J2EE Ws Apis

8/3/2019 J2EE Ws Apis

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J2EE 1.4 APIs ForWeb Services

Michael D. Thomas

[email protected]


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Agenda

Quick Tour Of J2EE APIs

Service Oriented Architecture

SOAP & WSDL: The 10 minute guide JAX-RPC

SAAJ

JAXP JAXR


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A Simple Example

Company has web app that looks up invoices

The customers like it

Customer wants to pass the data automatically to

another application Typical situation for a web service

Will do it with:1. Straight XML (JAXP)

2. SAAJ: Wrapper around SOAP and HTTP3. JAX-RPC: Uses SOAP and WSDL, but you never have

to see it


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Invoice Screen


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Invoice App Structure


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Invoice JSP

Invoice

Continued . . . .


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Invoice JSP


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Invoice Helper

package org.ibiblio.mdthomas.ws.autopartssupplier;import java.rmi.Remote;import java.rmi.RemoteException; public class InvoiceHelper {

long id;InvoiceBusinessDelegate invoiceBusinessDelegate;

public InvoiceHelper () {invoiceBusinessDelegate =BusinessDelegateFactory.getInvoiceBusinessDelegate();}

public void setInvoiceId (long id) {this.id = id; }

public long getInvoiceId() {

return id;}public InvoiceBean getInvoiceById() {return invoiceBusinessDelegate.getInvoiceById(this.id);}

public InvoiceBean getInvoiceById(long id) {return invoiceBusinessDelegate.getInvoiceById(id);}

}


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InvoiceBean (incomplete) package org.ibiblio.mdthomas.ws.autopartssupplier;

public class InvoiceBean implements Serializable {private CustomerBean customer;private InvoiceItemBean invoiceItems[];private long invoiceId;private float total;private float shippingCharge;private float subTotal;

public InvoiceBean() {}public float getTotal() {

return total;}public void setTotal(float total) {

this.total = total;}public void setCustomer(CustomerBean customer) {

this.customer = customer;}public CustomerBean getCustomer() {

return customer; }

public InvoiceItemBean[] getInvoiceItems() {return invoiceItems;}

public void setInvoiceItems(InvoiceItemBean items[]) {this.invoiceItems = items;}

}


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New XML Architecture


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XML Invoice


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XML Invoice JSP

Continued . . .


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Web Services Requestorpublic static void main(String[] args) throws Exception {

long invoiceId = 0;if (args.length>0) {invoiceId = Long.parseLong(args[0]);}

// Create the URL and encode the invoiceId paramString base =

"http://localhost:8080/jsp-examples/ch03/invoiceAsXml.jsp?";String invoiceParam = "invoiceId="+invoiceId+"&";URL invoiceURL = new URL(base+invoiceParam);

// Connect to the URLURLConnection conn = invoiceURL.openConnection();conn.connect();

// Get the result and create the XMLInputStream invoiceStream = conn.getInputStream();DocumentBuilderFactory dbf =

DocumentBuilderFactory.newInstance();DocumentBuilder db = dbf.newDocumentBuilder();

Document doc = db.parse(invoiceStream);

// Handle the XMLhandleXML(doc);

}


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Web Services Requestorprivate static void handleXML(Document doc) {

float invoiceTotal = 0f;int totalQuantities = 0;float shippingCharge =0f;

Element docRoot = doc.getDocumentElement();

NodeList children = docRoot.getChildNodes();

for (int i=0;i


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Basic XML Web ServicesIssues

Satisfies the business requirement

Not standards baseddoesnt use SOAP orWSDL

Had to handle HTTP directly


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SAAJ & SOAP Approach

Uses SOAP standard

Similar to previous example, but requestorhandles SOAP details

SOAP: data (Body) and meta-data (Header)

Contained in a SOAP envelope

Can attach data outside of the SOAP

envelope SAAJ: handles HTTP requests, wraps JAXP

in SOAP specific nature (like JDOM)


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SOAP Request

POST /invoice-jaxrpc/invoice HTTP/1.1Content-Type: text/xml; charset="utf-8"Content-Length: 246SOAPAction: ""Cache-Control: no-cachePragma: no-cacheUser-Agent: Java/1.4.2

Host: localhost:9090Accept: text/html, text/xml, image/gif, image/jpeg, *; q=.2, */*; q=.2Connection: keep-alive

9845


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SOAP Request



9845


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SOAP Request



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SOAP Response (incomplete)HTTP/1.1 200 OKX-Powered-By: Servlet/2.4SOAPAction: ""Content-Type: text/xml; charset="utf-8"Transfer-Encoding: chunkedDate: Sun, 23 Nov 2003 16:00:17 GMTServer: Sun-Java-System/JWSDP-1.3

data9845data

continued


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SAAJ Providerpublic class InvoiceSAAJProvider extends HttpServlet {

MessageFactory messageFactory;public void doPost (HttpServletRequest request,

HttpServletResponse response)throws ServletException, IOException {

response.setContentType("text/xml");response.setBufferSize(8192);OutputStream out = response.getOutputStream();try {

// initialize the messageFactory

messageFactory = MessageFactory.newInstance();// Get the requested invoicelong invoiceId = getInvoiceId(request);InvoiceHelper invoiceHelper = new InvoiceHelper();InvoiceBean invoice = invoiceHelper.getInvoiceById(invoiceId);

// Create the SOAP output messageSOAPMessage outputMessage = createOutputSOAPMessage(invoice);

// Write the output SOAP message to the response output stream

outputMessage.writeTo(out);

} catch (Exception ex) {ex.printStackTrace();

}out.close();

}


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SAAJ Providerprivate long getInvoiceId(HttpServletRequest request) throws

SOAPException, IOException {// create the input SOAP message from the request's inputStream

MimeHeaders mimeHeaders = getMimeHeaders(request);InputStream inputStream = request.getInputStream();SOAPMessage inputMessage =

messageFactory.createMessage(mimeHeaders,inputStream);

// get the SOAP bodySOAPPart inputPart = inputMessage.getSOAPPart();SOAPEnvelope inputEnvelope = inputPart.getEnvelope();SOAPBody inputBody = inputMessage.getSOAPBody();// get the invoice id as a StringName getInvName = inputEnvelope.createName("getInvoiceById",

null,"http://www.ibiblio.org/mdthomas/invoice/types");

Iterator it = inputBody.getChildElements(getInvName);SOAPElement getInvoiceElem = (SOAPElement)it.next();

Name idName = inputEnvelope.createName("long_1"));it = getInvoiceElem.getChildElements(idName);SOAPElement invoiceIdElem = (SOAPElement)it.next();

// convert to a long and returnString invoiceIdStr = invoiceIdElem.getValue();long invoiceId = Long.parseLong(invoiceIdStr);return invoiceId;

}


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Creating outputprivate SOAPMessage createOutputSOAPMessage(InvoiceBean invoice)

throws SOAPException {// Create a message

SOAPMessage outputMessage = messageFactory.createMessage();SOAPPart outputSoapPart = outputMessage.getSOAPPart();SOAPEnvelope outputEnvelope = outputSoapPart.getEnvelope();outputEnvelope.addNamespaceDeclaration("ns0",

"http://www.ibiblio.org/mdthomas/invoice/types");

// Get the SOAP header from the message and remove itSOAPHeader header = outputMessage.getSOAPHeader();header.detachNode();// Get the SOAP body from the messageSOAPBody body = outputMessage.getSOAPBody();

// Add the top level elementsName responseName = outputEnvelope.createName(

"getInvoiceByIdResponse","ns0",null);

SOAPElement invoiceElem = body.addBodyElement(responseName);SOAPElement resultElem = invoiceElem.addChildElement("result");

// add the invoice idSOAPElement invoiceIdElem = resultElem.addChildElement("invoiceId");long invoiceId = invoice.getInvoiceId();invoiceIdElem.addTextNode(String.valueOf(invoiceId));


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Creating output (incomplete)//add invoice itemsInvoiceItemBean items[] = invoice.getInvoiceItems();for (int i=0;i


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Creating output (incomplete)

// save and return

outputMessage.saveChanges();

return outputMessage;}

SAAJ R t


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SAAJ Requestor

public static SOAPMessage createSOAPRequest(longinvoiceId)

throws SOAPException {// Create message factory

MessageFactory messageFactory =

MessageFactory.newInstance();// Create a messageSOAPMessage message =messageFactory.createMessage();SOAPPart soapPart = message.getSOAPPart();SOAPEnvelope envelope = soapPart.getEnvelope();

SAAJ R t


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SAAJ Requestor

// Get the SOAP header from the message and remove itSOAPHeader header = message.getSOAPHeader();header.detachNode();// Get the SOAP body from the messageSOAPBody soapBody = message.getSOAPBody();// create the outer invoice element

Name getInvoiceName =envelope.createName("getInvoiceById",

null,"http://ibiblio.org/invoice/types");

SOAPBodyElement getInvoiceElem =soapBody.addBodyElement(getInvoiceName);

SAAJ R t


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SAAJ Requestor

// create the invoice parameterName invoiceIdName =envelope.createName("long_1",null,"");SOAPElement invoiceIdElem =

getInvoiceElem.addChildElement(invoiceIdName);

invoiceIdElem.addNamespaceDeclaration("","");invoiceIdElem.addTextNode(String.valueOf(invoiceId));

message.saveChanges();

return message;}


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SAAJ Code Problems

Compliant with SOAP

Still havent done anything with WSDL

Lots and lots of XML creation and parsing

Absolutely no error checking not evensimple type checking

Have to handle all interoperability problems


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JAX-RPC

JAX-RPC Requestor Runtime JAX-RPC Provider Runtime

HTTP Client HTTP Server

Stubs Ties

Servant

ServiceEndpointInterface

ProviderApplication

Logic

RequestorApplication

Logic

SOAP

Generated

Code

Generated

Code

JAX-RPC Service Endpoint


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JAX-RPC Service EndpointInterface

package org.ibiblio.mdthomas.ws.autopartssupplier;

import java.rmi.Remote;

import java.rmi.RemoteException;

public interface InvoiceWebService extends Remote{

public InvoiceBean getInvoiceById(long id)

throws RemoteException;

}


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JAX-RPC Servant

public class InvoiceHelperimplements InvoiceWebService {

// existingcode

}


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Run the tools

SEI-to-WSDL tool and WSDL-to-SEI tool arerequired by JAX-RPC specification

Wscompile and wsdeploy with the Java Web

Services Development Pack from Sun

Java2WSDL with Apache Axis


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Web Service home page


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Web Service WSDL

JAX RPC Requestor


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JAX-RPC Requestor

public static void main(String[] args) {

try {// Get the web service port

InvoiceWebService_Service wsDef =new InvoiceWebService_Service_Impl();

InvoiceWebService_PortType stub =wsDef.getInvoiceWebServicePort();

// Create the input parameterGetInvoiceById idWrapper = new GetInvoiceById(1000);

// Make the remote call to the web serviceGetInvoiceByIdResponse invoiceWrapper =

stub.getInvoiceById(idWrapper);

// Unwrap the resultInvoiceBean invoice = invoiceWrapper.getResult();// Print some dataCustomerBean customer = invoice.getCustomer();System.out.println("Customer: "+customer.getName());InvoiceItemBean items[] = invoice.getInvoiceItems();for (int i=0;i


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JAX-RPC Requestor

public static void main(String[] args) {

try {// Get the web service port

InvoiceWebService_Service wsDef =new InvoiceWebService_Service_Impl();

InvoiceWebService_PortType stub =wsDef.getInvoiceWebServicePort();

// Create the input parameter

GetInvoiceById idWrapper = new GetInvoiceById(1000);// Make the remote call to the web serviceGetInvoiceByIdResponse invoiceWrapper =

stub.getInvoiceById(idWrapper);

// Unwrap the resultInvoiceBean invoice = invoiceWrapper.getResult();// Print some data

CustomerBean customer = invoice.getCustomer();System.out.println("Customer: "+customer.getName());InvoiceItemBean items[] = invoice.getInvoiceItems();for (int i=0;i


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.NET C# Requestor

Generate C# requestor based on WSDL:

>wsdl.exe /language:CS /protocol:SOAP \

http://localhost:8080/invoice/jaxrpc/invoice?WSDL

Entry point:

public getInvoiceByIdResponse getInvoiceById([System.Xml.Serialization.XmlElementAttribute("getInvoiceById",

Namespace="http://www.ibiblio.org/mdthomas/invoice/types")]getInvoiceById getInvoiceById1) {

object[] results = this.Invoke("getInvoiceById",new object[] {getInvoiceById1});

return ((getInvoiceByIdResponse)(results[0]));}

NET C# Requestor
http://localhost:8080/invoice-jaxrpc/invoice?WSDLhttp://localhost:8080/invoice/jaxrpc/invoice?WSDLhttp://localhost:8080/invoice/jaxrpc/invoice?WSDLhttp://localhost:8080/invoice-jaxrpc/invoice?WSDL


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.NET C# Requestorclass JAXClient {

[STAThread]static void Main(string[] args) {

// Create the stubInvoiceWebService service = new InvoiceWebService();// Set the endpointif (args.Length == 1)

service.Url = args[0];elseservice.Url = "http://localhost:8080/invoice-jaxrpc/invoice";

// create and send the requestgetInvoiceById idWrapper = new getInvoiceById();idWrapper.long_1 = 1000;getInvoiceByIdResponse responseWrapper = service.getInvoiceById(idWrapper);

// Receive and process the result

InvoiceBean invoice = responseWrapper.result;Console.WriteLine("Invoice id: "+invoice.invoiceId);CustomerBean customer = invoice.customer;Console.WriteLine("Customer: "+customer.name);

for (int i=0;i


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Web Services Architecture

Web Services as a presentation layertechnology

Service Oriented Architecture (SOA) & Web

Services

Message Exchange Patterns (MEPs)

RPC centric vs. Document centric

approaches Relevant SOAP & WSDL details

Web Services And


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Presentation Layer

Web Services And


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Presentation Layer

Fallacies Of Distributed


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Computing (Peter Deutch)

The network is reliable

Latency is zero

Bandwidth is infinite The network is secure

Topology doesnt change

There is one administrator

Transport cost is zero

The network is homogeneous

Waldo On Distributed


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Computing

work in distributed object-oriented systemsthat is based on a model that ignores ordenies [the differences between local and

remote objects] is doomed to failure, andcould easily lead to an industry-wide rejectionof the notion of distributed object-basedsystems."

-- Jim Waldo et al, A Note on DistributedComputing, 1994

Local objects are different than


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jremote objects

Local objects are different than remoteobjects because:

Different address spaces (by reference vs. by

copy) Latency

Partial failure

Concurrency

Service Oriented Architecture


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(SOA)

Services have network interfaces

Service providers and consumers are looselycoupled

Interfaces are coarse grained

Location is transparent

Services can be looked up in a registry

Consumer can bind to a provider at runtime


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SOA applied to EJBs

EJBs do distributed computing

J2EE patterns that promote SOA tenets:

Session Faade pattern with Value Objects for

bind and execute

Service Locator pattern for find


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SOA Applied to EJBs

EJB Container JVMServlet Container JVM

HttpServlet

PresentationProcessor

ServiceLocator

BusinessDelegate

SessionEJBSessionFacade EntityEJB

EntityBean

JavaBeanValueObject

local access

uses

locates

SessionFacadeRemote proxy for

returns

returns


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SOA Applied To Web Services

WebServicesRequestor UDDIProxy WebServiceProvider

Find WSDL

RequestorValueObject

BusinessLogicObject

SOAP Request

ProviderValueObject

Execute Business Logic

Create

SOAP Response (Value Obj. as XML)

Read

Create

Read


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Message Exchange Patterns

Message Exchange Patterns (MEPs): howmessages are exchanged

There are really two:

Request-response

One way

WSDL defines two others, notification and

solicit response, which arent supported byJ2EE and arent widely used

Code to MEPs, not to the underlying protocol


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Request-response over HTTP


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One way MEP over HTTP

Request-response MEP over


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SMTP

RPC Centric vs. DocumentC i


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Centric

RPC Centric: Web services transmit objectsas XML

Document Centric: Web services transmit

XML documents. Applications on either endcreate and parse XML documents

RPC is more closely associated with therequest-response MEP

Document centric is more closely associatedwith the one way MEP

D C i A h


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Document Centric Approach

RPC C t i A h


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RPC Centric Approach

RPC D d J2EE


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RPC vs. Doc and J2EE

JAX-RPC is an RPC centric approach JAXM is document centric

SAAJ is low-level document centric by default

Document centric is best when you are really

dealing with documents newsfeeds for example Doesnt make sense to change XML to objects

back to XML again Usually, you want to deal with objects, not XML

However: Business tends to think in documents (P.O., Invoice) Documents are more naturally coarse grained

WSDL & SOAP


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WSDL & SOAP

SOAP wire-line protocol

SOAP envelope, body and headers: Body: Just transporting the data

Header: Meta-data. Higher standards use headers

Envelope: just a container

WSDL describes the web service

Similar to Java method signatures

WSDL is very interesting Helps to understand WSDL to do JAX-RPC

Can go a long way with JAX-RPC without knowinganything about SOAP

WSDL compared to Java


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WSDL compared to Java

WSDL Port Type(Java Interface)

WSDL Operation(Java Method)

WSDL Message(Java Parameter)

WSDL Operation(Java Method)

WSDL Message(Java Parameter)

WSDL Type(Java ValueObject Type)

WSDL Type(Java ValueObject Type)

WSDL


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PortType

Binding

Operation Message

Type

1 *

1

*

XSD Type

1

*

SOAP:Binding

Encoding

Literal XML SOAP Section 5 Encoding

1

*

uses

1

*

specifies

Service

Port

SOAP:Address URI11

Style

Document Style RPC Style

specifies

1 1

1

*

1

*

uses

Interoperability Challenges


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Interoperability Challenges

Interoperability is the chief challenge of webservices

Tools generating SOAP, WSDL, UDDI, etc. need

to be interoperableA more complex variation of the Browser Wars of

the 1990s

Web Services Interoperability (WS-I) dedicated to

Interoperability

WS-I Basic Profile 1.0 declares an interoperableweb services platform

WS I Basic Profile


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WS-I Basic Profile

WS-I Basic Profile 1.0:

SOAP 1.1

WSDL 1.1

Must use HTTP binding, should use HTTP 1.1 XML Schema Part 1, Part 2

May use HTTPS

SOAP messages should use document/literalSimilar to the J2EE certification program

JAX-RPC


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Big selling point: Never have to program against

SOAP

Big value add: Generated code (not the APIs)

Addresses interoperability problems because the

code generators can adhere to WS-I Basic Profile1.0

Uses Faade and Value Object patterns

RPC-centric, though you can start with definedWSDL and XSD

Tends to use request-response MEP, but canwork with one-way MEP

JAX RPC


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JAX-RPC

JAX-RPC Requestor RuntimeJAX-RPC Provider Runtime

HTTP Client HTTP Server

Stubs Ties

Servant

Service

EndpointInterface

ProviderApplication

Logic

RequestorApplication

Logic

SOAP

Message Handlers

CustomType

Handlers

CustomType

Handlers

Message Handlers

ServiceEndpointInterface

JAX-RPC Interoperability


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JAX-RPC Interoperability

JAX-RPC

Requestor

Non JAX-RPCRequestor

JAX-RPC

Provider

Non JAX-RPCProvider

JAX-RPC SEI-first ProviderDevelopment


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Development

Service Endpoint Interface first web servicesenabling existing Java code

1. Define a Service Endpoint Interface

2. Implement the Servant ties to businesslogic

3. Generate WSDL with JAX-RPC

4. Create WAR5. Deploy to servlet container

JAX-RPC SEI-first ProviderDevelopment


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Development

JAX-RPC RequestorDevelopment


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p

1. Point at the WSDL file2. Generate stubs

3. Code against the stubs

Stubs mirror the WSDL entities The SEI is generated for the requestor side

Value objects are generated

SEI and value objects are usually in a different

package Can generate a JAX-RPC Requestor against

non JAX-RPC generated WSDL documents

JAX-RPC RequestorDevelopment


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Development

JAX-RPC WSDL-firstDevelopment


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Development

1. Point to the WSDL

2. Generate SEI, value objects

3. Code Servant

4. Generate Ties

5. Create WAR

6. Deploy to servlet container

WSDL generated Java


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WSDL generated Java

WSDL supersets Java in several areas

Can define multiple OUT and IN/OUT parameters

JAX-RPC uses holder objects for these

Can define one-way operations WSDL can do stronger typing than Java (e.g.,

regular expression facets)

Headers can be mapped as explicit context to an

SEI call a header will be passed to the SEI

method as a parameter

Service Endpoint Interfaces(SEIs)


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(SEIs)

1. Must extend java.rmi.Remote

2. Every method must throw RemoteException

3. No constant declarations

4. Parameters and return types must be validJAX-RPC types

#4 is the big one

JAX-RPC Types


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JAX RPC Types

XML (and thus web services) is data-centric notobject-centric

Valid JAX-RPC types are what could beconsidered value types

Java primitives and primitive wrappers (int,Integer, long, Long, etc.)

Some standard Java classes (e.g., String, Date)

Java value types (method-less Java classes or,roughly, JavaBeans)

Arrays

JAX-RPC Standard Types


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JAX RPC Standard Types

java.lang.String

java.math.BigInteger

java.math.BigDecimal

java.util.Calendar

java.util.Date

java.xml.namespace.QName

java.net.URI

Value Object Types


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a ue Object ypes

Default no object constructor

Must not implement Remote

Methods are notmapped to the transmitted

XML Java Bean properties and public, non-final,

non-static fields are mapped

Fields/properties can be any valid JAX-RPCtype

Value Object


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j

public class PersonValueType {public String name;public Date birthDate;public boolean smoker;

public String sex;public int cholestrolLevel;public URI webSite;public PersonValueType mom;public PersonValueType dad;

public PersonValueType children[];}

Exceptions & SOAP Faults


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p

Can declare exceptions in an SEI

Will declare an equivalent fault in the WSDLfile

Exception will be thrown on the requestorwhen a fault is received

Exceptions in the SEI must not extend

RuntimeException

JAX-RPC Polymorphism


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y p

Subtypes of a declared return type can bereturned

Must tell the code generation tool about the

sub-types if they dont appear elsewhere inthe SEI

WSDL supports extensible types

Can downcast in the JAX-RPC requestorcode

Handlers


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JAX-RPC message handlers give you a wayto access a SOAP message before or afterits ultimate processing

Handler interface has three methods: handleRequest

handleResponse

handleFault

JAX-RPC Handlers


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NetworkRequestor

App.Servant

Handler1

Handler2

Handler

4

Handler

3

ServletEndpointInterface


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ServletEndpointInterface provides access to theunderlying servlet context

Can use it inside a JAX-RPC servant to: Get/set values to an HTTPSession

Interface with HTTP authentication Get resources

Be careful: SOAP is designed to be transport (i.e., HTTP)

independent (but WS-I says its okay to use HTTP

cookies) The requestor must support cookies and behave

correctly! (Not the same as assuming a web browserwill behave correctly)

ServletEndpointContext


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public class HttpAccessServant implements HttpAccess, ServiceLifecycle{

ServletEndpointContext context;

public void init(Object o) {context = (ServletEndpointContext)o;

}

public void destroy() {}

public void setHttpSessionAttribute(String key, String val)throws RemoteException {HttpSession session = context.getHttpSession();session.setAttribute(key,val);

}}

2.1 Stateless Session Beansand Web Services


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EJB 2.1 specifies that Stateless SessionBeans may declare a SEI

Similar to a remote component interface

EJB container is a JAX-RPC runtimemanages requests to the SEI

One step simpler than a servlet based SEI

that accesses the Stateless Session Beanthrough a Session Faade pattern

Differences Between Servlet JAX-RPC & EJB Container JAX-RPC


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Different network architecture: May not wantoutside HTTP connections to the EJBContainer

Differences in transport implementation EJB 2.1 does notrequire that the EJB

container support HTTP sessions

Static vs. Dynamic Requestors


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Static proxy: Use stubs generated by WSDL-to-Java tool at compile time

Dynamic proxy: Use proxy created at runtime,though SEI is generated at compile time

Dynamic Invocation Interface (DII): Completelydynamic. Signature of web service and WSDLdoesnt need to be known until runtime

Requestors and providers are usually

somewhat coupled at compile time, even if youuse DII

Apache Axis


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Axis is a web services engine Implements JAX-RPC 1.1, SAAJ 1.2

specification

Axis details beyond J2EE standards: JWS deployment similar to JSP

WSDD for deploying web services

Currently, some weaknesses in supporting

WS-I Basic Profile (e.g., document/literal) Should be addressed soon

SAAJ


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SAAJ is a wrapper for XML parsing and canhandle HTTP calls

SAAJ provides convenience methods for

accessing the SOAP envelope, headers andbody

Similar to JDOM

Can bridge to W3C DOM APIs

JAXM & Messaging


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JAXM is an asynchronous, queue-basedmessaging API

Notpart of J2EE 1.4

Uses queues on either side Doesnt provide WSDL facilities

Can be used in conjunction with JAXB to

convert to objects

JAXR


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JAXR API for XML registries Generic: Can be used with any XML registry

Support for UDDI and ebXML

Has support for querying and for publishing

Publishing requires authentication

Can set up your own private UDDI registries

that act as a naming service

Conclusions


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JAX-RPC: quickest solution for synchronous, RPCstyle web services and for service-enablingexisting code

RPC model isnt always best if its too finegrained it violates SOA

SOA coarse grained, loosely coupled interfaces

JAXP Avoid if possible. Use JAXB/Castor totranslate into an object model

JAXM Good for message style services

SOAP & WSDL WSDL is more interesting JAXR Used for access to XML Registries (i.e.,

UDDI)