A08 WAF - Web Application Framework

Transcription

1 A08 WAF - Web Application Framework Dejan Mihajlovic, Seniour Consultant Michael Schramm, IT Specialist dejan_mihajlovic@at.ibm.com michael_schramm@at.ibm.com

2 Contents History of the WAF Goal of the framework Strategical positioning within IBM WebSphere Software Platform Architecture Features Advantages and Trade-offs of WAF WAF as IBM Austria BIS Asset 12/19/2001 IBM Web Application Framework 2

3 Everything began 2 years ago Yellow pages of Austria: Herold Business Data: Common problems, that are not part of customer requirements: How to keep knowledge about logical session (http) How to access back-end systems How to handle browser behaviour (forward, back ) How to control transactional security 12/19/2001 IBM Web Application Framework 3

4 WAF implements behaviour common to all web applications WAF is a techical Java Server Application Framework that implements basic web server concepts Extension to the Web Application Server: Classes for Use Case Logic, Preconditions.. Extended Error-Handling Personalization... 12/19/2001 IBM Web Application Framework 4

5 WAF is one possible implementation of J2EE Architecture WAF is an Application and a Model that should be used as a basis for further Application development through extensions of existing classes WAF should be seen as a component that implements common web functionality 12/19/2001 IBM Web Application Framework 5

6 The Goal of WAF Increase reusability and productivity Very fast development cycles Basis for development of other reusable components (Personalization, Permissions...) WAF pre-defines a software architecture Distribution (Session EJB) DB Independence Multi Channel (HTML, IIOP) 12/19/2001 IBM Web Application Framework 6

7 WebSphere Software Platform Customer and Partner Applications Application Accelerators Foundation Extension Development Presentation Deployment Integration IBM WAF Host Publisher MQSeries Integrator Foundation Extensions Foundation 12/19/2001 IBM Web Application Framework 7

8 WAF as Company Strategic Internet/Intranet platform Application 1 Application 2... Application n W A F Web Application Server (IBM WebSphere,...) 12/19/2001 IBM Web Application Framework 8

9 Rapid Web Application Development (1) WAF implements already a basic concepts - Design Phase will be much shorter WAF has been tested - Testing will be shorter and a new Application will be stable Reusability based on components is possible 12/19/2001 IBM Web Application Framework 9

10 Rapid Web Application Development (2) Clear division of responsibility makes maintenance much easier (change of WAS, change of EJB API,...) Good performance Certain functionality can be parameterised 12/19/2001 IBM Web Application Framework 10

11 WAF Architecture Presentation Layer Servlet JSP / XSL Java App Business Logic Layer Action Java Beans Data Access Layer JDBC Session EJB - Stateful Session EJB - Stateless DB2 ORACLE 12/19/2001 IBM Web Application Framework 11

12 3-Layer Architecture Presentation Layer Servlet API JSP, XSL/XML Java App Clients Business Logic Layer Action (Use Case Implementation) User Session Data Access Layer WebSphere Data Source ResultList (implements JDBC API) no Entity EJBs 12/19/2001 IBM Web Application Framework 12

13 Request Flow within WAF Presentation Layer Business Logic Data Access HTTP Servlet Action ResultList *ML Page ResponseData DataObject DataObject 12/19/2001 IBM Web Application Framework 13

14 WAF Features Presentation Layer (web clients) Presentation Layer (Java application clients) Presentation Layer (general) Business Logic Layer Data Access Layer Utilities Administration Tool 12/19/2001 IBM Web Application Framework 14

15 Presentation Layer Web Clients Servlet base class handle HTTP protocol / Servlet API no business logic trivial implementation of application servlets call business logic (via EJB or locally) handle parallel request problem Dispatching to JSPs (NLS aware) Processing XSL/XML stylesheets 12/19/2001 IBM Web Application Framework 15

16 Presentation Layer Java Clients EJB Manager allow simple access to business logic handle (hide) EJB details work using Access Beans (no EJBs directly) cache InitialContext and homes Developer work with simple JavaBeans 12/19/2001 IBM Web Application Framework 16

17 Presentation Layer General State Machine used when mapping between servlets -> actions -> response page is not simple matrix lookup based on input parameters and session state Request Dispatcher and Response Dispatcher Multi Language Support language information passed through framework automatically forwarding to JSP/XSL of correct language 12/19/2001 IBM Web Application Framework 17

18 Business Logic Layer (1) Action base class handles License Server (FlexLm) Preconditions Permissions system Action base class provides mechanism for including other actions call data access layer handle error case generically 12/19/2001 IBM Web Application Framework 18

19 Business Logic Layer (2) User Session State information, cached data Organized in sub sessions (request status) "Back Button Problem" Timeout mechanism Session/Action statistics in XML format 12/19/2001 IBM Web Application Framework 19

20 Data Access Layer Database Manager JDBC 1.0 connection pooling JDBC 2.0 DataSource (transaction aware) Different strategies for db access Result List Indexed Result List Cached Result List XML Convertable interface 12/19/2001 IBM Web Application Framework 20

21 Code Generator for VisualAge Generation of application classes Business Logic Servlet Actions Preconditions Enumerations Data Access Objects Result Lists DataObjects Keys 12/19/2001 IBM Web Application Framework 21

22 WAF Utilities Logging & Tracing Statistics Scheduler Mail sending National Language Support (NLS) Administration Tool Monitor framework and application Admin actions, like suspend application 12/19/2001 IBM Web Application Framework 22

23 WAF Utilities Logging, Tracing, Statistics Daily XML files Logging versus Tracing Session Statistics Timestamp, User ID, Session ID, etc. Application specific data Action Statistics Once Per Request/Response Input Parameters and Output Objects 12/19/2001 IBM Web Application Framework 23

24 WAF Utilities Scheduler Periodic Tasks Objects can register to be called periodically / asynchronously WAF tasks Application tasks Timeout Handling Backups 12/19/2001 IBM Web Application Framework 24

25 WAF Utilities Mail sending Java Mail API & Activation Framework Configuration in XML file Simple call from application 12/19/2001 IBM Web Application Framework 25

26 WAF Utilities National Language Support Current user language known in GUI and business logic Standard servlets to change language Automatic forwarding to JSPs/XSLs of correct language Strings created in business logic held in properties files 12/19/2001 IBM Web Application Framework 26

27 WAF Utilities Error Handling Error/Exception handling exception hierarchy for runtime problems error beans (XML convertable) JSP, XSL traces, statistics mapped to resource bundles 12/19/2001 IBM Web Application Framework 27

28 WAF Utilities Miscellaneous Enumeration classes Framework Initializer Application Initializer System Parameters Request Killer parallel request problematic early abort of requests in BLL or DAL RMI Connection Helper 12/19/2001 IBM Web Application Framework 28

29 WAF Utilities Administration Tool Monitor application and framework status user session statistics database pooling details memory usage, reference counting Administrative tasks temporary locking of application (re)initializing / shutting down application killing user sessions killing database connections 12/19/2001 IBM Web Application Framework 29

30 Summary Advantages using WAF (1) Platform Platform independence Web- and Application Server independence EJBs Benefits without knowledge New EJB API without changing application Servlets Benefits without knowledge New Servlet API without changing application 12/19/2001 IBM Web Application Framework 30

31 Summary Advantages using WAF (2) Focus on application Most technical topics already implemented, tested and proved Developers start implementing business logic on day 1 Use of EJBs can be configured depending on system requirements 12/19/2001 IBM Web Application Framework 31

32 Summary Trade-offs Security features of EJBs cannot be used (Standard EJB API won't be enough for many customers anyway) No use of entity beans (for performance and simplicity reasons) Evaluation of performance using complex data: JDBC vs. EJB entity CMP bean (1:10) 12/19/2001 IBM Web Application Framework 32

33 WAF - IBM Austria Asset (1) Application in IBM ICM Implemented in 5 reference projects Herold Business Data Yellow pages of Austria ( Uniqa Insurance CallDirect ( Paradine AG eptos (Inbound Supply Chain Mgmt) IBM HR Intranet Application RZB Bank e-custody ( 12/19/2001 IBM Web Application Framework 33

34 WAF - IBM Austria Asset (2) Full Documentation Architectural Templates Work Product Programmers Guide Rational Rose Model class diagrams sequence diagrams JavaDocs Sample Application Code Generator for VisualAge 12/19/2001 IBM Web Application Framework 34

35 Further Information Web Pages WAF: WebSphere: VisualAge: Mail Contact 12/19/2001 IBM Web Application Framework 35

36 Questions & Answers Please do not forget to fill out the evaluation forms 12/19/2001 IBM Web Application Framework 36