IBM WebSphere survey

pityingmushroomInternet και Εφαρμογές Web

7 Αυγ 2012 (πριν από 5 χρόνια και 10 μέρες)

288 εμφανίσεις

IBM WebSphere survey

Kristian Bisgaard Lassen

University of Aarhus

IBM WebSphere survey

2

Tools


WebSphere


Application Server


Portal


Studio


Business Integration Server

University of Aarhus

IBM WebSphere survey

3

BPEL4WS (abbr. BPEL)


Business Process Execution
Language for Web Services (OASIS
specification)


XML syntax and typed by XML
Schema


Mapped to EJB components

University of Aarhus

IBM WebSphere survey

4

Example of BPEL

University of Aarhus

IBM WebSphere survey

5

Modeling features


Sequencing (dashed arrow)


Concurrency (free grouping)


Synchronization (solid arrow)


Hierarchy (sub process)


Reuse (instances)

University of Aarhus

IBM WebSphere survey

6

WSDL description


Web Service Definition Language


Port type


Describes the operations the process
supports


Operation


Defined by input and output messages


Both does not need to be defined


Similar to a function declaration

University of Aarhus

IBM WebSphere survey

7

BPEL general


Describes processes by what
activities they perform and which
processes they interact with


Visualization of a BPEL process can
be done in several ways in contrast
to e.g. state charts

University of Aarhus

IBM WebSphere survey

8

Basic activity content (1)


Name


Join condition


Default expression is a logic OR of link
status of incoming links


Can be defined as any Boolean
expression


Suppress join failure (yes | no)

University of Aarhus

IBM WebSphere survey

9

Basic activity content (2)


Source links


Optional transition condition


Target links

University of Aarhus

IBM WebSphere survey

10

Basic activity content (3)


All activities can have event
handlers


Event handlers are invoked
concurrently with the activity


Semantics of event handlers are
similar to that of the Pick activity

University of Aarhus

IBM WebSphere survey

11

BPEL process activities (1)


Receive


Blocking wait for a message


Reply


Constructs a message to a message
received in a Receive activity

University of Aarhus

IBM WebSphere survey

12

BPEL process activities (2)


Invoke


Allows a process to invoke a one
-
way
operation on a port type offered by a
partner


Possible to specify


Exception handlers


Compensation handlers

University of Aarhus

IBM WebSphere survey

13

BPEL process activities (3)


Assign


Update variables with data


Throw


Generate a named exception


Wait


Makes the process wait for a certain
period of time

University of Aarhus

IBM WebSphere survey

14

BPEL process activities (4)


Empty


No operation


Useful for


Synchronization


Suppressing exceptions


Sequence


Perform activities sequentially


Switch


Allows conditional branching

University of Aarhus

IBM WebSphere survey

15

BPEL process activities (5)


While


Perform a certain activity until a
condition is meet


Pick


Blocking activity waiting for a message
or an ‘alarm’ to go off


Flow


Construct allows one or more activity
to be performed concurrently

University of Aarhus

IBM WebSphere survey

16

BPEL process activities (6)


Scope


A nested activity


Compensate


Fault handler for scoped activities

University of Aarhus

IBM WebSphere survey

17

Process lifecycle


BPEL4WS processes are long
running stateful interactions


Process instantiation is implicit


Termination can happen if


The activity completes normally


A fault is reached in the process scope


Explicit termination

University of Aarhus

IBM WebSphere survey

18

Partner links (1)


The type characterizes relationship
between two services by roles (e.g.
buyer and seller)


A role specifies a WSDL port type


Partner link is an instantiation of a
partner link type


Partners can be selected both
statically and dynamically through
assignment (Assign)

University of Aarhus

IBM WebSphere survey

19

Partner links (2)


Business partner


A subset of a partner link type


Endpoint reference


Dynamical reference of port. Used
typically when a certain instance of a
service is needed

University of Aarhus

IBM WebSphere survey

20

Business Process Choreographer


BPEL processes can be contained in
BPC


BPC add to BPEL staff activities


Activities which requires human
interaction

University of Aarhus

IBM WebSphere survey

21

Staff activity


When a staff activity is invoked work
items are generated


A role can have three roles


Potential owner


Can claim the activity, complete it or transfer
it to another potential owner


Editor


Can add information to the work item but not
complete it


Reader


Can only check the work item status

University of Aarhus

IBM WebSphere survey

22

BPEL+


WebSphere specific


Integrated with Java, e.g. in


Variable type declarations


Transition conditionals


In Invoke constructs

University of Aarhus

IBM WebSphere survey

23

WebSphere Studio (1)


University of Aarhus

IBM WebSphere survey

24

WebSphere Studio (2)


University of Aarhus

IBM WebSphere survey

25

WebSphere Studio (3)

University of Aarhus

IBM WebSphere survey

26

Future work


Develop a running example of
something in WebSphere Studio


Port the Bankdata model to BPEL or
BPEL+ in WebSphere Studio


Compare BPEL to the Eindhoven
business flow model


Investigate ways to restrict CPN
models so they can translate to
BPEL