison of different open source cache implementations:

I have explored and analyzed a few open source cache implementations (Oscache, Ehcache , Jboss Cache and JCS) and I found that there are various features which are common to all of them while there are a few features that specifically characterize a particular implementation. For instance, JBoss provides Tree Cache implementation that gives the user liberty to organize data, to be stored in cache.

Problem

We have a jsp page that has a HTML table and an applet.

Both components have the same source of data which is an MBean on the server. Table data is same as the data used by the applet for plotting a graph. Both components refresh themselves after an interval of time.

Since data is already fetched by the table we needed a way to avoid the call that is made by the applet.

Solution

If we set the table data in a html element (of type hidden) and somehow our applet is able to access it.

While exporting a Remote Object into JVM's RMI system using UnicastRemoteObject#exportObject(remoteObj); do not forget to unexport the remote object when you have finished and want to shutdown the VM. This is because RMI keeps tracks of objects being exported ; it spawns a Reaper Thread that tracks the live objects exported into RMI. It is non-daemon thread that keeps alive the VM until all objects have been unexported from JRMP.

Abstract

Designing a presentation tier for a 'Widget Based Web Application Framework'. Following are the list of objectives of the intended framework.

Widget Based GUI: Instead of designing legacy paged based web application, widget (component) based approach has to be followed. iGooglish kind of GUI is expected. These widgets will be used to view/edit information, displaying graphical representation and many more.

Recently we developed a web application, using SmartClient framework for client side pages, Spring for security and java classes for server side processing. 

In our application we introduced a User Preferences option so that the logged in User can have its own titles, number of search records, queries' result as of his own choices.   As there are some 20-25 different options that a User can have, we decided to  save his preferences/choices as a XML in the blob column in Oracle database.

SmartClient 6.5.1

SmartClient is a robust RIA framework with its version 6.5.1 released from Isomorphic Software. SmartClient gives one the feel of a rich and lively web application. We have put to use the only the client side support it provides under the LGPL license.

When we first began working with SmartClient things were not that rosy. Gradually as we picked up pace we understood the capabilities and offerings of SmartClient.

Problem: Setting up JMX monitoring for our tomcat application entailed setting following system properties while starting the JVM. 

Dcom.sun.management.jmxremote and Dcom.sun.management.jmxremote.port=portNumber.

We already had a setenv script in the tomcat bin directory, which we used to set other system properties needed for our application.  The script was modified to include the JMX related system properties.
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