Web servisu izstrade

1
Web servisu izstrade
JAX-WS
2
Ievads

• JAX-WS Java API for XML Web Services
• JAX-WS ir fundamentala Web servisu izstrades
  tehnologija
• Java EE 5 un Java SE 6 sastavdala
• JAX-WS 2.0 aizvietoja JAX-RPC
• Pareja no RPC-style uz document-style web
  servisiem
• Reference Implementation by GlassFish

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Priekšvesture JAX-RPC

• JAX-RPC Java API for XML-based RPC
• Pirma specifikacijas versija (JAX-RPC 1.0) bija
  JSR-101 un ta bija izlaista 2002.gada junija
• Fundamentalais merkis - vienkaršot sazinašanas
  starp Java un ne-Java platformam
• Dod iespeju no Java programmas izsaukt Java Web
  servisu ar zinamu aprakstu (saskana ar servisa
  WSDL)

4
JAX-RPC modelis

• JAX-RPC modelim, ir divas puses
• Server-side programming model
• Allows to develop Web service endpoints as Java
  objects or Enterprise JavaBeans, which run on the
  J2EE platform
• Client-side programming model
• Allows to access a remote Web service as if it
  were a local object, using methods that represent
  SOAP operations

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Server-Side Programming

• Two server-side programming models for creating
  Java EE Web service endpoints
• POJO endpoints
• EJB3 Stateless
• Session Bean
• endpoints

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JAX-WS Annotations

• Annotations play a critical role in JAX-WS 2.0
• Annotations are used in mapping Java to WSDL and
  schema
• Annotations are used in runtime to control how
  the JAX-WS runtime processes and responds to web
  service invocations
• Annotations utilized by JAX-WS 2.0 are defined in
  separate JSRs
• JSR 181 Web Services Metadata for the JavaTM
  Platform
• JSR 222 JavaTM Architecture for XML Binding
  (JAXB) 2.0
• JSR 224 JavaTM API for XML Web Services (JAX-WS)
  2.0
• JSR 250 Common Annotations for the JavaTM
  Platform

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Web Service Implementation

• Write a POJO implementing the service
• Add _at_WebService annotation to it
• Optionally, inject a WebServiceContext
• WebServiceContext makes it possible for a web
  service endpoint implementation class to access
  message context and security information relative
  to a request
• Deploy the application
• Point your clients at the WSDL
• e.g. http//myserver/myapp/MyService?WSDL

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Example HelloWebService

• _at_WebService(name "HelloWebService")
• _at_SOAPBinding(
• style SOAPBinding.Style.DOCUMENT,
• use SOAPBinding.Use.LITERAL,
• parameterStyle
• SOAPBinding.ParameterStyle.WRAPPED)
• public class HelloWebService
• _at_WebMethod
• public String hello(_at_WebParam(name "name")
• String name)
• return "Welcome " name " !!!"

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More Annotations

• Web Services Metadata Annotations
• _at_WebService
• _at_WebMethod
• _at_OneWay
• _at_WebParam
• _at_WebResult
• JAX-WS Annotations
• _at_RequestWrapper
• _at_ResponseWrapper
• _at_WebEndpoint
• _at_WebFault
• _at_WebServiceClient
• _at_WebServiceRef

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Web Service Deployment

• To run Web service youll need to deploy it into
  web server with Java EE compliant web services
• Java service endpoint usually is packaged as a
  web application in a WAR file
• We will consider JBoss Application Server with
  JBoss Web Services (JBossWS)

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JBoss Web Services

• JBossWS is a JAX-WS compliant web service stack
  developed to be part of JBoss' Java EE 5 offering
• At deployment time JBossWS will create services
  endpoints from annotated classes and publish the
  WSDL
• At runtime SOAP requests are converted to JAVA
  invocations

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JBossWS deploy-time run-time
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Demo

• Ir sagatavots demo projekts
• http//java-eim.googlecode.com/svn/trunk/
• java-eim-demo-jbossws
• Pašlaik ir izveidoti divi vienkarši Web servisi
• HelloWebService
• CalculatorWebService
• Instrukcijas pagaidam faila README.txt

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JBossWS Console

• http//localhost8080/jbossws/

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Client-Side Programming

• JAX-WS client programming models
• Static ? Dynamic proxy client API
• Dynamic ? Dispatch client API
• Dynamic proxy client
• Invokes a Web service based on a Service Endpoint
  Interface (SEI) which must be provided
• Creating web service clients usually starts from
  the WSDL (WSDL first approach)
• Special tools are used to generate client classes

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Dispatch client API

• Low level JAX-WS API to work at the XML message
  level or without any generated artifacts
• Requires clients to construct messages or message
  payloads as XML
• Requires an intimate knowledge of the desired
  message or payload structure

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Client Side Generation (JBossWS)

• JBossWS provide a tool for client side generation
  from WSDL
• wsconsume
• From ltJBOSS_HOMEgt/bin execute
• wsconsume -k -p ltpackagegt ltpath_to_wsdlgt

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Generated Files

• HelloWebServiceService.java
• Service factory
• HelloWebService.java
• Service Endpoint Interface
• Hello.java
• Custom data type for request
• HelloResponse.java
• Custom data type for response
• ObjectFactory.java
• JAXB XML Registry
• package-info.java
• Holder for JAXB package annotations

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Client Code

• import xxx.generated.hello.HelloWebService
• import xxx.generated.hello.HelloWebServiceService
  
• public class HelloWebServiceClient
• public static void main(String args)
• HelloWebServiceService helloFactory
• new HelloWebServiceService()
• HelloWebService helloService
  helloFactory.getPort(HelloWebService.class)
• String response helloService.hello("WebService
  Client")

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Web Service Invocation

1. A Java program invokes a method on a stub (local
   object representing the remote service)
2. The stub invokes routines in the JAX-WS runtime
   system
3. The runtime system converts the remote method
   invocation into a SOAP message
4. The runtime system transmits the message as an
   HTTP request

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Server-Side Debugging (JBoss)

• Add or un-comment the following line in run.bat
• rem JPDA options. Uncomment and modify as
• rem appropriate to enable remote debugging.
• set JAVA_OPTS-Xdebug -Xrunjdwptransportdt_socke
  t,
• address8787,servery,suspendn JAVA_OPTS
• 2. Create new Remote Java Application debug
  configuration in Eclipse ? Run ? Open Debug
  Dialog

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Server-Side Debugging (JBoss)
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Server-Side Debugging (JBoss)

1. Start JBoss
2. Launch Debug configuration in Eclipse

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Server-Side Debugging (JBoss)

• Add breakpoint, e.g. to Web service code and run
  client
• Server will stop at breakpoint

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Server-Side Debugging (JBoss)
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Nobeigums

• Tas bija tikai iss ievads..!
• Web servisu temats ir daudz plašaks...

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References

• JAX-WS Annotations
• https//jax-ws.dev.java.net/jax-ws-ea3/docs/annot
  ations.html
• JBossWS Home
• http//labs.jboss.com/jbossws/
• JBossWS Wiki
• http//jbws.dyndns.org/mediawiki/index.php?title
  JBossWS

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References

• JAX-WS Reference Implementation by GlassFish
• https//jax-ws.dev.java.net/
• JAX-WS Specification (JSR 224) http//jcp.org/en/j
  sr/detail?id224
• Presentation about JAX-WS http//gceclub.sun.com.c
  n/java_one_online/2006/TS-1194/TS-1194.pdf