How to: web service mock with SoapUI

Introduction

A lot of organizations use web services (WSDL) for system integration. Often those services are developed alongside the application that uses those services. Instead of waiting for those services to be developed, the application which consumes the web service can develop a mock implementation of the service to test against.

Several strategies

There are several strategies for developing mock services from a WSDL. One of these strategies is using SoapUI. SoapUI is able to consume the WSDL and generate a mock service from it. After the mock service is created, the application in question can consume this mock service and start using it.

The advantage of mocking this way, is that the application makes a full HTTP network round-trip when calling the respective service. All relevant components within the application (WSDL client, parsing the response message) are covered.

Instead of describing how to mock a web service using SoapUI, I created a small screencast demonstrating this. The screencast can be found here: Web service mocks with SoapUI

I think this screencast is more clear and easier to follow than written text. To be effective I keep my screencasts shorter than 5 minutes. Descriptive subtitles are also included. Please let me know if you like this format.

Final thoughts

Besides speeding up development, mocks/stubs may also be used to put the system in a known state which enables automatic integration testing.

Reasons for IntelliJ

Introduction

I often get the question why I use Intellij in favor of another IDE, in this case Eclipse. Most of the time I answer that question by demonstrating some features of IntelliJ and showing how integrated everything is. This got me thinking about what are the actual reasons that I use it. This post will try to make that clear and help others decide if the switch is worth it or not.

Some background

I had been a long time Eclipse (7+ years) user before I made the jump to IntelliJ. Before Eclipse, I worked with Rational Application Developer, WSAD, JBuilder and Visual Age for Java. Compared to these IDE's, Eclipse was a joy to use. I could, for example, generate getters and setters, which was not possible in one of the older IDE's (we are talking about more than 10 years ago). Although I quite liked Eclipse I always thought there were some deficiencies. Mainly in the following areas:

• Why was there no core functionality bundled with the standalone Eclipse variant? For example Subversion and Maven integration.
• Why was it always painful to setup an Eclipse version to your liking with all the required plugins? With every new version I spent always nearly half a day setting up my IDE. This is unacceptable I think. The more plugins and functionality the harder it got.
• Updating to a new version was sometimes painful. Plugins that stopped working for example.
• I never quite liked the concept of a workspace. I already organize my projects on disk so I do not need a workspace concept.
• I did not like the idea of different perspectives. Why do I have to think about the context I am working in? For example: working with Java and Flex in one project. When I am in the Flex perspective my Java code completion/refactoring did work in Java files. Context should be file or even fragment driven.

Please note that the above are personal opinions and may vary between users. Despite of this I was quite productive in Eclipse and liked the performance of it. Also note that these observations are from a couple of versions back. Things may have changed.

Around 2007/2008, a colleague of mine introduced me to Intellij, I think it was version 7 back then. My first reaction was I don't need another IDE. He showed me some features, like code inspections, and I said I would give it a try. My main obstacle back then was the price. That year I also gave a talk at the Dutch Java User group conference. Every speaker received a free IntelliJ license from JetBrains. I then decided I would give it a try. After the first two or three days I thought I would give up. I had to learn all new key-bindings and I was less productive. I persisted and after a week or so I begun seeing the benefits of it. After version 7 I upgraded to 8, 9 without any problem. Things could be different. At the moment I work with the latest version, 12.1 EAP. Below are some of my reasons why I do most (if not all) of my development work in IntelliJ.

Major features

• It is an integrated solution. I do a lot of different development work with a lot of different technologies, for example: Java, HTML/CSS/JavaScript, Android, Grails/Groovy, Flex, Subversion, Git, Maven, Ant etc. This is all possible with IntelliJ out-of-the box. There is no need to install separate plugins, which saves me a huge amount of setup time. Just download and install it and you're good to go.
• The editor itself. I invest heavily in knowing all the shortcuts. By knowing all the shortcuts I can code very fast. The instant code completion (not having to hit Ctlr-space all the time) is a joy to work with. Just type a couple of characters and hit Tab to complete the code. When I generate code, the cursor almost always is in the correct position to begin typing again. No need to touch the mouse or whatever.
• Code inspections and analysis tooling build in. I find it important to keep my code clean and bug free. The build in inspections and the ability to auto solve them are a really nice addition. Besides this you also have a dependency matrix viewer to get a quick overview of the dependency structure of your application and a duplicate code checker.
• Live templates. Live templates greatly increase coding speed. To make the most of it, I highly recommend creating your own templates. This is very easy. Just select a piece of code and select Save as Live template from the Tools menu. Press Ctrl/Cmd+J to view the live templates.
• Maven/Gradle integration out of the box. Just import a Maven project and Intellij knows the modules, dependencies etc. You can easily generate a dependency diagram from the Maven pom file to view all the dependencies at a glance. See figure 1 for an example of the Maven dependency viewer.
• Some handy tools. I often use the database editor and the RESTful web service test utility. The database editor has code completion in SQL and table creation. With the RESTful web service tester you can easily test HTTP services. The response can then me immediately saved and formatted as JSON or XML.
• Powerful refactorings and structural search & replace. IntelliJ knows a lot about my code. For example in Android: when I rename an image in the values/hdpi folder, it also renames the corresponding images in the mdi and xhdpi folder but also updates my XML views and code references to that image.
• Tasks and Contexts. I use IntelliJ in combination with YouTrack (there are more issue trackers that IntelliJ can integrate with). It is really easy to start working on an issue. IntelliJ creates a new context that tracks the files that belongs to that specific issue. I can mark the issue in progress and when I commit my changes it takes the comments from the context and uses this as the commit comments. It also changes the status of the issue to resolved when done working on the issue. All from within the IDE itself, no need for context switching.

Figure 1: Maven dependency viewer

Smaller features

And then there are the smaller but just as important features which increase my productivity:

• Stacked clipboard. You can have multiple entries in your clipboard. Just hit Ctrl-Shift-V to show the clipboard stack.
• Column mode in the editor. This comes in handy when working with fixed structure files like CSV for example.
• Darcula theme. This is one of the best dark themes I encountered. A dark theme is especially useful when coding in the evening with the lights dimmed. It is less stressful for the eyes I think. See figure 2 for an example of the Darcula theme.
• Stack trace analyzer. Just copy a stack trace from the clipboard and IntelliJ analyses it and matches it with the code to easily navigate to the problem at hand.
• Unit test and coverage integration.
• And many more.

Figure 2: IntelliJ Darcula theme

Final thoughts

This article describes the reasons why I use IntelliJ as my primary development tool of choice. Please note that this is my personal opinion. Also, this is obviously not an exhausted list. I would like to hear from you why you choose IntelliJ.

Evaluating new frameworks, libraries and technologies

Introduction

New frameworks and libraries are developed so fast it is nearly impossible to evaluate all of them. This can make it hard to judge whether a particular technology is worth investing (time) in. This post gives you some tips which may help when evaluating new technology.

Conceptual level

Although there are many different libraries and frameworks, most of them can be grouped based on some conceptual differentiation. The following concepts may help to give an idea of this conceptual differentiation:

• Component based frameworks
• Request/response based frameworks
• Object Relational Mapping
• Map-reduce
• Key-value stores
• Messaging
• And many more... 

When evaluating a specific technology it helps to identify to which concept or concepts it belongs. Before further analysis of a particular technology, make sure you understand the concepts. Without this understanding it is almost impossible to do an objective analysis. Understanding these concepts requires an investment in time. Usually in the form of reading, watching presentations, experimenting, training and talking to others. Understanding the concepts will make it easier to objectively evaluate a particular technology.

Simpler is usually better

One of the key actions in evaluating a particular technology is to determine if and how it satisfies the given requirements. A lot of frameworks and libraries provide a 1 minute introduction, a 5 minute guide, a 30 minute tutorial and more. I really like these sorts of introductions since it usually gets you up-to-speed quickly. Besides getting up-to-speed quickly, a more important factor is the complexity of the given solution. I really like the idea of "Make things as simple as possible, but not simpler".

The starter guides, as mentioned above, present the readers with a relatively simple case or problem to demonstrate the key features of a given technology. To find out if a certain technology will fit I suggest to look at the complexity of the solution for the cases in the introduction guides.

In my opinion, if the solution for a relatively simple case or problem is complex and not easy to understand, how can a solution to a more complex problem be easy to understand? This complexity comes of course in various flavours:

• How much code do I need to write to get even the simplest things done?
• How many classes do I need to extend? 
• What and how much configuration should I write?
• What is the quality of the documentation?
• How can I easily test my solution?
• Etc.

If the solution to a simple problem is indeed simple and easy to understand, it is worth investigating more time to find out if the technology satisfies your requirements. If the solution to a simple problem is not simple and not easy to understand, think long and hard before investing more time in it.

Conclusion

New frameworks and libraries are developed so fast it is nearly impossible to evaluate all of them. To speed up the decision process make sure you understand the technology at the conceptual level. Once you understand the conceptual level, experiment with the technology using introduction guides if they are available.

If, from those introduction guides, solutions to a given problem are simple and easy to understand, it may be well worth spending more time investigating the particular technology for more complex problems. If not, proceed with care.

As always, your mileage may vary.

Sample generated melodies

Based on some questions, I uploaded a couple of sample melodies in MP3 format which are generated by my genetic algorithms melody generator. The generated sample melodies can be found here: http://code.google.com/p/melodycomposition/downloads/list.

The original article of the melody generator can be found here: Melody generator

Kinect within VMWare

Recently Microsoft announces the availability of the Kinect 1.6 SDK. One of the big enhancements in this release is the support for the Kinect device within a virtual machine (VMWare or Parallels)!

For a client we developed a Kinect application which was shown at the Dutch Floriade festival. More details about this project in a next post.

The problem with the old Kinect SDK was the inability to use the Kinect within a virtual machine. Because of this I had to create a bootcamp partition and install Windows on it just for the sole purpose of Kinect development. The 1.6 SDK solves this!

Below are the results of my tests with the Kinect within VMWare. I used the following system configuration to test on:

1. MacBook pro 2011 with 2Ghz core i7 and 8GB RAM..
2. OSX Mountain Lion.
3. VMWare Fusion 5 running Windows 7.
4. Visual Studio Express 2012.
5. Kinect 1.6 SDK.

First I tested the above setup with the Xbox Kinect. This did not work which I more or less expected since Mircosoft wants to push the Kinect for Windows for Kinect development.

Next I tested was the Kinect for Windows. After I connected the device I started the Shape Game sample application. The device was found and worked immediately! I also tested the Kinect with our own application and this also worked as expected.

Ont thing I noticed was that both applications did not run as smooth as when I ran the application under bootcamp. After examing my virtual machine settings I noticed I had given it only 1 cpu core (out of the available 8). This could be the problem. When I changed the maximum number of cpu cores the virtual machine may use to 4, things ran much smoother. There was no noticeable difference when running within a virtual machine or bootcamp. 

For more information about the 1.6 SDK see: http://msdn.microsoft.com/en-us/library/jj663803.aspx#SDK_1pt6_M2.

Conclusion
The new Kinect 1.6 SDK does work within a virtual machine if the Kinect for Windows is used.

IntelliJ SSR: replace constructors

Suppose you have a large codebase which uses a particular class named SomeClass (nice descriptive name :)). SomeClass has one constructor:

public SomeClass(String a, String b, String c, String d) {
    // Do something
}

This constructor is used at various places in the codebase.

At some point in time an update to SomeClass is made which introduced another constructor:

public SomeClass(String a, String b) {
    // Do something
}

Lets assume you want all calls to the 4 argument constructor to be replaced by the 2 argument constructor. The arguments of the 4 argument constructor should be used in the 2 argument constructor in the following way: new SomeClass(1, 2, 3, 4) becomes new SomeClass(3, 1).

See the following example:

public class UsageOfSomeClass {
    private SomeClass instance_1 = new SomeClass("a", "b", "c", "d");
    private SomeClass instance_2 = new SomeClass("d", "e", "f", "g");
    private SomeClass instance_3 = new SomeClass("h", "i", "j", "k");

    public static void main(String[] args) {
        SomeClass someClass = new SomeClass("1", "2", "3", "4");
    }
}

Should become:

public class UsageOfSomeClass {
    private SomeClass instance_1 = new SomeClass("c", "a");
    private SomeClass instance_2 = new SomeClass("f", "d");
    private SomeClass instance_3 = new SomeClass("j", "h");

    public static void main(String[] args) {
        SomeClass someClass = new SomeClass("3", "1");
    }
}

You can achive the following for an entire codebase with one single structural search and replace action. Use the following templates to achieve this:

Search template: new SomeClass($arg1$, $arg2$, $arg3$, $arg4$)
Replace tempalte: new SomeClass($arg3$, $arg1$)

Hit find and Replace All. Thats it!

IntelliJ: HTML and structural search and replace

I was asked to do some quick fix on some website. The website used a lot of table structures for laying out the page. To give an impression, the page had more than 50 tables each with 4 columns and 20+ rows.

There was no external CSS used. All styling of the tables was done with attributes or inline style elements. The styling was also not consistent throughout the page so each table looked slightly different.

Here is an example:

<table>
    <tr>
        <td width="200px">Some text</td>
        <td width="221px">More text</td>
        <td width="300px" height="100px">Example</td>
        <td style="width: 210px;">HelloWorld</td>
        <td style="width: 190px;">More text</td>
        <td id="test" style="width: 222px;"></td>
        <td id="test2" class="right" style="width: 200px;">Java</td>
    </tr>
</table>

Without rewriting the whole site at once I wanted to remove all the inline styles so I could use css to style all the tables the same. That at least looked more attractive in the short run while in the long run we could focus on a complete redesign of the site.

The first thing I wanted to do was replace all the td elements with inline styling with plain, empty td elements. As written in my previous posts, IntelliJ's structural search and replace features fits this use case nicely.

In the structural search and replace dialog I used the following:

Search template:

<td $width$="$value$" $style$="$value$">$text$</td>

Replace template:

<td>$text$</td>

In the Edit variables dialog I specified a minimum count of zero for the $width$, $style$ and $text$ variable. The $value$ variable has a minimum count of one. For all variables I used a maximum count of one.

The template searches for all td elements with zero or one width or style attributes (or both) and with or without text. The replace template replaces the td found with the search template in a plain td. The output of the HTML after the search and replace is run is:

<table>
    <tr>
        <td>Some text</td>
        <td>More text</td>
        <td>Example</td>
        <td>HelloWorld</td>
        <td>More text</td>
        <td></td>
        <td>Java</td>
    </tr>
</table>

After this replacement I could just insert the appropriate CSS and style all tables consistently. Without structural search and replace I think such scenario's take considerably longer to execute.

Hope you enjoyed it.

If you have other interesting structural search and replace use cases please share them.