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Posts Tagged ‘java’

Writing Colorful Console Output in Java

October 20th, 2013 No comments

Almost all of the Java console application I had seen were boring black background and white fonts on Windows. This can be changed using a small Java library called Jansi which is open sourced under Apache 2.0. The download link can be found at its project home. The source code is also available on Github here.

Categories: Software Development Tags: ,

Parsing Command Line in Java

October 10th, 2013 2 comments

If you develop a command line tool, you would probably need to parse options and arguments. In Java, you can use Apache Commons CLI to handle the parsing. Since I don’t write much command line program, I don’t need these tools. While reading vCO API sample, I found one command line tool called args4j which is written by Kohsuke Kawaguchi who had created the famous Hudson/Jenkins server.

How to Add Copyright Notice in JavaDoc

October 8th, 2013 1 comment

While using Netbeans IDE to generate Javadoc for a Maven project, I noticed the generated pages has a default copyright notice at the bottom of every page, say “Copyright 2013. All Rights Reserved.” Because it’s default, it does not show the name of copyright owner. To change it, I found it’s not really straight-forward, therefore it may be worthwhile to share it.

Angular JavaScript Framework: Interacting with Java Servlet Backend

September 10th, 2013 30 comments

In my last article, I introduced the Angular JavaScript framework with working samples. Among all these JavaScript frameworks, I think Angular is the first one that does it right (I can be wrong on this as my exposure of JavaScript is limited). If your project needs Web GUI for example vSphere Web Client plug-ins, it’s definitely a good choice to consider.

Securing REST APIs or Web Application With Basic Authentication

September 5th, 2013 No comments

If you implement REST Web Services, you want to secure them. The simplest approach is to use the basic authentication () with user name and password. To protect all the resources behind the REST APIs, you can simply implement filter as introduced in Java Servlet 2.3 ().

REST API Service Made Easy with Jersey Framework in Java

August 25th, 2013 16 comments

Because REST APIs are easy to get started with, I see more products are adopting it for remote management APIs. To implement the REST on the server side, you can use different programming lanaguages and frameworks. In Java, you can use the Jersey framework which is a reference implementation of the JAX-RS (JSR 311 & JSR 339).

Unit Testing with JUnit 4 in Java: Quick Introduction and Simple Samples

August 5th, 2013 1 comment

Unit testing is an important part of software development because it helps capture bugs before it moves on to QA or even customers. However, it’s not part of the end product therefore whatever you invest in unit testing will not yield any direct result but indirect result in better quality of your product. So at one side, you want to do it more for better quality; on the other side, you want to minimize it for less investment. It’s therefore a tricky trade off for best ROI. For more discussion, see here.

Java Native Access: What, How, and Performance Comparison

July 1st, 2013 No comments

While trying the libvirt Java binding, I came to know Java Native Access (JNA) which is a great alternative to Java Native Interface (JNI). As it’s said, no one can claim to know all about Java after 1.5. It’s now 1.7 (although majority of us are still with 1.6) and it’s even less likely. I am no exception.

Understanding Libvirt and APIs For VMware Professionals

June 26th, 2013 No comments

As discussed in my previous post, Libvirt is an open source project for managing hypervisors. With the increasing popularity of Openstack, it’s important to get familiar with KVM as an alternative virtualization platform to commercial products like vSphere and Hyper-V.

To use KVM, you don’t have to install Openstack – you can just install KVM as a standalone product as described in my previous post. In that, it’s pretty much like VMware Player or Workstation. In terms of maturity, KVM is pretty solid and way ahead of Openstack which is also improving quickly since last year with many commercial vendors jumping in.

Managing KVM with Libvirt In Java: Step by Step Tutorial

June 23rd, 2013 7 comments

As mentioned earlier, I got the KVM instances running on my compute cluster after installing the Openstack. I’ve been curious on KVM management APIs, so I took some time to give it a try. In the following, I’ll detail on how to set up environment and get your first HelloWorld type of Java code working.

Categories: Virtualization Tags: , ,

GIT Commands Using Java APIs

March 26th, 2013 9 comments

In previous posts, I’ve covered an Java API called JGIT for working with GIT. Besides the low level APIs, JGIT also supports high level command line like interfaces. If you know how to use the GIT command line, you can use the APIs. Note that it’s different from calling GIT commands or any other commands from Java code.

Here is a sample code I wrote to try out the APIs. Give it a try and you will like these high level APIs.

Categories: Software Development Tags: ,

How to Use GIT Java APIs to Diff Two Different Files

February 11th, 2013 1 comment

In my previous post, I introduced a sample showing how to use JGIT Java APIs to diff two versions of a same file in repository. The JGIT Java APIs can do more than that – it can actually diff two text files that are not even controlled by GIT.
Here is a short sample code on how to do this. Again, it’s not the main use case for the JGIT APIs. After all, it’s mainly for GIT source control system itself. You can always use other diff APIs for this purpose. However, if you already have JGIT included, this can be handy.

Categories: Software Development Tags: ,

How to Use GIT Java APIs to Diff Different Versions

February 3rd, 2013 5 comments

Last week I introduced the JGIT Java API with a simple sample illustrating how to read content from HEAD. If you have multiple versions of a source code or text file, you may want to see their differences. An easy tool for this is the standard diff.

The JGIT Java API has built-in support for you to generate diff between any two versions of a file, be it a source code, properties file, XML file, or any other text files. Here is a sample that shows how to do this.

Categories: Software Development Tags: ,

How to Read GIT Repository Using Java APIs

January 27th, 2013 14 comments

GIT is a source code control system created by Linus and others for managing Linux kernel development. It becomes one of the most popular version control systems especially in the open source community. Most developers use command line or the plugins to IDEs like Eclipse, NetBeans. I think even Microsoft VisualStudio has add-on for connecting to GIT, but I haven’t checked it.

Simple Logging in Java Application

January 21st, 2013 3 comments

Logging is a common requirement for application. In Java world, there are a few frameworks, the first and the most famous of which is the log4j from Apache foundation. Java included its own logging APIs afterwards. You can find many discussions which one is better in terms of use of use, flexibility, and performance. To reconcile the two APIs, a common abstraction called Simple Logging Facade for Java (SLF4J) was created. As SLF4J works with both log4j and Java logging, you can switch between them easily (in theory).

Categories: Software Development Tags: ,

Massive Scheduling with ScheduledExecutorService in Java

January 14th, 2013 2 comments

If you need to do certain things at certain points of time or intervals, you need scheduling capability. Don’t confuse the scheduling with multi-threading even though you can use multi-threading for scheduling but they are not equivalent. You can use single thread for many different tasks. Simply put, threads are executors, and tasks are jobs to be done by executors.

Developing Web Application with JQuery and Java Servlet

December 27th, 2012 6 comments

It’s been a while since I touched Web application development in 2009. Before the VMworld 2009, I created a simple Web Application for the keynote that collected the names and email for a raffle to go back stage with the famous foreigner. That Web application was so simple that it’s built using Java Servlet with a static home page. It’s hosted with Terremark (part of Verizon now) Enterprise cloud.

Getting started with Hadoop: My First Try

June 18th, 2012 5 comments

Given the growing popularity of Hadoop, I decided to give it a try by myself. As normal, I searched for a tutorial first and got one by Yahoo, which is based on Hadoop 0.18.0 virtual machine. I knew the current stable version is 1.x, but that is OK because I just wanted to get a big picture and I didn’t want to refuse the convenience of ready-to-use Hadoop virtual machine.

What Does Oracle-Google Case Mean For Cloud Computing?

May 31st, 2012 No comments

As a software professional using Java since its very beginning, I have been following the case regarding Google’s using Java APIs in its Android OS. I don’t want to repeat what has happened so far because you can find these updates by searching the Internet. All I want to say is that the case is pretty educational not only on the technology itself but also on the legal side like patents, copyright.

Java Code Style and Formatter

March 2nd, 2012 No comments

While writing samples for my book VMware VI and vSphere SDK, I developed a Java code formatter within Eclipse. Although there are several built-in formatters like Java conventions, Eclipse, and Eclipse 2.1, I still decided to create my own partially due to the special requirements by Prentice Hall, but mostly due to my personal flavor for Java code.