WebSphere Application Server - Overvie Application Server ... Technical Sales Specialist IBM Italia...
Transcript of WebSphere Application Server - Overvie Application Server ... Technical Sales Specialist IBM Italia...
IBM Italia SpA
© 2007 IBM Corporation| Milan, 07 January 2008 |
WebSphere Application Server - Overview
Marco DragoniIBM Software Group – Technical Sales Specialist
IBM Italia S.p.A.
IBM Value Assessment
© Copyright IBM Corporation 2007
2
Agenda
� Course and speaker introduction
� What is an Application Server
� Model-View-Controller Pattern
� WebSphere Basic Architecture and mapping to MVC
– EAR file composition
– J2EE standard
– WebSphere Application Server Family
� Understand difference between Basic and Network Deployment
– Accessing Application Server Resource
– A typical application flow
� HTTP Server and Plug-in
� Class Loader role
� JNDI role
� JDBC resource
� Web Services for J2EE
IBM Value Assessment
© Copyright IBM Corporation 2007
3
Course and Speaker Introduction
� 7 January 2008 (14.30-16.30) – WebSphere Application Server Overview (Marco
Dragoni)
� 11 January 2008 (11.30-13.30) – Order Process demonstration (Marco Dragoni).
Service Oriented Architecture Introduction (Mariano Ammirabile)
� 14 January 2008 (14.30-16.30) – WebSphere Integration Developer Introduction
(Marco Dragoni)
� 16 January 2008 (14.30-17.30) LAB 01 – Building a simple service-oriented application (BSM and BPEL)
� 18 January 2008 (11.30-13.30) – WebSphere Process Server, WebSphere
Enterprise Service Bus and WebSphere Service Registry and Repository Overview (Marco Dragoni)
� 23 January 2008 (10.30-13.30) LAB 02 – BO mapping, Human Task and
Selector component
IBM Value Assessment
© Copyright IBM Corporation 2007
4
What is an Application Server
� An Application Server is a runtime environment for hosting applications that are written following the J2EE specification
� An Applications Server, compliant with J2EE specification, offers services such as Security (JASS), Transaction (JTA), Messaging (JMS), Naming Services (JNDI), Database Connectivity (JDBC), etc.
� Any Web applications that are written to the J2EE specification can be installed and deployed on the server
� J2EE is:
– An open and standard based platform for developing, deploying and managing n-tier, Web-enabled, server-centric, and component-based enterprise applications
� J2EE add value to
– Developer
– Vendors
– Business Customer
IBM Value Assessment
© Copyright IBM Corporation 2007
5
J2EE – MVC Pattern (Model View Controller)
� Model to represent the underlying
data and business logic behaviuor in one place (Entity and Session
EJB). Make data and behaviour
independent from presentation. Represented by EJB.
� View display information
according to client types, display result of business logic.
Represented by JSP.� Controller serves as the logical
connection between the users
interaction and the business
services on the back.
Represented by Servlet.
IBM Value Assessment
© Copyright IBM Corporation 2007
6
J2EE Architecture
Web Tier EJB Tier
� The Presentation Tier processes input from the Client Side Tier, calls components
in the Business Logic Tier, and then sends a response back to the Client Side Tier
(Servlet, JSP)� The Business Logic Tier provides a framework for executing business logic and
for accessing business data in a distributed transactional environment (EJB)
IBM Value Assessment
© Copyright IBM Corporation 2007
7
Web Applications and anatomies
� It is often advantageous to treat each layer as an independent portion of your application
� Do not confuse logical separation of responsibilities with actual separation of components
� Some of the layers can be combined into single components to reduce
application complexity
� J2EE application anatomies samples:
– HTML client, JSP/Servlets, EJB, JDBC/Connector (4 tiers)
– HTML client, JSP/Servlets, JDBC (3 tiers)
– EJB standalone applications, EJB, JDBC/Connector (3 tiers)
IBM Value Assessment
© Copyright IBM Corporation 2007
8
J2EE 1.4 Application Components
Web Module
HTML
Java beans
Servlet/JSP
DeploymentDescriptor
EJB Module
DeploymentDescriptor
Session
Entity
MDB
ResourceAdapter (RAR)
DeploymentDescriptor
RA JavaClasses
ApplicationClient Module
DeploymentDescriptor
RA JavaClasses
Main Class
DeploymentDescriptor
Runs in Application ServerRuns in ApplicationClient Container
IBM Value Assessment
© Copyright IBM Corporation 2007
9
J2EE 1.4 Standard supported
IBM Value Assessment
© Copyright IBM Corporation 2007
10
WebSphere AS Packaging
WebSphere
Process
Server�Process Choreography
�Business Rules EngineWebSphere
ESB�Mediation Functions
WebSphere XD�Dynamic Operation
�High Performance Computing
�Management Facility
�Clustering
Failover
Workload Mgmt
�Distributed Administration
�Web Services
UDDI Registry
Web Services Gat.
�Edge Components
�IBM Ldap for prod env.
�TAM for prod env.
�DB2 Session Persistance
WebSphere ND
Application Server
Express/Base�Extended Transaction
Support
�Application Profiling
�Asynchronous Execution
�Dynamic Query
�Scheduling
�Startup Beans
�Service Integration Bus
WebSphere CE
Based on Apache
Geronimo
IBM Value Assessment
© Copyright IBM Corporation 2007
11
WebSphere AS Basic Architecture
MessagingEngine
Em
bedded H
TT
PS
erv
er
Web Container
Servlets JSPs
EJB Container
EJBs
ApplicationDatabasesApplicationData
XML Configuration
Files
HTTP Server Plug-in
HTTP Server
Application ServerApplication Server
Plug-in Configuration File
Dynamic Cache Name Server Security
… … ….
Web ServicesEngine
Data Replication JMX Transaction.
HTTP/S
Web Browser
HTTP/S
IBM Value Assessment
© Copyright IBM Corporation 2007
12
WebSphere AS Basic Administration
Application Server
WEB Container
Embedded HTTP Server9060
Administrative Services
Administrative Console
Application
Soap/HTTPor
RMI-IIOP
WebSphereWebSphereAdministrative ClientsAdministrative Clients
Custom Java Administrative
Clients
Scripting Client (wsadmin)
Web Browser
Update
Configuration Repository
Internet or Intranet
ConfigFiles
J2EEApps
(EARs)
Stand-alone Node
� Administrative Console run inside the same JVM running customer
application
IBM Value Assessment
© Copyright IBM Corporation 2007
13
WebSphere AS Express, Base – Sample Topologies
Http Server + WebSphere Plug-in WebSphere AS Database/EIS
HTTP Server
WAS
Database/EIS
� All in one machine
� Easy to maintain
� Low cost
� Low performance
� All in different machine
� A DMZ can be established
� No competition between DB and other resources (different tuning)
DMZ Network Intranet Network
Example 1
Example 2
IBM Value Assessment
© Copyright IBM Corporation 2007
14
WebSphere AS Network Deployment Architecture
� A deployment manager process
manages the node agents
– Holds the configuration repository for
the entire management domain,
called a cell
– Administrative Console runs inside
the DMgr
� A node is a logical grouping of servers
– Each node is managed by a single
node agent process
– A managed node is a node that
contains a node agent
– An unmanaged node is a node in the
cell without a node agent� Enables the rest of the environment to be
aware of the node
V6 Node
V6 Application
Server
V6 Application
Server…
V6 Node
V6 Application
Server
V6 Application
Server…
…
Cell
IBM Value Assessment
© Copyright IBM Corporation 2007
15
Network Deployment : File synchronization
� Deployment manager contains the master configuration
� Node agents synchronize their files with the master copy
� Automatically� At start up� Periodically
� Manually� Administrative console� Command line
� During synchronization� 1. Node agent asks for changes to master configuration� 2. New or updated files are copied to the node
IBM Value Assessment
© Copyright IBM Corporation 2007
16
V6 Node
V6 Application
Server
V6 Application
Server…V6 Node
V6 Application
Server
V6 Application
Server……
ConfigFiles
J2EEApps
(EARs)
ConfigFiles
J2EEApps
(EARs)
ConfigFiles
J2EEApps
(EARs)
Network Deployment : System Administration
Administrative ClientsAdministrative Clients
� ND allows you to manage the entire cell (all processes) from a central Deployment Manager
– Administrative clients connect to Deployment Manager
� Changes made by the administrative clients are saved in the master configuration
� The configuration is then synchronized with the Nodes
Master Configuration forthe Entire Cell
V6 Deployment Manager
WEB Container
Embedded HTTP Server
Administrative Services
Administrative Console
Application
9060Internet
or Intranet
Soap/HTTPor
RMI-IIOP
Custom Java Administrative
Clients
Scripting Client (wsadmin)
Web Browser
ConfigFiles
J2EEApps
(EARs)
IBM Value Assessment
© Copyright IBM Corporation 2007
17
WebSphere AS Example configuration (ND package)
Web Server + Plugin
DMGR
Node Agent
JVM AS
WebSphere
Cluster1
WebSphere Traffic
Client Traffic
LEGENDA
Caching Proxy
Load Balancer
INTERNET DMZ
INTRANET
Internet Client
IBM Value Assessment
© Copyright IBM Corporation 2007
18
Accessing Server Resources
Web browserHTTP(S)
ApplicationDatabasesApplicationData
Messaging Engine
Em
bedded H
TT
PS
erv
er
WebContainer
EJBContainer
Application ServerApplication Server
Web Services Engine
Servlets/JSPs EJBs
Java client
Web Servicesclient
RMI/IIOP SOAP/JMS
SOAP/HTTP(S)
JMS Client
IBM Value Assessment
© Copyright IBM Corporation 2007
19
The flow of an application
IBM Value Assessment
© Copyright IBM Corporation 2007
20
Plug-in configuration file
� The plug-in configuration file (plugin-cfg.xml) contains routing information for
all applications mapped to the Web server. This file is read by a binary plug-in
module loaded in the Web server.
IBM Value Assessment
© Copyright IBM Corporation 2007
21
Plug-in XML tag description
� VirtualHostGroup, VirtualHost: – A group of virtual host names and ports that will be specified in the HTTP Host header when the user
tries to retrieve a page. Enables you to group virtual host definitions together that are configured to handle similar types of requests. The requested host and port number are matched to a VirtualHosttag in a VirtualHostGroup.
� UriGroup, Uri :– A group of URIs that will be specified on the HTTP request line. The incoming client URI is compared
with all the Uri tags in the UriGroup to see if there is a match to determine if the application server will handle the request for the Route in conjunction with a virtual host match.
� Route:– The Route definition is the central element of the plug-in configuration. It specifies how the plug-in
will handle requests based on certain characteristics of the request. The Route definition contains the other main elements: a required ServerCluster, and either a VirtualHostGroup, UriGroup, or both. Using the information that is defined in the VirtualHostGroup and the UriGroup for the Route, the plug-in determines if the incoming request to the Web server should be sent on to the ServerClusterdefined in this Route. The plug-in sets scores for Routes if there is a VirtualHost and Uri match for an incoming request. Once the plug-in processes all Routes, the Route chosen is the one with the highest score.
� ServerCluster, Server:– The located ServerCluster from the Route tag contains a list of Server tags that in turn contain the
requested object. The ServerCluster located by finding the correct Route can optionally specify theWLM algorithm. This will then be used to select one Server from within the ServerGroup.
� Transport:– Once a Server has been located, its Transport tags describe how to connect to it.
IBM Value Assessment
© Copyright IBM Corporation 2007
22
Plug-in workload management policies
� Weighted round robin
– When using this algorithm, the plug-in selects a cluster member at random from which
to start. The first successful browser request is routed to this cluster member and then
its weight is decremented by 1. New browser requests are then sent round robin to
the other application servers and subsequently the weight for each application server
is decremented by 1. The spreading of the load is equal between application servers
until one application server reaches a weight of 0. From then on, only application
servers with a weight higher than 0 will have requests routed to them. The only
exception to this pattern is when a cluster member is added or restarted or when
session affinity comes into play.
� Random
– Requests are passed to cluster members randomly. Weights are not taken into
account as with round robin. The only time the application servers are not chosen
randomly is when there are requests with sessions associated with them. When the
random setting is used, cluster member selection does not take into account where
the last request was handled. This means that a new request could be handled by the
same cluster member as the last request.
IBM Value Assessment
© Copyright IBM Corporation 2007
23
Plug-in configuration file – Session Affinity
� In a clustered environment, any HTTP requests associated with an HTTP
session must be routed to the same Web application in the same JVM.
� This ensures that all of the HTTP requests are processed with a consistent view of the user’s HTTP session.
� The exception to this rule is when the cluster member fails or has to be
shut down.
content valueCache ID 0000Session ID SHOQmBQ8EokAQtzl_HYdxItseparator :Clone ID vuel491u
<?xml version="1.0" encoding="ISO-8859-1"?><!--HTTP server plugin config file
for the cell ITSOCell generated on 2004.10.15 at 07:21:03 PM BST--><Config>......<ServerCluster Name="MyCluster"><Server CloneID="vuel491u" LoadBalanceWeight="2"
Name="NodeA_server1"><Transport Hostname="wan" Port="9080" Protocol="http"/><Transport Hostname="wan" Port="9443" Protocol="https">......</Config>
IBM Value Assessment
© Copyright IBM Corporation 2007
24
Plug-in configuration file – Session Failover
� Server clusters provide a solution for failure of an application server. � Sessions created by cluster members in the server cluster share a common
persistent session store (Memory or Database).
� Any cluster member in the server cluster has the ability to see any user’s session
saved to persistent storage � If one of the cluster members fail, the user can continue to use session information
from another cluster member in the server cluster. This is known as failover.
Failover works regardless of whether the nodes reside on the same machine or
several machines.
IBM Value Assessment
© Copyright IBM Corporation 2007
25
Java Class Loader
� Class loaders enable the Java virtual machine (JVM) to load classes. Given
the name of a class, the class loader locates the definition of this class.
Each Java class must be loaded by a class loader.
� When you start a JVM, you use three class
loaders: the Bootstrap class loader, the
Extensions class loader, and the System class
loader.
� The Extensions class loader is the parent for the System class loader. The Bootstrap class loader is
the parent for the Extensions class loader. The
class loaders hierarchy is shown
� Delegation is a key concept to understand when dealing with class loaders
IBM Value Assessment
© Copyright IBM Corporation 2007
26
ClassLoader behavior example
� A class called WhichClassLoader1 loads a class called
WhichClassLoader2, in turn invoking a class called WhichClassLoader3
� If all WhichClassLoaderX classes are put on the system
class path, the three classes are loaded by the System class loader, and this sample runs just fine.
� Now suppose you package the WhichClassLoader2.class
file in a JAR file that you store under
<JAVA_HOME>/lib/ext directory.
� As you can image, the program fails with a
NoClassDefFoundError exception, which might sound
strange because WhichClassLoader3 is on the system class path. The problem is that it is on the wrong class
path.
IBM Value Assessment
© Copyright IBM Corporation 2007
27
ClassLoader behavior example cont.
� The WhichClassLoader2 class was loaded by the Extensions class loader. In
fact, the System class loader delegated the load of the WhichClassLoader2 class
to the Extensions class loader, which delegated the load to the Bootstrap class
loader. Because the Bootstrap class loader could not find the class, the class loading control was returned to the Extensions class loader. The Extensions
class loader found the class and loaded it.
� Now, the Extensions class loader needs to load the WhichClassLoader3 class. It
delegates to the Bootstrap class path, which cannot find the class, then tries to
load it itself and does not find it either.
� A NoClassDefFoundError exception is thrown. Once a class is loaded by a class
loader, any new classes that it tries to load reuse the same class loader, or go up
the hierarchy to find a class.
� A class loader can only find classes by going up the hierarchy, never down.
IBM Value Assessment
© Copyright IBM Corporation 2007
28
WebSphere Class Loader policies
� The top box in red represents the Java (Bootstrap, Extension and System) class
loaders. WebSphere loads just enough here to get itself bootstrapped and initialize the WebSphere extension class loader.
� The WebSphere extensions class loader is where WebSphere itself is loaded
� EJB modules, utility JARs, resource
adapters files, and shared libraries
associated with an application are always grouped together into the
same class loader. This class loader
is called the Application class loader.
� Depending on the application class
loader policy, this application class
loader can be shared by multiple
applications (EARs), or be unique for
each application, which is the default.
IBM Value Assessment
© Copyright IBM Corporation 2007
29
WebSphere ClassLoader policies cont.
� There are settings in WAS that allow you to influence WebSphere class loader behavior.
– When the application class loader policy is set to Single, a single application class
loader is used to load all EJBs, utility JARs, and shared libraries within the application
server (JVM). If the WAR class loader policy then has been set to Application, the Web
module contents for this particular application are also loaded by this single class loader.
– When the application class loading policy is set to Multiple, the default, each application
will receive its own class loader for loading EJBs, utility JARs, and shared libraries.
Depending on whether the WAR class loader loading policy is set to Module or
Application, the Web module might or might not receive its own class loader.
Module
MultipleSingle
Module
Application
IBM Value Assessment
© Copyright IBM Corporation 2007
30
WebSphere ClassLoader delegation
� WebSphere’s application class loader and WAR class loader both have a setting
called the class loader mode.
� There are two possible values for the class loader mode: PARENT_FIRST and
PARENT_LAST
� PARENT_FIRST. This mode causes the class loader to first delegate the loading
of classes to its parent class loader before attempting to load the class from its
local class path. This is the default policy for standard Java class loaders.
� PARENT_LAST, the class loader attempts to load classes from its local class
path before delegating the class loading to its parent. This policy allows an
application class loader to override and provide its own version of a class that
exists in the parent class loader.
IBM Value Assessment
© Copyright IBM Corporation 2007
31
JNDI
� WebSphere Application Server provides a JNDI implementation that you can use to access CosNaming name servers through the JNDI interface
� CosNaming provides the server-side implementation and is where the name space is stored.
� JNDI essentially provides a client-side wrapper of the name space stored in CosNaming, and interacts with the CosNaming server on behalf of the client.
� WebSphere application clients use the naming service to obtain references to objects related to those applications, such as EJB homes.
� These objects are bound into a mostly hierarchical structure, referred to as a name space.
� In this structure, all non-leaf objects are called contexts.
IBM Value Assessment
© Copyright IBM Corporation 2007
32
JNDI
� Naming operations, such as lookups and binds, are performed on contexts.
� All naming operations begin with obtaining an initial context. You can view the initial context as a starting point in the name space. For example:
– The name myApp/myEJB consists of one non-leaf binding with the name myApp,
which is a context.
– The name also includes one leaf binding with the name myEJB, relative to myApp.
The object bound with the name myEJB in this example happens to be an EJB home
reference.
– The whole name myApp/myEJB is relative to the initial context, which can be viewed
as a starting place when performing naming operations.
IBM Value Assessment
© Copyright IBM Corporation 2007
33
JNDI
� The name space can be accessed and manipulated through a name server.
� Users of a name server are referred to as naming clients
� Naming clients typically use Java Naming and Directory Interface (JNDI) to
perform naming operations. Naming clients can also use the Common Object Request Broker Architecture (CORBA) CosNaming interface.
� Notice that all WebSphere
Application Server processes host their own naming service and local
name space (remove bottleneck)
IBM Value Assessment
© Copyright IBM Corporation 2007
34
JNDI
� There are three options available for binding EJB (<ejb-ref>) and resource
(<resource-ref>) object names to the WebSphere Application Server name
space:
– Simple name -- ejb/webbank/Account
– Compound/fully qualified name -- cell/nodes/node1/servers/server1/ejb/webbank/Account
– Corbaname -- corbaname::myhost1:9812/NameServiceServerRoot#ejb/webbank/Account
� The binding you can use to look up an object depends on whether or not the
application is running within the same application server.
IBM Value Assessment
© Copyright IBM Corporation 2007
35
JNDI - Federated namespace
� The system partition is a reflection of the cell topology and is read-only. This part of the name
space cannot be changed programmatically, because it is based on the configuration rather
than runtime settings.
� The persistent partitions are primarily for the
storage of resource configuration, such as data
sources, JMS destinations etc.
� Cell persistent root. This partition is used
to register persistent objects that are
available to all the nodes and managed
processes of a cell.
� Node persistent root. This partition is
used to register persistent objects available
to the nodes and it their managed
processes.
� The server root transient partition is updateable through APIs, and is meant for
information such as EJB bindings and JNDI names. This name space is
transient and bindings are created each time a server process starts. It reads
configuration data from the file system, for example EJB deployment
descriptors, to register the necessary objects in this space.
IBM Value Assessment
© Copyright IBM Corporation 2007
36
JDBC Resource
� A data source represents a real-world data source, such as a relational database.
� When a data source object has been registered with a JNDI namingservice, an application can retrieve it from the naming service and use it to make a connection to the data source it represents
� Information about the data source and how to locate it, such as its name, the server on which it resides, its port number, and so on, is stored in the form of properties on the DataSource object. This makes an application more portable because it does not need to hard code a driver name, which often includes the name of a particular vendor
� The connection is usually a pooled connection. That is, once theapplication closes the connection, the connection is returned to a connection pool, rather than being destroyed.
� Data source classes and JDBC drivers are implemented by the datasource vendor.
IBM Value Assessment
© Copyright IBM Corporation 2007
37
JDBC Resource
� The programming model for accessing a data source is as follows:
– 1. An application retrieves a DataSource object from the JNDI naming space.
– 2. After the DataSource object is obtained, the application code calls getConnection()
on the data source to get a Connection object. The connection is obtained from a pool
of connections.
– 3. Once the connection is acquired, the application sends SQL queries or updates to
the database.
– 4. Once the application component is finished with the connection, it calls the close()
method on the connection. Closing a connection handle should not close the physical
connection to the EIS.
IBM Value Assessment
© Copyright IBM Corporation 2007
38
JDBC Resource
� In WebSphere Application Server, connection pooling is provided by two parts, a
JCA Connection Manager and a relational resource adapter
� The JCA Connection Manager provides connection pooling, local transaction,
and security support
� The relational resource adapter provides JDBC wrappers and the JCA CCI
implementation that allows BMP, JDBC applications, and CMP beans to access the database
IBM Value Assessment
© Copyright IBM Corporation 2007
39
JDBC Resource – Connection Pooling
� WebSphere® Application Server provides connection pooling for Java Database
Connectivity (JDBC), Java™ Message Service (JMS), and Enterprise Information
System (EIS) connections.
� The purpose of pooling connections is to improve performance by reducing the
overhead involved in creating a new connection every time the application
requests one.
� For JDBC connections, there is one connection pool for each data source that is created in WebSphere Application Server
IBM Value Assessment
© Copyright IBM Corporation 2007
40
Web Services for J2EE (JAX-RPC and WSEE)
� JAX-RPC provides the programming model for SOAP-based applications by
abstracting the runtime details and providing mapping services between Java
and WSDL.
� Web Services for J2EE Specification (WSEE) adds additional artifacts to those
defined by JAX-RPC and brings JAX-RPC to the J2EE container.
� WSEE defines the required architecture for Web services for the Java 2 Platform
Enterprise Edition (J2EE) environment.
� WSEE standardizes the packaging, deployment, and programming model for
Web services in a J2EE environment.
� Although WSEE does not restrict any implementation, it only defines two:
– Stateless session EJB in an EJB container
– Java class running in a Web container
IBM Value Assessment
© Copyright IBM Corporation 2007
41
JAX-RPC Client
� A JAX-RPC client is capable of invoking a Web service irrespective of whether
the service has been defined on the J2EE platform or on a non-Java platform.
� JAX-RPC clients can run inside a J2EE container or as a stand-alone Java
client.
� There are three types of Web services clients:
– Static stub
– Dynamic proxy
– Dynamic invocation interface (DII)
IBM Value Assessment
© Copyright IBM Corporation 2007
42
JAX-RPC Client – Static Stub
� After the proxy classes have been generated, they are copied to the client
machine. The client can then invoke the Web service based only on these proxy
classes.
� These proxy classes are generated from the WSDL of the Web service.
– In WebSphere Application Server, the proxy classes can be generated by the tool
<WAS_HOME>/bin/WSDL2JAVA.
IBM Value Assessment
© Copyright IBM Corporation 2007
43
JAX-RPC Client – Static Stub, calling sequence
1. The client instantiates the service locator.
2. The client calls the service locator to retrieve the SEI (an instance of the
client stub that implements the SEI is returned).
3. The client invokes a Web service through the SEI.
IBM Value Assessment
© Copyright IBM Corporation 2007
44
WSEE Client – Static Stub, calling sequence
1. The client makes an JNDI lookup to get an instance of the service object,which implements a service interface.
2. The client uses a factory method of the service object to retrieve the client
stub. The client stub implements the SEI.
3. The client invokes the Web service through the SEI.
The configurations for the Web service client and server side are represented by
the client and server deployment descriptor shown at the bottom
IBM Value Assessment
© Copyright IBM Corporation 2007
45
JAX-RPC Client – Dynamic Proxy and DII
� Dynamic Proxy
� In dynamic proxy clients, the default destination of the Web service can be changed in the client by specifying a different destination in the client application.
� At runtime the service locator is instantiated. The SEI is retrieved using a
destination (QName).
� Dynamic invocation interface (DII) - (limited support in WAS)
� DII is used when the WSDL of the Web service can change considerably over
time. DII-based clients do not use proxy classes, but instead they read the entire
WSDL file during runtime:
– Instantiate a DII service class.
– Instantiate a Call object (Call is a class provided by JAX-RPC).
– Populate the Call object.
– Invoke the Web service operation on the Call object.
IBM Value Assessment
© Copyright IBM Corporation 2007
46
WSEE Server Container responsability
� A server container provides a JAX-RPC runtime environment for invoking Web
services ports. The container is responsible for:
– Listening to Web services SOAP HTTP requests
– Parsing the inbound message
– Mapping the messages to the implementation class and method
– Creating Java objects from the SOAP envelope
– Invoking the service implementation bean handlers and instance methods
– Capturing the response
– Mapping the Java response objects into a SOAP message
– Creating the message envelope
– Sending the message to the client
IBM Value Assessment
© Copyright IBM Corporation 2007
47
SOAP over HTTP request
� The client request to the Java proxy is handled by the SOAP client and is routed
to the server over HTTP.
� In the server, the WebSphere SOAP engine calls a JavaBean Web service as a
servlet, or uses a servlet in a Web router module to invoke an EJB Web service.
IBM Value Assessment
© Copyright IBM Corporation 2007
48
References
� http://www.redbooks.ibm.com
IBM Italia SpA
© 2007 IBM Corporation
Thank' you
Marco Dragoni