Barry Wilkinson and Mark Holliday, 2004 A1.1

AssignmentsPreliminaries

• Several computers are configured at WCU for the assignments. Here, terra.cs.wcu.edu will be used.

• For technical reasons, students using the WCU computers will first ssh into sol.cs.wcu.edu, and from there ssh into terra.cs.wcu.edu.

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Assignment 1

“Deploying a Simple Web Service”

AcknowledgementThis assignment is derived from:

“Classroom Exercises for Grid Services” by A. Apon, J. Mache, Y. Yara, and K. Landrus,

Proc. 5th Int. Conference on Linux Clusters: The HPC Revolution, May 2004.

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Task

• To build, deploy and test a simple web service.

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Tools

This assignment uses:

– Java 2 platform standard edition– Apache Jakarta Tomcat Java servlet

container– Apache Axis tools

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Steps

• Write the Java code to implement the web service.

• Use Axis to generate all needed Java source files.

• Compile the source files just generated.

• Create client source and compile.

• Execute client to access service.

• Extend the functionality of the service.

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ClientWeb service

Apache hosting environment

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Axis Java Web Service Facility

• Place a jws (rather than java) file in your web application directory structure and Axis will automatically find it, compile it, and deploy the methods.

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Step 1 – Implement Service

Using Java write the code for the class that provides the web service. This code is:

public class MyMath { public int squared(int x) { return x * x; }}

Save that code as a .jws (Java Web Service) file, Math.jws.

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Step 1 (continued)

Copy the .jws file to the axis directory:

cp MyMath.jws \

$CATALINA_HOME/webapps/axis/yourusername

Copying is needed so that the axis tools will be able to find the .jws file

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Step 2 Generate WSDL files

Use the Axis tools to create four Java source files from MyMath.jws using the command:

java -classpath $AXISCLASSPATH \org.apache.axis.wsdl.WSDL2Java \http://localhost:8080/axis/MyMath.jws?wsdl

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Step 2 (continued)Axis finds MyMath.jws file and creates

• Two source files each holding a Java interface, – MyMath.java and

– MyMathService.java• Two source files each holding a Java class,

– MyMathServiceLocator.java– MyMathSoapBindingStub.java

These files are put in a new package inlocalhost/axis/yourusername/MyMath_jws/

which is in /home/yourusername/WebServices/

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Step 3 Compile new source files

Compile source files generated by step 2 with:

javac -classpath $AXISCLASSPATH \localhost/axis/yourusername/MyMath_jws/*.java

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Step 4: Write Client Source

import localhost.axis.yourusername.MyMath_jws.MyMathServiceLocator;import localhost.axis.yourusername.MyMath_jws.MyMathService;import localhost.axis.yourusername.MyMath_jws.MyMath;

public class MyMathClient { public static void main(String args[]) throws Exception { MyMathService service = new MyMathServiceLocator(); MyMath myMath = service.getMyMath(); int x = (new Integer(args[0])).intValue(); System.out.println("The square of " + args[0] + " is "

+ myMath.squared(x)); }}

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Step 5 Compile Client code

Compile the client source file with:

javac -classpath $AXISCLASSPATH:. MyMathClient.java

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Step 6 Execute Web Service program

java -classpath $AXISCLASSPATH MyMathClient 4

The square of 4 is 16

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Step 7 Extend the Web Service

Add functionality to the MyMath web service:

• Add a method that returns whether a number is

even.

Modify MyMath.jws file and repeat all previous steps to test the extended web service.

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Step 8 (not in handout)Extra Credit

• For extra credit, create a second web service and demonstrate a client using two web services.

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Submission of Assignment 1

Produce a 2-4 page Word document.

• Includes how you modified the service (code and explanation).

• Show that you successfully followed the instructions and performs all tasks by taking screen shots and include these screen shots in the document. Number of screen shots is up to you but it should demonstrate your programs worked.

– To include screen shots from Windows XP, select window, press Alt-Printscreen, and paste to file.

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Submission continued

• Submit your document to me electronically using the WCU Department of Mathematics and Computer Science electronic submission system called Hermes.

PLEASE DO NOT SUBMIT BY EMAIL TO ME!!

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Hermes Submission System• Go to:

http://www.cs.wcu.edu/~hermes

• Select professor (Barry Wilkinson), then

• Select course (CS493 Fall 2004 Grid computing), then

• Select your name, then

• Select your document and select upload.

• A message is displayed as a receipt.

• Also email sent to you.

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Due Date

• 11:59 pm Thursday September 9th, 2004 unless we have system problems.