web service in rad6

8/6/2019 Web Service in RAD6

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Introduction

This document gives the step by step process for developing, deploying and testing of a

simple Webservice in RAD 6.0 IDE.

We can create the webservice in two ways

1) Bottom Up or Stub scenario : create a Web service from a Java bean or a EJB or aDADX.

2) Top Down or Skeleton scenario : create a Web service from a Web ServiceDescription Language (WSDL) file

Depending upon the server and the chosen run-time, the artifacts that the Web services

wizard generates may vary. The end result is a deployed Web service on a server.

If a vendor deploys a Web service and you would like to create a client to use it, the

Web service client wizard does this by starting with the WSDL file.

A Web service can be based on a number of different types including a Java bean,

Enterprise Java Bean (EJB) component, DADX document, and so on..

Creating WebService From JavaBean

We can start at different points in the wizard and create a Web service using different file

types. One start point is with a Java Bean. The Web services wizard would then generate

the Requestor-side files including the proxy bean, the WSDL file, and Provider-side files.

This is known as the Bottom Up scenario

Bottom Up Web services scenario


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Creating a Webservice From WSDL File

We can also start with a WSDL file and generate the Requestor-side artifacts and the

Provider artifacts including a skeleton bean with the WSDL operations. The

implementation is left to you to fill in. This is known as the Skeleton or Top DownScenario.

Top Down scenario

Web Service Deployment

When deploying a Web service, your choice of run-time and server affects both the

chosen J2EE specification level, as well as the files generated. WebSphere Application

Server V6.0 supports the J2EE 1.4 specification. The concept of Web projects being

deployed to an EAR file exists for WebSphere Application Server. Web services

information for J2EE is stored in a file called webservices.xml.

Suppose if we create a webproject named MyWSProject then the corresponding EAR

project is named MyWSProjectEAR.

If we are creating a webservice in Bottom Up scenario,In this case several file types

have been generated including deserializer, serializer, and helper files. These files

are used to convert the incoming XML message to Java language and outgoing Java

language to XML. There is also a SEI file which holds all the operations in the Web

service. The client proxy is generated using this file. A WSDL file is generated into the

Web Content directory. This contains information about the Web service that has just

been deployed to the server. The WSDL Test Clients use the WSDL file to test theservice directly. Rational Application Developer provides the Web service Explorer which

you can use to test the service.


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Deploy the service to the EAR and deploy the EAR to the server

Deploying the Web services using the Web services wizard. A number of files are

generated to facilitate the serialization and deserialization of the messages to and from

the service. Information is also added to the webservices.xml, web.xml, and

x_mapping.xml. This information describes the deployment of the service. This follows

the J2EE 1.4 standard. At this point all the information about the Web service has been

deployed to the EAR. The EAR has then been added to WebSphere Application Server.

Generating the Client

To generate a client, select the checkbox next to the corresponding label that says

generate proxy on the first page of the Web services wizard. Another way to generate a

client is to start with a WSDL from the service. This is known as the Client scenario .In

this case it is assumed the service has already been deployed. The Web services wizard

creates a Web project called MyWSProjectClient and a new EAR file that contains this

project. Again there are serializer, deserializer, and helper classes. The key file that the

test facilities focus on is the proxy file.


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Example of HelloWorld Web Service using Bottom-up approach

To create a new Dynamic Web Project in RAD6.0

Go to File->NewOther


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Select Dynamic Web Project

Click Next, then enter the name of the Dynamic Web Project

Enter the project name as FirstWSproject


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Click Next

Click Next


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Click Finish and click Yes to open in J2EE perspective otherwise select No to open in

java perspective.

Now we can see two folders created in Package Exoplorer view,namely

FirstWSProject and FirstWSProjectEAR


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To create a java class, go to FirstWSProjectjavaSourceNewClass

Give the package name as com.wu.firstws and give the class name as HelloWorld and

click Finish


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Add a method sayHello() in the class HelloWorld.

To create a Web Service right click on HelloWorld.java class goto New->Other


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Select Web Service in New Window. click Next

In the Web Services window check the check boxes as shown in below figure.


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Click Next and browse HelloWorld.java file from that particular package structure

Click Next


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Click Next

Click Next


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Click Next

Click Next


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Click Next it will take some time to generate the Client

Click Next


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Click Finish and now WebServices Explorer window will be opened.

Click on sayHello() in the left panel where we can see the endpoint and the user defined

methods


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Enter name in Inputs window against the name label in the text box.

Click on Invoke button. The result will be displayed in Result window.


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The folder structure looks like the below.

A file HelloWorld_SEI.java is created in the same folder where HelloWorld.java resides.

A HelloWorld.wsdl is created in WEB-INF->wsdl folder which gives the details of the

webservice which is exposed like the name of the method, SEI, port etc.


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Client folder structure looks like below.

HelloWorld, HelloWorldProxy, HelloWorldService, HelloWorldServiceInformation,

HelloWorldServiceLocator, HelloWorldSoapBindingStub are the files created in the client

project.

Some jsps are also created which can be used for testing the webservice.

web service in rad6

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