SERVICE TECHNOLOGIES 1

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1 SERVICE TECHNOLOGIES 1 Exercises 1 19/03/2014 Valerio Panzica La Manna valerio.panzicalamanna@polimi.it

2 Outline Web Services: What? Why? Java Web Services: JAX-WS Your First Web Service: TimeServer Testing the Web Service Coding the client A closer look to WSDL A useful tool: wsimport Example 2: A Client from real web service Example 3: Teams Richer data types

3 What is a Web Service? A distributed application typically delivered over the Web. Its components can be deployed, executed, and consumed on different devices. Web Services can be divided into two groups: SOAP-based. REST-Style. Key Feature: Interoperability Modular design: new services may be generated by integrating existing services. Language transparency: C/C++, PHP, C#, JavaScript, Ruby, Perl, Python, Java can be used to implement and consume web services. Open Infrastructure: standard and vendor independent protocols

4 JAVA WEB SERVICES

5 JAX-WS Java API for XML-Web Services The reference framework for Java Web Services Bundled into the Metro Web Services Stack Part of the Glassfish Application Server but Also available in the core Java Standard Edition 7.

6 JAX-WS Web Services as POJOs (Plain Old Java Objects) with Marks a Java class as the implementation of the WS Marks a Java interface as the interface implementation of the WS name -> wsdl:porttype servicename -> wsdl:service endpointinterface -> specifies the SEI Marks a method as the WS operation operationname -> Customizes the mapping of method params / return value to WSDL.

@WebService @WebService(targetNamespace = "http://duke.

7 = " name="addnumbers") public interface AddNumbersIF extends Remote public int number1,

@WebMethod @WebService(targetNamespace = "http://duke.

8 = " name="addnumbers") public interface AddNumbersIF extends Remote public int number1,

@WebParam @WebService(targetNamespace = "http://duke.

9 = " name="addnumbers") public interface AddNumbersIF extends Remote public int number1,

10 WS Programming Defining the SEI (Service Endpoint Interface) Marked Declaring the methods which are the web service operations. Marked Implementing the SIB (Service Implementation Bean) Defining the methods declared in the SEI. Publishing the WS: With core Java 7 With web-container (Tomcat) With Application Server (Glassfish) Let s see a first example

11 Exercise 1: Implement TimeServer Defining the SEI (Service Endpoint Interface) Implementing the SIB (Service Implementation Bean) Simple Deployment

12 Time Server TimeServer is the SEI TimeServerImpl is the SIB A Java Application to publish the WS (TimeServerPublisher) Testing the WS: With a Browser With SOAPUI 2 Clients: In Ruby In Java

13 Key Features of the example Web Service with two operations: Returned values with simple types. No parameters. Stateless. MEP (Message Exchange Pattern): request/response. Needed Infrastructure: Message Transport Neutrality. Service contract: WSDL Information about WS operations, args, return values. Service Endpoint (typically the service URL) Type System (XML Schema)

14 WSDL Structure types (optional) provides data type definition (typically under XML Schema). message defines the messages that implement the service. Constructed from data types defined in types. The order of the message defines the MEP. porttype presents the service as named operation. Each operation as one or more messages. Named after methods annotated binding specifies the implementation details: Transport protocol, the style and use (data format used in the SOAP messages). service specifies the service endpoints List of port (associating a porttype with a Binding).

15 WSDL Bindings style document document rpc rpc use literal encoded literal encoded The use attribute defines how the data types are encoded/ decoded. The encoded use does not comply with the WS-I guidelines. What are the differences between rpc and document? Let s modify our example

16 TimeServer with document style Three simple steps: Comment = Style.RPC) the document style is the default Compiling the source Run the TimeServerPublisher

17 Tradeoffs Between binding styles RPC The automatically gen WSDL is simpler (no types section) Do not carry any type encoding information (better throughput) The service cannot use arbitrarily rich data No XSD to validate of SOAP message document More complex. WS-I suggested style. A service can use an arbitrarily rich data types. The body of the SOAP message can be validated against the XSD in the types

18 TimeServer Client with wsimport Publishing the service ( and the associated wsdl ) In the src directory: wsimport -keep -p eser1.tsclient Easily create the tsclientfromwsdl Let s see how

19 Exercise 2: Euro Cup 2012 Requirements: Implementing a Java Application which prints to the console: All the city names where world cup games are played All the world players of all qualified teams All the strikers of the Italian Team The data source is provided as a web-service. You can find the WSDL at:

20 EuroCup 2012 Look at the WSDL through a browser. Use wsimport (in the src directory): wsimport -keep -p eser1.worldcupclient Implementing the EuroCupClient using the code generated by wsimport

21 Exercise 3: Richer Data Types 1. Implementing the Teams class and utility classes. 2. Compiling the source files. 3. The wsgen utility needed to generate the WSDL. (Not necessary in Java 7 with JAX-WS RI 2.1.4) In the bin directory: wsgen cp. eser1.team.teams 1. Publishing the service. 2. In the src directory invoke the wsimport utility: wsimport -p eser1.teamsc -keep 3. Coding the Client based on artifacts generated by wsimport.

22 Reference Book Martin Kalin Java Web Services: Up and Running, 2nd Edition O Reilly

JAX-WS 3/14/12 JAX-WS

JAX-WS 3/14/12 JAX-WS JAX-WS Asst. Prof. Dr. Kanda Runapongsa Saikaew Department of Computer Engineering Khon Kaen University http://gear.kku.ac.th/~krunapon/xmlws 1 Agenda q What is JAX-WS? q Quick overview of JAX-WS q Differences