SERVICE TECHNOLOGIES 1

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1 SERVICE TECHNOLOGIES 1 Exercises 2 02/04/2014 Valerio Panzica La Manna valerio.panzicalamanna@polimi.it

2 Lesson learned With Jax-Ws you can easily: create Java Web Service. deploy your Service with Endpoint. create Java Service Client (wsimport). Everything included in Java Standard Edition 7 but We want something that automatize the entire process (no more command line). We need a powerful container: managing multiple requests. with extra features (RDBMS ) How wsimport really works

3 Outline We want something that automatize the entire process (no more command line). Ant We need a powerful container: managing multiple requests. with extra feautures (RDBMS ) How wsimport really works Creating and Deploying a Java Web Service in GlassFish JAXB

4 Ant Apache Ant is a Java library and command-line tool used: to build Java Applications. in many open-source projects. Also used to automatize: configuration packaging testing deploy documentation much more Entirely written in Java and extensible.

5 Using Apache Ant Based on the concept of task: a wide variety of built-in tasks are available. you can build your own task. Tasks can be aggregated into target tasks belonging to the same target cooperate to reach a desired state during the building process. A target may depend on other targets Each Ant project is described by a build.xml buildfile: with project as the root node. containing different target nodes. there is always a default target.

6 Project Attribute name default basedir Description the name of the project. the default target to use when no target is supplied. the base directory from which all path calculations are done. If neither the attribute nor the property have been set, the parent directory of the buildfile will be used. <project name="firstproject" default="helloworld" basedir="."> <target name="helloworld"> <echo>hello World!</echo> </target> </project>

7 Target A target is a set of tasks you want to be executed. You can select which target to execute. Target may depend on other targets. <target name="a"/> <target name="b" depends="a"/> <target name="c" depends="b"/> <target name="d" depends="c,b,a"/> Suppose we want to execute target D what is the call ordering? A à B à C à D

8 Properties An important way to customize a build process. Provide shortcuts for strings that are used repeatedly inside a build file. called by ${propertyname}! A property can be defined: inside the project node or in an external file (using the standard XML import) <property name= myname value= myvalue />! or referring to environment variable: <property environment= env />! <property name= java.home value= ${env.java_home} />! built-in properties: basedir, project.name, ecc

9 Example <project name="myproject" default="dist" basedir=".">!! <! global properties -->! <property name="src" value="${basedir}/src"/>! <property name="build" value="${basedir}/build"/>! <property name="dist" value="${basedir}/dist"/>!! <target name="init">! <! Creating the destination directory for compilation -->! <mkdir dir="${build}"/>! </target>!! <target name="compile" depends="init">! <! Compiling Java code in ${src} and put in ${build} -->! <javac srcdir="${src}" destdir="${build}"/>! </target>!! <target name="dist" depends="compile">! <! Creating deploy directory -->! <mkdir dir="${dist}"/>! ! <jar jarfile="${ant.project.name}.jar basedir="${build}"/>! </target>! </project>

10 Conditional targets Executing based on properties: <target name="module-a" if="property-a-present"/>! <target name="module-a" unless="property-a-present"/> Executing a target if property-a-present is set (also to false). Executing a target only if property-a-present is not set. To check multiple conditions you need another target: <target name="mytarget" depends="mytarget.check" if="mytarget.run">! <echo>files foo.txt and bar.txt are present.</echo>! </target>! <target name="mytarget.check">! <condition property="mytarget.run">! <and>! <available file="foo.txt"/>! <available file="bar.txt"/>! </and>! </condition>! </target>

11 Path-like structures Can be specified using path or classpath <classpath>! <pathelement path="${classpath}"/>! <pathelement location="lib/helper.jar"/>! </classpath> path attribute is intended to be used with predefined paths path accepts colon (Unix,Linux, Mac) or semi-colon (Windows) separated lists of locations. location attribute specifies a single file or directory. Also Resource Collectors can be used: fileset dirset etc

12 Resource Collectors <classpath>!! <pathelement path="${classpath}"/>!! <fileset dir="lib">! <include name= *.jar"/>! </fileset>!! <pathelement location="classes"/>!! <dirset dir="${build.dir}">! <include name="apps/**/classes"/>! <exclude name="apps/**/*test*"/>! </dirset>!! </classpath> all elements in ${classpath} all jar files in lib directory directory named classes all directories named classes under apps except the ones having the word Test in their name

13 Path It is used to define path-like structures that are external to a target. the id must be unique. refid can be used to retrieve it. <path id="base.path">! <pathelement path="${classpath}"/>! <fileset dir="lib">! <include name="*.jar"/>! </fileset>! <pathelement location="classes"/>! </path>!! <target... >! <javac...>! <classpath refid="base.path"/>! </javac>! </target>! </project>

14 External Tasks ANT supports the plugin of new tasks: you need the jar implementing the task the new task must be defined in the buildfile: <taskdef name="taskname" classname="implementationclass"/>

15 Creating new tasks 1. Creating a class that extends org.apache.toos.ant.task! It allows to access to built-in properties 2. For each attribute providing a setter method. 3. Providing a method public void execute() with the code implementing the task package com.mydomain;! import org.apache.tools.ant.buildexception;! import org.apache.tools.ant.task;!! public class MyVeryOwnTask extends Task {! private String msg;! // The method executing the task! public void execute() throws BuildException {! System.out.println(msg);! }! // The setter for the "message" attribute! public void setmessage(string msg) {! this.msg = msg;! }! }

16 GLASSFISH

17 GlassFish An open source application server. Provides a fully-featured implementation of Java EE 7: JAX-WS JAX-RS JAXB EJB Web Container: deploys servlets and web services. Message-oriented middleware: supporting JMS (Java Message Service). RDBMS (Relational Database Management System) much more

18 JAX-WS: Apt task Runs the annotation processor tool (apt) Optionally compiles the original code. <apt destdir="${build.classes.home}" sourcedestdir="${basedir}/src" sourcepath="${basedir}/src"> <classpath refid="jaxws.classpath"/> <source dir="${basedir}/src"/> </apt>

19 JAX-WS: wsimport task generates JAX-WS portable artifacts: SEI Service JAXB generated value types <taskdef name="wsimport" classname="com.sun.tools.ws.ant.wsimport"> <classpath path="jaxws.classpath"/> </taskdef> <wsimport destdir="" debug="true" wsdl="addnumbers.wsdl" binding="custom.xml"/>

20 .war files Web Application archive file. Standard structure to respect: AppName WEB-INF web.xml sun-jaxws.xml web deployment descriptor jax-ws deployment descriptor classes SEI service implementation META-INF

21 jax-ws.xml Service Deployment descriptor: specifies where to find the concrete service implementation when a service is invoked. name: name of the endpoint implementation: where to find the SIB url-pattern: must be equal to the one specified in web.xml <?xml version="1.0" encoding="utf-8"?> <endpoints xmlns=" version="2.0"> <endpoint name="myhello" implementation="hello.helloimpl" url-pattern="/hello"/>! </endpoints>

22 web.xml Web Application deployment descriptor?xml version="1.0" encoding="utf-8"?> <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" " java.sun.com/j2ee/dtds/web-app_2_3.dtd"> <web-app> <listener> <listener-class>com.sun.xml.ws.transport.http.servlet.jaxrpccontextlistener</listener-class> </listener> <servlet> <servlet-name>hello</servlet-name> <servlet-class>com.sun.xml.ws.transport.http.servlet.jaxrpcservlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>hello</servlet-name> <url-pattern>/hello</url-pattern> </servlet-mapping> <session-config> <session-timeout>60</session-timeout> </session-config> </web-app>

23 Example: Calculator Eclipse Java EE Perspective. Service CalculatorWS Implementing the Service. Compiling and deploying the service using Ant. CalculatorClient: generating the needed artifacts with Ant and wsimport. Implementing the client.

24 JAXB Java Architecture for XML Binding. Provides a fast and convenient way to bind between XML schemas and Java representations. Used to: unmarshalling XML instance document into Java content trees marshalling Java content trees into XML instance documents. generate XML schemas from Java objects.

Generating content tree of data objects instantiated from the generated

25 JAXB Binding Process JAXB binding compiler generates JAXB classes given as input an XML schema Compiling classes. Unmarshalling. Generating content tree of data objects instantiated from the generated JAXB classes. Validate both source XML documents and processed content. Process content. Marshalling.

26 Representing XML Content Grouping the generated classes in packages. A package comprise: A Java class name is derived from the element name. An ObjectFactory class used to return instances of a bound Java class. Schema 2 Java xsd:string à java.lang.string xsd:int à int xsd:datetime à javax.xml.datatype.xmlgregoriancalendar xsd:anysimpletype à java.lang.object

27 Java 2 Schema XML schema that is generated from POJO with JAXB target namespace XML for a specifies the root mapping of attributes and package to Xml Schema mapping of a class to a schema mapping a field/property to an XML mapping a field/property to an XML attribute

28 Examples Unmarshal Read how to unmarshal an XML document into a Java content tree and access the data contained within it. Modify Marshal how to modify a Java content tree. Unmarshal Validate how to enable validation during unmarshalling. J2s-xmlAttribute how to use annotation to define a property or field to be treated as an XML attribute.

29 po.xsd <xsd:element name="purchaseorder" type="purchaseordertype"/> <xsd:element name="comment" type="xsd:string"/> <xsd:complextype name="purchaseordertype"> <xsd:sequence> <xsd:element name="shipto" type="usaddress"/> <xsd:element name="billto" type="usaddress"/> <xsd:element ref="comment" minoccurs="0"/> <xsd:element name="items" type="items"/> </xsd:sequence> <xsd:attribute name="orderdate" type="xsd:date"/> </xsd:complextype> <xsd:complextype name="usaddress"> <xsd:sequence> <xsd:element name="name" type="xsd:string"/> <xsd:element name="street" type="xsd:string"/> <xsd:element name="city" type="xsd:string"/> <xsd:element name="state" type="xsd:string"/> <xsd:element name="zip" type="xsd:decimal"/> </xsd:sequence> <xsd:attribute name="country" type="xsd:nmtoken" fixed="us"/> </xsd:complextype>

31 po.xml <?xml version="1.0"?> <purchaseorder orderdate=" "> <shipto country="us"> <name>alice Smith</name> <street>123 Maple Street</street> <city>cambridge</city> <state>ma</state> <zip>12345</zip> </shipto> <billto country="us"> <name>robert Smith</name> <street>8 Oak Avenue</street> <city>cambridge</city> <state>ma</state> <zip>12345</zip> </billto> <items> <item partnum="242-gz" > <productname>godzilla and Mothra: Battle for Earth</productName> <quantity>3</quantity> <USPrice>27.95</USPrice> </item> </items> </purchaseorder>

32 xjc Xjc binding compiler: XMLà Java classes <taskdef name="xjc" classname="com.sun.tools.xjc.xjctask"> <classpath> <fileset dir="${jaxws.lib}" includes="*.jar" /> </classpath> </taskdef> <target name="runxjc" description="compile schema"> <echo message="compiling the schema..." /> <xjc destdir="${src.dir}" package="primer.po"> <schema dir="${basedir}" includes="po.xsd" /> <produces dir="${src.dir}/primer/po" includes="**/*.java"/> </xjc> </target>

33 Generated Classes PurchaseOrderType

34 Generated Classes PurchaseOrderType USAddress.java

35 Generated Classes PurchaseOrderType USAddress.java Items.java

36 Generated Classes PurchaseOrderType USAddress.java Items.java ObjectFactory.java

37 Modify Marshal: Main.java try { // creating a JAXBContext to manage the package JAXBContext jc = JAXBContext.newInstance("primer.po"); // creating Unmarshaller Unmarshaller u = jc.createunmarshaller(); // unmarshalling JAXBElement poe = (JAXBElement) u.unmarshal( new FileInputStream("po.xml")); PurchaseOrderType po = (PurchaseOrderType) poe.getvalue(); // changing the Address USAddress address = po.getbillto(); address.setstreet("242 Main Street"); address.setcity("beverly Hills"); address.setstate("ca"); address.setzip(new BigDecimal("90210")); // create a Marshaller and marshalling Marshaller m = jc.createmarshaller(); m.setproperty(marshaller.jaxb_formatted_output, Boolean.TRUE); m.marshal(poe, System.out); } catch (JAXBException je) { je.printstacktrace(); } catch (IOException ioe) { ioe.printstacktrace(); }

38 Validation Verifying if an XML document meets all the constraints expressed in the schema

39 Back to CalculatorClient

40 Java 2 Schema : SchemaGen <taskdef name="schemagen" classname="com.sun.tools.jxc.schemagentask"> <classpath> <fileset dir="${jaxws.lib}" includes="*.jar" /> </classpath> </taskdef> <target name="runschemagen" description="compile schema"> <echo message="generating the schema..." /> <schemagen destdir="${basedir}/schemas"> <classpath refid="jaxws.classpath"/> <src path = "${src.dir}"/> </schemagen> </target> <schemagen srcdir="src" destdir="build/schemas"> <schema namespace=" file="myschema-common.xsd" /> <schema namespace=" file="myschema-onion.xsd" /> </schemagen>

41 J2s-XmlAttribute annotation maps a field or JavaBean property to an XML attribute. The following rules are imposed: A static final field is mapped to a XML fixed attribute. When the field or property is a collection type, the items of the collection type must map to a schema simple type. When the field or property is other than a collection type, the type must map to a schema simple type. You can set on the field the getter the setter You can specify optional element name namespace required

42 HANDLERS

43 Handlers in JAX-WS Message interceptors plugged into the JAX-WS runtime. Both client-side and server-side. Used to do additional processing of inbound/outbound messages. Client/Provider Authentication. Client/Provider Performance Monitor. Envelope/HTTP/Payload logging.

44 Protocol and Logical Handlers Handler<C extends MessageContext> boolean handlemessage (C context) boolean handlefault (C context) void close (MessageContext context) LogicalHandler<C extends LogicalMessageContext> SOAPHandler<C extends SOAPMessageContext> Set<QName> getheaders() Protocol Handlers: may access or change the protocol specific aspects of the message. Only SOAPHandler actually available. Logical Handlers: protocol-agnostic. act only on the payload of the message.

45 Message Context A bag of properties shared by: client, client run-time, client-side handlers. provider, provider run-time, provider-side handlers. LogicalMessageContext LogicalMessage getmessage() Map <String, Object> MessageContext Enum Scope SOAPMessageContext Object[] getheader(...) Set<String> getroles() SOAPMessage getmessage() void setmessage(soapmessage) Examples of properties: MESSAGE_OUTBOUND_PROPERTY (Boolean): specifies message direction. INBOUND_MESSAGE_ATTACHMENTS (java.util.maps): access to the inbound message attachments. OUTBOUND_MESSAGE_ATTACHMENTS (java.util.maps): access to the outbound message attachments.

46 Handlers in practice Handlers are programmer-written class that contains callbacks. Methods invoked by the JAX-WS runtime so that an application has access to: the underlying SOAP for SOAPHandlers the payload for Logical Handlers. A Handler can be injected into the handler framework in two steps: Create a Handler class (implemeting the *Handler interface) with handlemessage(), handlefault(), close(). getheaders() (only for SOAPHandler). Place a handler within a handler chain. Through configuration file or code.

47 The RabbitCounter Example The RabbitCounter service has one operation (countrabbits) that computes the Fibonacci numbers. a SOAP fault is thrown if the argument is a negative integer. The service, its clients, and any intermediaries are expected to process SOAP headers: client injects a header block. intermediaries and the service validate the information in the header block. generating a SOAP Fault if necessary. Two ways to throw SOAP faults: extend the Exception class and throw the exception throw a fault from a handler.

48 The RabbitCounter Example Injecting a Header Block into a SOAP Header. FibClient generates a request against the RabbitCounter. The client-side JWS libraries create a SOAP message that serves as the request. The UUIDHandler callbacks are invoked. The handlemessage callback has access to the whole SOAP message and injects a UUID (Universally Unique Identifier) value into the header.

49 handler-chain.xml

50 Order of execution in handler chain Typically the top-to-bottom sequence of the handlers in the configuration file determines the order of execution. With some exceptions: For outbound messages handlemessage and handlefault in LogicalHandler execute before their counterparts in SOAPHandler. For inbound messages handlemessage and handlefault in SOAPHandler execute before their counterparts in LogicalHandler.

51 Example Handler-chain: SH1 LH1 SH2 SH3 LH2 Inbound messages: SH1 SH2 SH3 LH1 LH2 Outbound messages: LH1 LH2 SH1 SH2 SH3

52 Configuring the Client-Side Handler With a configuration file: In the ws-import generated class FibC.RabbitCounterService simply add the = "handler-chain.xml") Or you can add the handler programmatically: SEE FibClientHR

53 SOAP Fault In handler.fib.rabbitcounter a customized exception that countrabbits throws if it is invoked with a negative integer as argument. SOAP Message:

54 Adding a Logical Handler to the Client To avoid the fault let s add to the client the LogicalHandler ArgHandler that: intercepts the outgoing requests. check the argument to countrabbits change the argument if it is negative. It uses a JAXBContext to extract the payload ( in this case the body of the outgoing SOAP message). Get Check - Change - Set the arg0 (the argument of CountRabbits). Add ArgHandler in the handler-chain

55 Adding a Service-Side SOAP Handler To complete the example we need a service-side SOAP handler to process the header block and throw a fault if needed. see UUIDValidator

56 OVERVIEW ABOUT WS-*

57 Ensuring Interoperability Sun and Microsft work together to ensure interoperability between java web services and Windows Communication Foundation. Result: WSIT (Web Service Interoperability Technology). Support for some of WS* specification: WS-Policy Ws-Security Ws-ReliableMessaging Ws-Transaction WSIT is the default implementation for these standards in Metro and Glassfish.

58 Example ReliableHelloWorld in NetBeans Showing NetBeans support for implementing WebServices

59 Apache CXF Another Java Implementation of Web Service Stack Alternative to Metro. Used in conjunction with Spring. Can be also independently deployed. Implements JAX-WS Higher support for WS*

Constraints, Meta UML and XML. Object Constraint Language

Constraints, Meta UML and XML. Object Constraint Language Constraints, Meta UML and XML G. Falquet, L. Nerima Object Constraint Language Text language to construct expressions for guards conditions pre/post conditions assertions actions Based on navigation expressions,