I'm sure many of you are aware that you can override the connection string settings in your DataAccess layer of your web application with connection string settings in your Web.Config. We found this out recently and found it very useful in an intranet application at work recently. However this week one of the other developers required that he could override a setting the BusinessEntity layer of his application from the App.Config in the console layer.

A quick chat with Mr Google didn't turn up a solution for this, so with this in mind all three of us quickly tried to return a working solution. I'm going to try to give an example of what we did, incase it something others may find of use. First we create a solution with two class library projects within it. The first will simulate the DataAccess layer and the second will simulate the BusinessEntity layer in an application. In the BusinessEntity project we will create a reference to the DataAccess project.

Starting with the DataAccess project we will add an App.Config file by creating a setting called "MySetting" in the Settings tab of the project Properties. The setting scope will be set to Application.

This creates a new sectionGroup called applicationSettings and a new section in the App.Config file and places the new setting in their too.

          <?xml version="1.0"encoding="utf-8" ?>
<configuration> <configSections> <sectionGroup name="applicationSettings"
type="System.Configuration.ApplicationSettingsGroup,
System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="Playground.ConfigurationOverride.DataAccess.Properties.Settings"
type="System.Configuration.ClientSettingsSection,
System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
requirePermission="false" />
</sectionGroup> </configSections> <applicationSettings> <Playground.ConfigurationOverride.DataAccess.Properties.Settings>
<setting name="MySetting"serializeAs="String">
<value>Setting in DataAccess</value> </setting> </Playground.ConfigurationOverride.DataAccess.Properties.Settings>
</applicationSettings> </configuration>
        

Next we will add a simple class to the DataAccess project with a single static method that will return the value of the setting we have just created.

          
            using System; namespace Playground.ConfigurationOverride.DataAccess
{ publicstaticclass SettingsHelper
{ publicstaticstring GetMySetting()
{ return Properties.Settings.Default.MySetting;
} } }
        

Next we will create anothe simple class, SettingsGetter, in the but in the BusinessEntity layer this time. It will just return the value returned from the SettingsHelper class in the DataAccess layer.

          
            using System; namespace Playground.ConfigurationOverride.BusinessEntity
{ publicstaticclass SettingsGetter
{ publicstaticstring GetDataAccessSettingValue()
{ return DataAccess.SettingsHelper.GetMySetting();
} } }
        

protectedvoid Page_Load(object sender,
EventArgs e) { uxSettingsLabel.Text = Playground.ConfigurationOverride.BusinessEntity.SettingsGetter.GetDataAccessSettingValue();
}

...and run the application, and allow the Web.Config file to be created. The value of the setting in the DataAccessApp.Config file should be displayed.

More to follow soon...

As part of the preliminary research and design process for a prospective new project at work one of the requirements will be for the application to provide a webservice that can be consumed from a third party's Java application.

So without further ado a quick .Net webservice was nocked up in C# with a single WebMethod. The WebMethod would return a formatted string containing within it the value passed in as a string parameter. The Webservice was deployed to localhost and tested using the simple webform test that is present on a local instal.

All good so far.

Next is to build a small Java web project that can consume the webservice. So having never written a Java application before, it's a quick trip to see Mr Google for a working example of how to call a webservice from Java. ( See My First Java App ) Google thankfully turned up David Hobbs' example "How to consume an ASP.NET webservice from Java via SOAP" on CodeProject. After a an hour or after nocking up a quick Java webpage with an embedded applet that will call the webservice and display the result, it should be a case of running it and seeing it work like clockwork.... After all the whole idea of a webservice is to platform unspecific, isn't it?....

Well, I shouldn't really have expected miracles, should I? After a whole afternoon of checking and double checking that the code was correct and using a free trial of ExamDiff Pro to ensure that XML that the java code was out putting was exactly what the XML that the server was expecting to receive I came to the conclusion that it must be something perculiar to our network. The XML output was identical except for the physical value of the parameter.

So at the end of the day I was at a loss. I'm not sure if it is an error in the code, or if the webservice expects different XML than what the description page offers up. Or if there is a network security issue which isn't allowing communication between the two applications. One of my .Net Windows applications calls a .Net webservice which is built in the same way as this test one perfectly, and has done for the last year! Event the third party representative was at a bit of a loss.

So I am at a bit of a loss with this one. May be a fresh look in a new week will shed some light. Who knows? If any one else has come accross this issue, and resolved or not resolved it, please post and let me know your findings!

Postscript: #1
I have just noticed on the botttom of David's CodeProject artical the following:

Notes
Some Java Virtual Machines (like the Microsoft one) only allow you to make a socket connection to the same machine that hosts the Java class files. Therefore, if you're using an applet like me, you will need to host the Java class files on the same machine where the webservice resides.

I wonder if this has anything to do with the problem... Oh well, maybe tomorrow I'll waste another fruitless afternoon trying to find out!! ;-)

Postscript: #2
Well after further investigation I haven't managed to determin the fault, but today we tried a different approach and used the "Web Service proxy" object from the Business Tier > Web Services category in the New Gallery.

We then followed the wizard and let it generate the code. The outputted code was tested and hey presto!!

So I guess this topic is closed for me now!