Transcript Assignment 1 “Deploying a Simple Web Service” This

Assignment 1
“Deploying a Simple Web Service”
A1.1
Task
• To build, deploy and test a simple web
service.
A1.2
Tools
This assignment uses:
– Java 2 platform standard edition
– Apache Jakarta Tomcat Java servlet
container
– Apache Axis tools
A1.3
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.
A1.4
Web service
Client
Apache Tomcat hosting environment
A1.5
Step 1 – Implement Service
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.
A1.6
Step 1 (continued)
Copy the .jws file to the axis directory:
cp MyMath.jws \
$CATALINA_HOME/webapps/axis/yourusername
%CATALINA is an environment variable specifying
the path to the home directory of the Apache Tomcat
java servlet container.
A1.7
Axis Java Web Service
Facility
By placing your Java code as a .jws file in
your web application directory structure,
Axis will automatically find it, compile it,
and deploy the methods.
A1.8
Axis Java Web Service
Facility (cont.)
The service is now deployed and can be
accessed remotely through it’s URL:
http://yourserver.yourdomain.edu
:8080/axis/yourusername/…
Example
http://www.coitgrid0.uncc.edu:8080/axis/abw/MyMath.jws
A1.9
• However, a client cannot access the
service without all the code needed
handle the SOAP messages, i.e. the
stubs and associated files.
A1.10
• Can use Java service code as the basis
to create the WSDL file using an Axis
“Java2WSDL” tool.
• Then use the WSDL as the basis to
create the requires Java files using an
Axis “WSDL2Java” tool
A1.11
Step 2 Generate files
Use the Axis tools to create four Java source files
from MyMath.jws with the composite command:
java -classpath $AXISCLASSPATH
\
org.apache.axis.wsdl.WSDL2Java \
http://localhost:8080/axis/MyMath.jws?wsdl
A1.12
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 in
localhost/axis/yourusername/MyMath_jws/
which is in
/home/yourusername/WebServices/
A1.13
MyMath.java -- Client code
MyMathService.java -- Service code
A1.14
MyMathServiceLocator.java -- Java class
used by client to find location of service.
MyMathSoapBindingStub.java -- Java class
that converts client service call to form to be
sent to service. – client stub.
A1.15
Other files
deploy.wsdd – WSDD file provided to
registry when service deployed.
undeploy.wsdd -- for undeploying service
A1.16
Files used by service
Service stub (skeleton):
MyMathSoapBindingSkeleton.java
MyMathSoapBindingImpl.java – used by
MyMathSoapBinding Skeleton.java
A1.17
Structure
deploy.wsdd WSDD
undeploy.wsdd
Registry (Locator)
MyMathServiceLocator.java
Client
Stub
Deploy
Request WSDL
WSDL
Stub Service
Method call/return
WSDL
MyMathClient.java
MyMathSoapBindingSkeleton.java
MyMathSoapBindingStub.java
MyMathService.java
MyMath.java
MyMath.wsdl
A1.18
Step 3 Compile new source files
Compile source files generated by step 2 with:
javac -classpath $AXISCLASSPATH \
localhost/axis/yourusername/MyMath_jws/*.java
A1.19
Step 4: Write Client Source
Below is client code for an earlier version of Axis (1.1).
Version 1.2 used in the assignment requires more code.
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));
}
}
A1.20
Step 5 Compile Client code
Compile the client source file with:
javac -classpath $AXISCLASSPATH:. MyMathClient.java
A1.21
Step 6 Execute Web Service program
java -classpath $AXISCLASSPATH MyMathClient 4
The square of 4 is 16
A1.22
Step 7 Extend the Web Service
Add functionality to the MyMath web service:
• Add a method that identifies whether a number is
even.
• Add a method that identifies whether a number is
prime.
Modify MyMath.jws file and repeat all previous
steps to test the extended web service.
A1.23