How to uninstall previous mysql server and install fresh mysql server on Linux

Uninstall

sudo apt-get remove --purge mysql-common mysql-server mysql-client


Install

sudo apt-get install mysql-server

How to develop and deploy web applications using WSO2 Developer Studio.

How to develop and deploy web applications using WSO2 Developer Studio

 

http://wso2.org/library/articles/2012/09/develop-deploy-web-applications-using-wso2-developer-studio

Introduction to WSO2 Developer Studio - ESB Graphical Editor.

          WSO2 Enterprise Service Bus is a lightweight enterprise service bus which delivers high performance. WSO2 Enterprise Service Bus is based on Apache Synapse and available under Apache Software License v2.0. WSO2 Developer Studio provides a Eclipse based SOA development environment for WSO2 products. With WSO2 Developer Studio 2.0.0 Beta, they provide a graphical editor for develop WSO2 ESB Configurations (Synapse Configurations).

         Basically 'WSO2 Developer Studio - ESB Graphical Editor' consists of two pages. One page is a visual drag and drop editor and another page is a XML editor. Visual editor facilitates users to drag and drop components from the tool palette and simply connect them to build message mediation routes graphically. Configurations of components in the canvas can be done using Properties view. Editor will generate the relevant Synapse Configuration according to the design and generated configuration is viewed in the source view page.

Design View

Source View

                 Tool palette consists of Proxy Service, mediators and Endpoints. First thing is to do is dragging and dropping a Proxy Service from the tool palette to the canvas. Then you can drag and drop mediators and endpoint according to your expectation to relevant areas of the Proxy Service figure. There is no restriction for doing this (You can add an Endpoint before adding In Sequence) since connecting these mediators and endpoints is a manual thing.


How this can help developers ?


           As the following figure depicts, mediation engine consists of Proxy Services, Endpoints, Sequences and Startup jobs. When a message is entered to the Proxy Service, the massage goes to the relevant Endpoint via In Sequence. And the response message is sent back to the client via Out Sequence. ESB graphical Editor basically follows this model. When we consider a proxy Service inside the ESB Graphical Editor it consists of areas for In Sequence, Out Sequence and Endpoints. This clear separation will lead to represent complex Synapse configurations in a uncomplicated manner.

           We can configure these Proxy Services, Mediators and Endpoints using properties view. Simple configurations like names, value types can be entered using this property view. And also this editor provides various types of dialog boxes to do some advance configurations. For example, see the following figures.

             Developers who like to develop configurations manually can use Synapse Configuration source viewer as a text editor. This source editor consists of features like Syntax highlighting, content assist etc. So this is a valuable feature in ESB Graphical Editor even though these manual changes doesn't reflect to the visual editor page yet.

         ESB graphical editor comes as an Eclipse plug in. This will be an advantage since most of the developers  are familiar with Eclipse IDE.

How To Create Synapse Configuratons using WSO2 Developer Studio - ESB Graphical Editor.

1. Install WSO2 Developer Studio 2.0.0 Beta (Installation guide).  

2. First open WSO2 Developer Studio Dashboard.

3. Create a 'ESB Config Project' which is under Enterprise Service Bus category, using WSO2 Developer

 Studio Dashboard. Give a name for project. Let's give 'Sample1'. Click finish.

4.Right click on 'Sample1' project in the 'Project Explorer' view. Then click New-> Other. You will have a

 wizard. Select WSO2->Message Mediation-> Message Mediation Features-> Synapse Configuration and

 click Next. Give a name for the file and click Finish. 

  5. You will have a 'Synapse Configuration Editor' opened. 

 6. We are going to create following Synapse Configuration.

<?xml version="1.0" encoding="UTF-8"?>

<definitions xmlns="http://ws.apache.org/ns/synapse">
   <proxy name="Sample1" transports="https http" startOnLoad="true" trace="disable">
       <target>
           <inSequence>
               <log category="TRACE" separator=","/>
               <send>
                   <endpoint>
                       <address uri="http://www.example.org/service"/>
                   </endpoint>
               </send>
            </inSequence>
            <outSequence>
                <log category="TRACE" separator=","/>
            </outSequence>
       </target>
   </proxy>
</definitions>


7. First drag and drop a 'Proxy Service' from the tool palette. 

 8. Then drag and drop a Log Mediator to the In Sequence section of the Proxy service figure. Then drag

 and drop an Address Endpoint to the Endpoint section of the Proxy Service figure. Finally drag and drop

 a Log Mediator to the Out Sequence section of the Proxy Service figure. Then connect the input and 

 output connectors of the nodes. 

 9. You can configure your Log mediators and EndPoints using Properties view. To open Properties view,

 double click on the relevant figure or right click on the figure and select 'Show Properties View' from the

 context menu. 

 10. Now we have finished the design and configurations using Design view. You can see the generated 

 Synapse Configuration for this design by clicking the 'Source' page of this editor.