Developing Web Services. with Axis. Web Languages Course 2009 University of Trento

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1 Developing Web Services with Axis Web Languages Course 2009 University of Trento

2 Lab Objective Develop and Deploy Web Services (serverside)

3 Lab Outline WS Sum Up: WS-protocols Axis Functionalities WSDL2Java Tool Web Services Deployment JWS WSDD Web Services Development Skeleton Generation (WSDL2Java tools) WSDL Generation

4 Web Service Sum-up web service protocols

5 Web Services Protocols REST (Representational State Transfer): uses plain old HTTP to make method calls and you get XML back. XML-RPC: is a remote procedure call protocol which uses XML for marking up both requests and responses. SOAP (Simple Object Access Protocol): is a protocol specification for exchanging structured information in the implementation of Web Services in computer networks.

6 WS protocol stack

7 XML- messaging 1

8 XML- messaging 2

9 Big Web Service Is available over the Internet or private (intranet) networks Uses a standardized XML messaging system Is not tied to any one operating system or programming language Is self-describing via a common XML grammar (WSDL) Is discoverable via a simple find mechanism (UDDI)

10 WS architecture

11 Web Service Sum-up Axis functionalities

12 General Web Service Toolkit Functionality

13 Toolkit Functionality for Today Class

14 server WSDL2Java Tool Stub classes from a Java interface/class *: 1. *.java: New interface file with appropriate remote usages. 2. *Service.java: client side service interface. 3. *ServiceLocator.java: client side service implementation factory. 4. *SoapBindingStub.java: Client side stub. 5. (data types): Java files produced for non-standard types. 6. *SoapBindingImpl.java: default server implementation WS, modify manually to actual implementation. 7. *SoapBindingSkeleton.java: Server side skeleton. Deploy.wsdd / undeploy.wsdd: (Un-)deployment descriptors 23 March 2009 Gaia Trecarichi - Web Languages Course

15 Relationships Between Generated Files

16 WSDL2Java Generates 6 For each WSDL file Deployment descriptor called deploy.wsdd used by AdminClient to deploy the service implementation class referred to will either be the skeleton class (if skeleton generated) or the impl. class (if no skeleton generated) can change to refer to your own class Undeployment descriptor called undeploy.wsdd used by AdminClient to undeploy the service

17 Using WSDL2Java Command java org.apache.axis.wsdl.wsdl2java wsdl-uri Option highlights -Nnamespace=package : maps a namespace to a Java package -o dir : specifies output directory where generated files should be written -p pkg : overrides default package name for generated classes -s : generates service-side interfaces and classes required by a service implementation, including a skeleton class -t : generates JUnit test case for the web service -v : prints a message about each file that is generated

18 Web Services Deployment Simple Deployment (JWS) WSDD Deployment

19 Deploying Java Web Services (JWS) 1 Steps If not there already, copy axis directory in webapps directory of the Axis distribution to the deployment directory of a server that supports Java servlets For Tomcat, this is the webapps directory Copy any Java source file that implements a web service into this axis directory No special code is required All public, non-static methods are exposed

20 Deploying Java Web Services (JWS) 2 Change the file extension from.java to.jws To view the WSDL of a JWS web service, enter the following URL in a web browser JWSHandler, JWSProcessor RPCProvider classes do the job A file.class is created under the dir \webapps\axis\web-inf\jwsclasses 23 March 2009 Gaia Trecarichi - Web Languages Course

21 Java Web Services (JWS) Pros Simple to create Simple to deploy Simple to start with Cons No user defined binding of service name and implementation class No WSDL Hard to publish Hard to administrate No remote transparency

22 Customized Deployment 1 Benefits over JWS deployment deploy/undeploy multiple services deploy/undeploy handlers deploy classes with no source custom type mapping Server-side classes these are web service implementation classes and classes they use when using Axis webapp copy.class files to webapps/axis/web-inf/classes copy.jar files to webapps/axis/web-inf/lib

23 Customized Deployment 2 Web Service Deployment Descriptor (WSDD) Specifies components to be deployed and undeployed Specifies type mappings AdminClient uses WSDD typically called deploy.wsdd or undeploy.wsdd To deploy or undeploy components, pass it a WSDD file java org.apache.axis.client.adminclient filename.wsdd modifies server-config.wsdd in the axis webapp WEB-INF directory To list deployed components java org.apache.axis.client.adminclient list outputs server-config.wsdd which is used when the server is restarted to redeploy all previously deployed services 23 March 2009 Gaia Trecarichi - Web Languages Course

24 WSDD To Deploy Generated by WSDL2Java Example to deploy a service identifies the pivot handler to be used; Axis provides three: RPC, MSG and EJB; MSG is for message or document-centric calls as opposed to RPC-style calls <deployment xmlns=" xmlns:java=" <service name="carquote" provider="java:rpc"> <parameter name="classname" value="com.ociweb.auto.carquoteimpl"/> <parameter name="allowedmethods" value="*"/> </service> </deployment> makes all public, non-static methods of the class available; can be a whitespacedelimited list of method names don t need to have source for this class 23 March 2009 Gaia Trecarichi - Web Languages Course

25 WSDD To Undeploy Generated by WSDL2Java Example to undeploy a service <undeployment xmlns=" <service name="carquote"/> </undeployment> 23 March 2009 Gaia Trecarichi - Web Languages Course

26 Java Bean Registration with WSDD For Automatic Serialization Example for the Car class <deployment xmlns=" xmlns:java=" <service name="carquote" provider="java:rpc"> <parameter name="classname value="com.ociweb.cardealer.carquoteimpl"/> <parameter name="allowedmethods" value="getquote"/> </service> <beanmapping qname="ns:car" xmlns:ns="urn:carquote" languagespecifictype="java:com.ociweb.cardealer.car"/> </deployment> namespace beanmapping is needed if a Car object is passed to or returned from a web service operation 23 March 2009 Gaia Trecarichi - Web Languages Course

27 Custom Type Mapping 1 Steps write serializer class implements org.apache.axis.encoding.serializer write serializer factory class that returns serializer instances implements org.apache.axis.encoding.serializerfactory write deserializer class extends org.apache.axis.encoding.deserializerimpl write deserializer factory class that returns deserializer instances implements org.apache.axis.encoding.deserializerfactory

28 Custom Type Mapping 2 Register them using WSDD and the Admin client <typemapping xmlns:ns="urn:carquote" qname="ns:car" type="java:com.ociweb.cardealer.car" serializer="com.ociweb.cardealer.carserializerfactory" deserializer="com.ociweb.cardealer.cardeserializerfactory" encodingstyle=" </typemapping> add as child of deployment element 23 March 2009 Gaia Trecarichi - Web Languages Course

29 Web Services Development Server-side classes generation WSDL2Java tool WSDL Generation Exercises

30 Server-side classes Generation Steps Take a WSDL file, that is, the description of a service. Use WSDL2Java tool for generating WSDD files, Skeleton (optional) and Implementation class: java -cp %AXISCP% org.apache.axis.wsdl.wsdl2java AddFunction.wsdl o src s [-S true] Modify the *Impl.java file according to your implementation Compile the server-side classes (*PortType/*Impl/ *Skeleton.java). javac -d classes src\localhost\axis\addfunction_jws\*.java

31 WSDD Deployment Copy the generated classes under../axis/web-inf/classes Startup tomcat Run \apache-tomcat \bin\startup.bat Undeploy the service java -cp %AXISCP% org.apache.axis.client.adminclient src\localhost\axis\addfunction_jws\undeploy.wsdd Deploy the service java -cp %AXISCP% org.apache.axis.client.adminclient src\localhost\axis\addfunction_jws\deploy.wsdd [optional but adviced] Shutdown tomcat Run \apache-tomcat \bin\shutdown.bat [optional but adviced] Startup tomcat Run \apache-tomcat \bin\startup.bat

32 Exercise 1 Realize the steps described before, taking as a WSDL file AddFunction.wsdl You should see something like that Click on wsdl link Compare the browsed wsdl with the original Where is the difference?

33 Web Service Development There are three basic methods: 1. Instant Deployment (JWS) Generates a WSDL from an URL For simple services 2. WSDD Deployment (manual wsdd creation) Generates a WSDL from an URL 3. WSDD Deployment (automatic wsdd creation) Use java2wsdl to generate the WSDL from Java service implementation classes 23 March 2009 Gaia Trecarichi - Web Languages Course

34 Web Service Development Steps 1. Create the code for your service 2. Create the wsdd files (deploy.wsdd and undeploy.wsdd) 3. Compile the service code 4. Copy the classes under /axis/web-inf/classes 5. Deploy the service with AdminClient 6. [optional] Create the service stubs (with WSDL2Java tool) Note: [optional but advised] Use an Ant Task to automate the steps 3-6

35 Exercises Developing web services

36 Exercise 2 Steps Download the source code Open the project Lab7 Have a look to the files Calculator.java, deploy.wsdd, undeploy.wsdd, build.xml Change the properties (files build.properties) according to your settings Run the ant task deploy A service named Calculator should be created Check on the Axis page Run the ant task create-stubs see what happens Write a client to test the new deployed service

37 Exercise 3 Make a service that Given: a customer order Return: a string with info concerning the order Hints & Advices: the customer order is represented by a Java Bean class which contains, among the others, info like the customer name, the shipping address, a list of items to buy and respective quantities Create a new project (i.e., Order) Copy the files build.xml and *.properties from the project Lab7 Deploy the service with your own wsdd file Hints: remember to enclose in the wsdd file the type mapping using the beanmapping tag Generate the service stubs (for next exercise)

38 Exercise 4 Build a Client to test the Service of Exercise 7 1. Make a Client using DII Hints: add the following lines of code in the main of the Client class Qname qn = new QName( YourBeanNameSpace", YourBeanName" ); call.registertypemapping(yourbeanname.class, qn, new org.apache.axis.encoding.ser.beanserializerfactory(yourbeanname.class, qn), new org.apache.axis.encoding.ser.beandeserializerfactory(yourbeanname.class, qn)); 2. Make a Client using Service Stubs 23 March 2009 Gaia Trecarichi - Web Languages Course

39 Web Service Development There are three basic methods: 1. Instant Deployment (JWS) Generates a WSDL from an URL For simple services 2. WSDD Deployment (manual wsdd creation) Generates a WSDL from an URL 3. WSDD Deployment (automatic wsdd creation) Use java2wsdl to generate the WSDL from Java service implementation classes 23 March 2009 Gaia Trecarichi - Web Languages Course

40 Build.xml: axis-java2wsdl  <target name="create-wsdl" depends="do-jar" description="gen WSDL from java"> <mkdir dir="${wsdl}" /> <axis-java2wsdl classname="yourclassname" namespace=" location=" style="rpc" output="${j2w.wsdl}"> <classpath> <path path="${wsdl.classpath}" /> </classpath> </axis-java2wsdl> </target> 5/5/2009 Gaia Trecarichi - Web Languages Course 40

41 Web Service Development: use of Java2Wsdl tool 1 1. Starting from you service implementation, create a wsdl file Use ant task create-wsdl In the project.properties file: #for java2wsdl j2w.classname=myservice.myserviceimpl j2w.namespace= j2w.location= t.appname}/services/${service.name} j2w.style=rpc wsdl=wsdl j2w.wsdl=${wsdl}/${service.name}.wsdl wsdl.classpath=${build.service.local}

42 Web Service Development: use of Java2Wsdl tool 2 2. Given the wsdl just created, generate the stub classes Use ant task create-stubs (which make use of wsdl2java tool) Notice that you do this for two reasons: - to generate the deploy.wsdd and the undeploy.wsdd * - to generate the stub classes (client side) to be imported in my tester class * The option serverside="true must be enabled in order to obtain the.wsdd files

43 Web Service Development: use of Java2Wsdl tool 3 3. In the wsdd file generated, change the line <parameter name="classname" value= *SoapBindingImpl> into the line: <parameter name="classname" value= myservice.myserviceimpl> : Notice that when the wsdd is automatically generated, Axis puts "*SoapBindingImpl" because it takes the name from the skeleton class (which you don't use because you have already your service implementation). Actually, the class where the service is implemented is myservice.myserviceimpl, that's why you have to change it.

44 Web Service Development: use of Java2Wsdl tool 4 4. [optional, for cleaness purposes]: put the.wsdd files under the directory "deployment" of your project Notice that if you skip this step, you have to set the proper lines in the project.properties file to tell Axis where are the.wsdd files: #directory containing the deployment files deployment.wsdd=deployment/deploy.wsdd undeployment.wsdd=deployment/undeploy.wsdd

45 Web Service Development: use of Java2Wsdl tool 5 5. Deploy the service Use ant task deploy 6. Test the service with a Client Notice that you already have the stub jar (created in step 2)

46 Exercise 5 As in Exercise3, make a service that Given: a customer order Return: a string with info concerning the order Hints & Advices: Create a new project (i.e., Order1) Copy the files build.xml and *.properties from the project Lab7 Use Java2WSDL tool to create the wsdl file Hints: use target create-wsdl of build.xml Create *.wsdd files and modify deploy.wsdd properly Deploy the service Generate the service stubs and make a test client

47 Some Remarks Use Java Beans when you want to pass complex data types as input/output parameters for your own web services. Axis doesn t mind if you nest Java Beans as much as you want Don t try to pass ArrayList types. Use the Java arrays instead.

48 References Axis User Guide Provided in the course website Which style of WSDL should I use? s-whichwsdl/#listing7 W3C s Web Services Activity Home Page:

49 Troubleshooting

50 Ant Problems 1 Eclipse seems to recognize an Ant file (i.e., build.xml) but cannot actually run its targets It may be a problem of Eclipse version, ant version, how Eclipse was installed. Actions If you have Ubuntu, avoid the Eclipse packages provided by Ubuntu. Install Eclipse by downloading it from the official website Run the ant file from the command line Tell eclipse to use an external ant installation and see what happens (last option so far)

51 Ant Problems 2 It doesn t calculate the correct path according to the given settings Example: you fixed. as a basedir property in your build.xml file and some files (i.e, the wsdl file), indicated together with a relative path (i.e, wsdl) in a.properties file (i.e, stub.properties), are not accessible. It may be a problem of Ant version (?) Action put the absolute path for the file in question (i.e., wsdl file) file:///c://blabla//file.wsdl

52 WSDL Problems Make sure you save the WSDL file in the correct way DON T COPY AND PAST THE CONTENT OF THE WEB PAGE SAVE THE FILE AS AN XML FILE AND CHANGE THE EXTENSION TO WSDL

53 Axis Problems Make sure the 14 axis libraries (*.jar) are placed under %TOMCAT_HOME%/webapps/axis/WEB-INF/lib List of the libraries: activation.jar t axis-ant.jar axis.jar commons-discovery-0.2.jar commons-logging jar jaxp-1.3.jar jaxrpc.jar log4j jar mail.jar saaj.jar servlet-api.jar wsdl4j jar xml-apis.jar, tool.jar

54 WSDD Deployment in Linux Type the command env to display your Unix environment variables If not there, set the environmental variable AXISLIB with the command export export AXISLIB= /webapps/axis/web-inf/lib Type the following command to deploy a service java -cp $AXISLIB/activation.jar:$AXISLIB/axis.jar:$AXISLIB/commons-discovery- 0.2.jar:$AXISLIB/commons-logging jar:$AXISLIB/jaxrpc.jar:$AXISLIB/log4j jar:$AXISLIB/mail.jar:$AXISLIB/saaj.jar:$AXISLIB/wsdl4j jar:$AXISLIB/xml-apis.jar:$AXISLIB/axis-ant.jar org.apache.axis.client.adminclient -h yourhostname -p tomcatport /fulldeploypath/deploy.wsdd Usually Usually March 2009 Gaia Trecarichi - Web Languages Course

Invoking Web Services. with Axis. Web Languages Course 2009 University of Trento

Invoking Web Services. with Axis. Web Languages Course 2009 University of Trento Invoking Web Services with Axis Web Languages Course 2009 University of Trento Lab Objective Refresh the Axis Functionalities Invoke Web Services (client-side) 3/16/2009 Gaia Trecarichi - Web Languages