Automated Tools for Web Services JAVA Version

1
Automated Tools for Web Services (JAVA Version)

• IWSJ Fall 2006, Lecture 10
• Adam Poswolsky
• 14 November 2006

2
Why Tools?

• Why not do everything by hand?
• Not masochistic.
• Why JAVA
• Tools also available for C, C, etc.

3
Quick Recap of Buzzwords

• SOAP
• XML-based communication protocol
• We are using on top of HTTP
• Not following REST architecture principal.
• WSDL
• Web Service Description Language
• Contract of Services provided.
• UDDI
• Service Registry
• Return WSDL documents for Services.

4
Web Services Platform
UDDI Registry
Find
Register
WSDL
Client
Server
SOAP
5
Apache Axis

• Axis is a SOAP engine
• Axis stands for Apache EXtensible Interaction
  System
• Facilitate creation of clients and servers using
  SOAP message framework.
• Extensive support for WSDL.
• Automatically create skeleton from WSDL.
• Or create WSDL based on JAVA code.
• And More!
• See Axis User guide
• http//ws.apache.org/axis/java/user-guide.html

6
Stylus Studio

• One of many possible frontends.
• Nice GUI utilities for
• XML Editing
• Create Schemas, Stylesheets, etc.
• Webservices
• But it needs underlying SOAP tools.
• You still need Apache Axis!
• http//www.stylusstudio.com

7
What will we do today? (1/2)

• Install Axis (if not on lab machines).
• Use tools to create a simple web service.
• Create Server
• Create WSDL
• Create Stub for Client
• Create Skeleton for Server
• Should we have created the WSDL first?
• We will need to plug web service into Tomcat.

8
What will we do today? (2/2)

• Service discovery and registration using UDDI
• UDDI4j is a Java class library providing an API
  to interact with a registry.
• Stylus Studio has a nice GUI interface to UDDI.

9
Simple Client (DKK to USD)
Execution C\axis\adamgtjava DKKtoUSD You should
give me ???DKK for just one USD.

• import org.apache.axis.client.
• import javax.xml.namespace.QName
• public class DKKtoUSD
• public static void main(String args)
• try
• Service service new Service()
• Call call (Call) service.createCall()
• call.setTargetEndpointAddress (new
  java.net.URL
• 
  ("http//localhost8080/axis/Exchange.jws"))
• call.setOperationName (new
  QName("http//DefaultNamespage",
• 
  "convert"))
• Float ret (Float) call.invoke (new
  Object"DKK", "USD")
• System.out.println("You should give me "
  ret
• "DKK for just one
  USD.")
• catch (Exception e) System.out.println(e.t
  oString())

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Simple Example Details (1/2)

• call.setOperationName (new QName("http//DefaultNa
  mespage",
• 
  "convert"))
• Namespace is used to distinguish between
  different convert functions.
• It should be globally unique!
• Does not need to be real
• i.e. you may not be able to access it via web
  browser.
• Could have used urnposwolsky-giveMeMoney

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Simple Example Details (2/2)

• IDEAL REQUEST
• ltSOAP-ENVEnvelope     ltSOAP-ENVBodygt        ltn
  s1convert xmlnsns1"http//DefaultNamespace"gt  
            ltfromSymbol xsitype"xsdstring"gtDKKlt/f
  romSymbolgt            lttoSymbol
  xsitype"xsdstring"gtUSDlt/toSymbolgt        lt/ns1
  convertgt    lt/SOAP-ENVBodygtlt/SOAP-ENVEnvelope
  gt

IDEAL RESPONSE ltsoapenvEnvelope
gtltsoapenvBodygtltns1convertResponse
soapenvencodingStyle"http//schemas.xmlsoap.org/
soap/encoding/" xmlnsns1"http//DefaultNamespace
"gtltconvertReturn xsitype"xsdfloat"gt?????lt/conv
ertReturngtlt/ns1convertResponsegtlt/soapenvBodygtlt
/soapenvEnvelopegt
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Monitoring Connections (TCPMon)

• Axis includes a tool called TCPMon
• Inspect SOAP messages to and from services.
• Resend messages
• Change messages
• .
• Execution
• java org.apache.axis.utils.tcpmon
• Alternatives
• Axis also has a SOAP monitor service which is
  disabled by default (for security concerns).

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java org.apache.axis.utils.tcpmon

• Choose some Listen Port
• E.g. 9999
• Change client to connect to Listen port instead
  of Tomcat Port (8080)

14
Easy Deployment of Web Services

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Easiest Possible Deployment

• For extremely simple Java programs,
• i.e. public class Calculator public int add(int
  i1, int i2) return i1 i2
• Just copy source (Calculator.java) to
  lttomcat-rootgtaxis/Calculator.jws
• Access service by
• http//localhost8080/axis/Calculator.jws
• Get automatic generated WSDL at
• http//localhost8080/axis/Calculator.jws?wsdl

16
Difficult (but more thorough) version of
Deployment

17
Isnt Easy enough?

• Limitations
• Cannot use packages.
• Must have access to the source.
• And it is compiled at run-time.
• No customization,
• But the axis team is working on allowing you to
  embed this metadata into your source-code.

18
Axis Web Service Deployment Descriptor (WSDD)

• WSDD describes what to make available to Axis
  engine.
• ltdeployment xmlns"http//xml.apache.org/axis/wsdd
  /"
• xmlnsjava"http//xml.apache.org/axis/wsdd/pr
  oviders/java"gt
• ltservice name"AdamCalcService"
  provider"javaRPC"gt
• ltparameter name"className"
  valueAdamCalcServiceClass/gt
• ltparameter name"allowedMethods" value""/gt
• lt/servicegt
• lt/deploymentgt
• Saved as deploy.wsdd

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Deployment

• Copy AdamCalcServiceClass.class to
  lttomcatgt\webapps\axis\WEB-INF\classes
• Run java org.apache.axis.client.AdminClient
  deploy.wsdd
• Now I can access at
• http//localhost8080/axis/services/AdamCalcServic
  e

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Advanced WSDD Features (1/2)

• When should Axis make new objects of the
  aforementioned class.
• They call this scoping
• Request scope
• Create a new object for every request (default).
• Application scope
• Singleton object for all requests.
• Session scope
• New object for each session-enabled client.

21
Advanced WSDD Features (2/2)

• Different Service Styles
• RPC (from our example) uses SOAP RPC conventions
  and SOAP encoding.
• Document and Wrapped do not use SOAP encoding for
  data (just specify XML Schema) but binds JAVA
  representations to the XML.
• In most cases you won't need to worry about
  document or wrapped services
• Message will give access to raw XML.
• You have to turn it manually into JAVA object.
• But you can verify with an XML Schema.

22
Java types to SOAP/XML types
Axis will only send objects for which there is a
registered Axis serializer. Axis includes the
ability to serialize/deserialize, without writing
any code, arbitrary Java classes which follow the
standard JavaBean pattern of get/set accessors.
All you need to do is tell Axis which Java
classes map to which XML Schema types.
Exceptions become SOAP faults.
23
Advanced Calculator Server
..gtjava AdamCalcServiceClass 128 to binary is
10000000 100 to decimal is 4

• public class AdamCalcServiceClass
• public static int binary2Int(String numBinary)
• int length numBinary.length()
• int least_sig_bit
• if (length 0) return 0
• if (numBinary.charAt(length-1) '1')
  least_sig_bit1
• else
  least_sig_bit0
• String restNum numBinary.substring(0,
  length-1)
• return least_sig_bit (2
  binary2Int(restNum))
• public static String int2Binary(int inputNum)
• int least_sig_bit inputNum 2
• int quotient inputNum / 2
• if (quotient0) return (Integer.toString(lea
  st_sig_bit))
• return (int2Binary(quotient)
  least_sig_bit)

24
Axis WSDL Support

• When you deploy a service, you can retrieve WSDL
  by appending ?WSDL to end of URL.
• Sample with AdamCalcService
• WSDL2Java tool
• Build java stubs/skeletons for services with WSDL
  descriptions.
• Business Contract approach would be to start with
  WSDL.
• Java2WSDL tool
• Build WSDL from Java classes.
• What we will do today
• Use Java2WSDL to create WSDL based on Server
  written in Java. Create client using WSDL2Java.

25
Java2WSDL

• Generate the WSDL description based on the server
  interface
• java org.apache.axis.wsdl.Java2WSDL -o
  adamcalc.wsdl -l http//localhost8080/axis/serv
  ices/AdamCalcService -n urnposwolskyFoo
  AdamCalcServiceClass

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Output adamcalc.wsdl (1/4)

• ltwsdltypesgt
• ltschema targetNamespace"urnposwolskyfoo"
  xmlns"http//www.w3.org/2001/XMLSchema"gt
• ltimport namespace"http//schemas.xmlsoap.org/s
  oap/encoding/"/gt
• ltcomplexType name"ArrayOf_soapenc_string"gt
• ltcomplexContentgt
• ltrestriction base"soapencArray"gt
• ltattribute ref"soapencarrayType"
  wsdlarrayType"soapencstring"/gt
• lt/restrictiongt
• lt/complexContentgt
• lt/complexTypegt
• lt/schemagt
• lt/wsdltypesgt

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Output adamcalc.wsdl (2/4)

• ltwsdlmessage name"binary2IntResponse"gt
• ltwsdlpart name"binary2IntReturn"
  type"xsdint"/gt
• lt/wsdlmessagegt
• ltwsdlmessage name"binary2IntRequest"gt
• ltwsdlpart name"in0" type"soapencstring"/
  gt
• lt/wsdlmessagegt
• ltwsdlmessage name"int2BinaryRequest"gt
• ltwsdlpart name"in0" type"xsdint"/gt
• lt/wsdlmessagegt
• ltwsdlmessage name"int2BinaryResponse"gt
• ltwsdlpart name"int2BinaryReturn"
  type"soapencstring"/gt
• lt/wsdlmessagegt
• ltwsdlmessage name"mainRequest"gt
• lt/wsdlmessagegt

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Output adamcalc.wsdl (3/4)

• ltwsdlportType name"AdamCalcServiceClass"gt
• ltwsdloperation name"binary2Int"
  parameterOrder"in0"gt
• ltwsdlinput message"implbinary2IntReque
  st" name"binary2IntRequest"/gt
• ltwsdloutput message"implbinary2IntResp
  onse" name"binary2IntResponse"/gt
• lt/wsdloperationgt
• ltwsdloperation name"int2Binary"
  parameterOrder"in0"gt
• ltwsdlinput message"implint2BinaryReque
  st" name"int2BinaryRequest"/gt
• ltwsdloutput message"implint2BinaryResp
  onse" name"int2BinaryResponse"/gt
• lt/wsdloperationgt
• lt/wsdlportTypegt

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Output adamcalc.wsdl (4/4)

• ltwsdlbinding name"AdamCalcServiceSoapBinding
  type"implAdamCalcServiceClass"gt
• ltwsdloperation name"binary2Int"gt
• ltwsdlsoapoperation soapAction""/gt
• ltwsdlinput name"binary2IntRequest"gt
• ltwsdlsoapbody encodingStyle"http//s
  chemas.xmlsoap.org/soap/encoding/"
  namespace"urnposwolskyfoo" use"encoded"/gt
• lt/wsdlinputgt
• .
• lt/wsdloperationgt
• lt/wsdlbindinggt
• ltwsdlservice name"AdamCalcServiceClassService
  "gt
• ltwsdlport binding"implAdamCalcServiceSoap
  Binding" name"AdamCalcService"gt
• ltwsdlsoapaddress location"http//localh
  ost8080/axis/services/AdamCalcService"/gt
• lt/wsdlportgt
• lt/wsdlservicegt

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WSDL2Java (client stubs)

• Automated Tool to create Java client stub based
  on WSDL
• java org.apache.axis.wsdl.WSDL2Java
  adamcalc.wsdl
• What is created?
• AdamCalcServiceClass.java
• Java Interface (fun. declaration of binary2Int,
  int2Binary)
• AdamCalcServiceClassService.java
• Service Interface (e.g. getAdamCalcServiceAddress)
  
• AdamCalcServiceClassServiceLocator.java
• Implementation of Service Interface (Automatic)
• AdamCalcServiceSoapBindingStub.java
• Your client will use this to make requests to
  Service.
• Details available at
• http//ws.apache.org/axis/java/user-guide.html

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What is the purpose of a Stub?

• A Stub contains the code which turns the method
  invocations into SOAP calls.
• It stands in as a proxy (another term for the
  same idea) for the remote service, letting you
  call it exactly as if it were a local object.

32
Example Client

• import poswolskyfoo.
• public class adamClient
• public static void main(String args)
• try
• AdamCalcServiceClassService service
• new AdamCalcServiceClassServiceLocator()
• AdamCalcServiceClass calc
• service.getAdamCalcService()
  
• // Convert input binary string to an
  integer.
• int result calc.binary2Int(args0)
• System.out.println(args0 " is "
  result)
• catch (Exception e) e.printStackTrace()

33
Server Creation from WSDL

• We also have tool support to create a server from
  the WSDL.
• java org.apache.axis.wsdl.WSDL2Java --server-side
  --skeletonDeploy true adamcalc.wsdl
• Skeleton Description
• The skeleton class is the class that sits between
  the Axis engine and the actual service
  implementation. Its name here would be
• AdamCalcServiceSoapBindingSkeleton.java
• Just need to fill out
• AdamCalcServiceSoapBindingImpl.java
• Hides SOAP details!
• Tool also creates a deploy.wsdd

34
Installation of Apache Axis

• At least how I got it to work

35
Installing Apache Axis (1/2)

• http//ws.apache.org/axis/java/install.html
• Download axis
• http//www.apache.org/dyn/closer.cgi/ws/axis/1_4
• Download XML Parser (Xerces)
• http//xml.apache.org/dist/xerces-j/
• Download JavaBeans Activation Framwork (JAF)
• http//java.sun.com/products/javabeans/jaf/
• Download JavaMail
• http//java.sun.com/products/javamail/
• Optionally download XML Security
• http//xml.apache.org/security/

36
Installing Apache Axis (2/2)

• Copy ltaxisgt/webapps/axis to lttomcatgt/webapps/axis
• ltXgt stands for installation path of X..
• Copy ltaxisgt/lib/ and all jar files from
  additional packages to both
• lttomcatgt/common/lib
• lttomcatgt\webapps\axis\WEB-INF\lib
• This may be overkill, but this is how I got it to
  work.
• Restart Tomcat and try to go to
  http//localhost8080/axis/
• And verify by clicking Validation

37
Running Apache Examples

• My Classpath includes
• ...\axis.jar
• ...\axis-ant.jar
• ...\commons-discovery-0.2.jar
• ...\commons-logging-1.0.4.jar
• ...\jaxrpc.jar
• ...\mail.jar
• ...\resolver.jar
• ...\saaj.jar
• ...\tools.jar
• ...\wsdl4j-1.5.1.jar
• ...\xercesImpl.jar
• ...\xml-apis.jar
• ...\xmlsec-1.2.1.jar
• ...\activation.jar
• ltaxisgt
• For sample code

38
Axis Administration

• http//localhost8080/axis
• Axis Admin client
• Java org.apache.axis.client.AdminClient
• Deploy Services
• Remove Services
• List Services
• Etc

39
Service Registry

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Java way (UDDI4j)

• UDDI4J is a Java class library that provides an
  API that is can be used to interact with a UDDI
  registry. This class library generates and parses
  messages sent to and received from a UDDI server
• http//www.uddi4j.org/

41
Examples with Stylus Studio

• Demonstration to search for Services.
• Demonstration to use Services
• Via SOAP messages.
• Other demonstrations

42
Please Evaluate Us

• One Vote can make a difference!

43
They like meThey like me not

• ITU Course Evaluation
• From Monday 13 Nov. until Monday 27 Nov.
• On your own or lab computer!
• You should have received an email
• Dedicated rooms at ITU
• From 9-12 use Room 4A58
• From 16-18 use Room 2A52
• Why bother?
• Help us/administration ensure you receive a
  quality education.
• What are we doing right? What are we doing
  wrong?
• Things can change based on your feedback.
• We can use your feedback to make the rest of the
  course better.

44
Your Work
45
Mini Project 2

• Mini Project 2 is due tomorrow!
• November 15th, 1200
• Questions/Comments/Concerns?

46
Exercises

• http//www.itu.dk/courses/IWSJ/E2006/exercises/10
  .html