Java API for WebSocket is a new JSR to Java EE 7. It provides a stardard Java API for creating WebSocket applications. This gives web applications the ability to push data.
In Java EE 6 samples, we added a chat room sample to illustrate how to use of Servlet 3.0 asynchronous operation. In that sample, the servlet code did the following:
keep track of AsyncContext in a Queue
create a thread to...
In the process of Java development, programmers may come across complex set operations and Java alone is not powerful enough to easily handle such problem. Dynamic calculation script is good solution. In this post, I'll introduce how to conduct such computation in a simple way.
JSR 356: Java API for WebSocket provides a standard Java API for creating WebSocket Applications. The specification provides an API for...
Expression Language (EL) was first introduced as part of JSTL 1.0, was then moved JSP 2.0 and was unified with JSF 1.2 in JSP 2.1. In Java EE 7, EL is a new separate JSR, JSR 341. Many new features are introduced in EL 3.0.
This blog shows how to use new following new features of EL 3.0:
Lambda expression (section 1.20 of EL 3.0 spec)
The new operator ; to separate...
Asynchronous operation was introduced in Servlet 3.0. ServletRequest#startAsync is used to put the request into asynchronous mode. A thread need to be created implicitly or explicitly (see here for an example).
Servlet 3.1, JSR 340 includes clarifications in asynchronous area. Besides Servlet 3,1, Concurreny Utilities for Java EE 1.0, JSR 236 is introduced in Java EE 7. JSR 236 provides a...
Asynchronous operation is supported in Servlet 3.0. I have discussed startAsync in my previous blog, startAsync in Servlet 3.0. In this blog, I will discuss AsyncContext#complete. The javadoc of AsyncContext#complete has the following:
Completes the asynchronous operation that was started on the request that was used to initialze this AsyncContext, closing the response that was used to...
Servlet 3.1 Specification (JSR 340) is almost ready for the release. One of the new features is the support for protocol upgrade.
HTTP protocol upgrade was introduced in HTTP 1.1 (RFC 2616):
The Upgrade general-header allows the client to specify what additional communication protocols it supports and would like to use if the server finds it appropriate to switch protocols. The server MUST use...
Acteur - a framework for building scalable, asynchronous web applications using Netty + Guice with an interesting programming model
In report development, we may need to present the data from multiple databases in one report, such as data from MSSQL database for CRM and Oracle database for ERP. If the reporting tool like iReport only supports single data source, then we need to consolidate the multiple data sources into a single data source.
The Crystal, BIRT, and other so-called reporting tools for multiple data source can...
The data computation layer of Java aims to reduce the coupling between data persistent layer and the application layer and shift the computational workload from them. In this survey, 5 data computation layers of Hibernate, esProc, SQL, iBATIS, and R language are tested and compared on the basis of the below metrics: maturity, low coupling, scripting, integration, UI friendliness, performance, complex computation, support for big data, non-database computation, cross-database computation, and convenience for debugging.
Big data will fall into the pitfall of failure. But why big data will fall into the pitfall of failure? It is because the current big data only provides the solution for data storage and query. It lacks a good solution for business analysis to enhance the competitiveness, which is the most crucial. How to avoid the pitfall?
This brief blog entry explains the Mojarra bug triage process, and
shares some tips for maximizing the chances your bug will be quickly
fixed and find its way into a release.
Over the last few years we've been busily writing the latest and greatest version of Magnolia. After all of this focus on new and (we hope) great, it seemed like time to focuse on something old and great.
If you are old enough to remember the ZX Spectrum, the Commodore 64 or their various competitors, or if you like any kind of games, please keep on reading.
You might have heard of the qaop...
When we started building our first Java application, at my company Amway Corp, many years ago;
we learned our first lesson.
In spite of all the formal training we received, in spite of all the literature at our disposal;
we still needed help with our Java development on a regular basis.
Where would this assistance come from?
At the time, we had no in-house Java subject-matter experts.
Learning Java (or any programming language) can be a great challenge.
Any group of developers, learning Java, will bring with them a variety of backgrounds and experiences.
In our case, our first Java project began with developers that had COBOL language experience.
Our second Java project, began with developers that had RPG language experience.
Even though COBOL and RPG don't "look" like Java,...
Tuning Java code presents many challenges and addresses several goals.
One of these goals is to make the application "run faster".
Recently, our end-users were getting multiple-second response times from our web application's home page.
This was unacceptable.
We were asked to see what we can do to make the web application "run faster".
We began by looking at the usual suspects... database access...
We thought we'd get to know a little more about the author!
Servlet 3.1 Specification (JSR 340) and Java Authorization Contract for Containers (JSR 115) MR3 are almost ready for release. Besides "*", the role-name "**" is introduced in the above two specifications.
In a nutshell, "*" means any role defined in web.xml and "**" means any authenticated user.
Prior to Servlet 3.1, web containers use proprietary mechanisms to add security-constraints for any...
Servlet 3.1 Specification (JSR 340) is almost ready for the release. Several new security features have been added in this version of Servlet specification.
In this blog, I will explain one of the security features, namely deny-uncovered-http-methods.
Let us take a look at a simple security-constraint in web.xml as follows:
<web-app xmlns="http://www.w3.org/2001/XMLSchema" ...
Servlet 3.1 (JSR 340) is almost ready for the release. One of the new features is the support for non-blocking IO. ReadListener and WriteListener are introduced to allow non-blocking processing in Servlet.
Non-blocking IO can only be used in async (defined in Servlet 3.0) or the upgrade mode. We can set the async in a servlet with @WebServlet annotation.
In this blog, we will illustrate the use...