Java 2 Enterprise Edition SSH Frameworks

1
Java 2 Enterprise Edition SSH Frameworks

• Presenter Lee, Gun
• 2007-02-05 Updated

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Agenda
3
Process for running JSP
JSP File
Request
Web Browser
Servlet Source Code
Response
Compiled Servlet Class
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MVC Introduction

• The Model-View-Controller (MVC) is a commonly
  used and powerful architecture for GUIs.
• The MVC paradigm is a way of breaking an
  application, or even just a piece of an
  application's interface, into three parts the
  model, the view, and the controller. MVC was
  originally developed to map the traditional
  input, processing, output roles into the GUI
  realm.

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Simple Model
Request
Modify Data
Web Brower
JSP
Database
Response
Read Data
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Model 1 Architecture
Application Server (EJB Server)
Application Server Database
JSP
Request
Web Browser
Response
Database
JavaBeans
Web Server
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Model 2 Architecture
Application Server (EJB Server)
Application Server Database
Servlet (Controller)
Request
Web Browser
Database
JSP (View)
JavaBeans (Model)
Response
Web Server
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Struts Introduction

• The goal of the Apache Struts project is to
  encourage application architectures based on the
  "Model 2" approach, a variation of the classic
  Model-View-Controller (MVC) design paradigm.
  Under Model 2, a servlet (or equivalent) manages
  business logic execution, and presentation logic
  resides mainly in server pages.

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Struts for MVC Model
web.xml
Struts-config.xml
Action Servlet (Controller)
Web Browser
Java Bean EJB (Model)
Action (Business Logic)
Web Server
Action Form (Java Bean Or EJB)
Other Action
JSP (View)
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Several models in Struts

• Model 1
• JSP / Servlet
• JSP Java Bean
• JSP Custom Tag
• Integrate above 3 models
• Model 2
• JSP / Servlet Struts
• JSP Struts JSTL JSF
• JSP Struts Velocity Sitemesh
• Integrate above 3 models

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Configuration in web.xml

• ltservletgt
• ltservlet-namegtactionlt/servlet-namegt
• ltservlet-classgtorg.apache.struts.action.Action
  Servletlt/servlet-classgt
• ltinit-paramgt
• ltparam-namegtconfiglt/param-namegt
• ltparam-valuegt/WEB-INF/config/struts-config.x
  mllt/param-valuegt
• lt/init-paramgt
• lt/servletgt
• ltservlet-mappinggt
• ltservlet-namegtactionlt/servlet-namegt
• lturl-patterngt.dolt/url-patterngt
• lt/servlet-mappinggt

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Action Form in Struts

• An ActionForm is a JavaBean that extends
  org.apache.struts.action.ActionForm.
• ActionForm maintains the session state for web
  application and the ActionForm object is
  automatically populated on the server side with
  data entered from a form on the client side.

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Example of Action Form

• public class Message
• private String text
• private Message nextMessage
• public String getText() return text
• public void setText(String text)
• this.text text
• public Message getNextMessage()
• return nextMessage
• public void setNextMessage(Message
  nextMessage)
• this.nextMessage nextMessage

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Action in Struts

• The Action Class is part of the Model and is a
  wrapper around the business logic.
• The purpose of Action Class is to translate the
  HttpServletRequest to the business logic.
• To use the Action, we need to  Subclass and
  overwrite the execute() method.
• In the Action Class all the database/business
  processing are done.
• It is advisable to perform all the database
  related stuffs in the Action Class.

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Action in Struts (Cont.)

• The ActionServlet (commad) passes the
  parameterized class to Action Form using the
  execute() method.
• The return type of the execute method is
  ActionForward which is used by the Struts
  Framework to forward the request to the file as
  per the value of the returned ActionForward
  object.

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Example of Action

• public class SymposiumAction extends
  DispatchAction
• private SymposiumService symposiumService
  null
• public void setSymposiumService(SymposiumService
  symposiumService)
• this.symposiumService symposiumService
• public ActionForward list(ActionMapping mapping,
  ActionForm form,
• HttpServletRequest request, HttpServletResponse
  response)
• throws Exception
• request.setAttribute("symposiumList",
  symposiumService.findSymposiumList())
• return mapping.findForward("list")

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DAO (Data Access Object) in Struts

• Access to data varies depending on the source of
  the data.
• Access to persistent storage, such as to a
  database, varies greatly depending on the type of
  storage (relational databases, object-oriented
  databases, flat files, and so forth) and the
  vendor implementation.
• We will implement DAO in hibernate persistence
  Layer.

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Tag Libraries in Struts

• HTML Tag Lib
• The tags in the Struts HTML library form a bridge
  between a JSP view and the other components of a
  Web application.
• Bean Tag Lib
• Contains JSP custom tags useful in defining new
  beans (in any desired scope) from a variety of
  possible sources, as well as a tag to render a
  particular bean (or bean property) to the output
  response.
• Logic Tag Lib
• Contains tags that are useful in managing
  conditional generation of output text, looping
  over object collections for repetitive generation
  of output text, and application flow management

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Tag Libraries in Struts (Cont.)

• Nested Tag Lib
• Nested tags supporting classes extend the base
  struts tags to allow them to relate to each other
  in a nested nature.
• Tiles Tag Lib
• Tiles builds on the "include" feature provided by
  the JavaServer Pages specification to provide a
  full-featured, robust framework for assembling
  presentation pages from component parts.

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Sample of Struts Tag Library

• lt_at_ taglib uri"http//jakarta.apache.org/struts/t
  ags-bean" prefix"bean"gt
• lt_at_ taglib uri"http//jakarta.apache.org/struts/t
  ags-html" prefix"html"gt
• lt_at_ taglib uri"http//jakarta.apache.org/struts/t
  ags-logic" prefix"logic" gt
• ltlogiciterate name"books" type"org.library.bean
  .Book" id"book"gt
• lttrgt
• lt-- book informations --gt
• lttdgt ltbeanwrite name"book" property"author"
  /gt lt/tdgt
• lt/tdgt
• lt/logiciterategt

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Configuration in struts-config.xml

• ltstruts-configgt
• ltdata-sources /gt
• ltform-beans/gt
• ltglobal-exceptions /gt
• ltglobal-forwards/gt
• lt!-- Action Mappings --gt
• ltaction-mappingsgt
• ltaction forward"/WEB-INF/jsp/index.jsp"
  path"/default" /gt
• lt/action-mappingsgt
• lt!-- Message Resources Configuration --gt
• ltmessage-resources parameter"org.research.strut
  s.ApplicationResources" /gt
• lt/struts-configgt

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What is Hibernate?

• Hibernate is a powerful, high performance
  object/relational persistence and query service.
• Hibernate lets you develop persistent classes
  following object-oriented idiom - including
  association, inheritance, polymorphism,
  composition, and collections.

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What does Hibernate do?

• OO based model
• Query language similar to SQL
• Transparent Write-behind
• Advanced Cache Strategy
• Optimized SQL
• Fine grained object mapping
• Vendor Abstraction and Independence
• Improves performance by caching, lazy loading and
  etc

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Hibernate Architecture
Transient Objects
Business Layer
Persistence Objects
Persistence Layer
Session Factory
Session
Transaction
Transaction Factory
Connection Provider
JNDI
JDBC
JTA
Hibernate API
J2EE API
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Mechanism for Hibernate

• Read the hbm.xml during the runtime
• Read the class which was included in hbm.xml
• Auto Create SQL after read the stuff on the above
• Create proxy class dynamically using the CGLIB,
  and then put SQL in it

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Mechanism for Hibernate (Cont.)

• Call the session object, when user access
  persistency objects
• save(Object aPersistentObject)
• delete(Object aPersistentObject)
• update(Object aPersistentObject)
• Each call retrieve to SQL via proxy class, and
  send to RDB.

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A sample for Persistent class

• public class Message
• private String text
• private Message nextMessage
• public String getText() return text
• public void setText(String text)
• this.text text
• public Message getNextMessage()
• return nextMessage
• public void setNextMessage(Message
  nextMessage)
• this.nextMessage nextMessage

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A simple Hibernate XML mapping

• lt?xml version"1.0"?gt
• lt!DOCTYPE hibernate-mapping PUBLIC
  "-//Hibernate/Hibernate Mapping DTD//EN"
• "http//hibernate.sourceforge.net/hibernate-mappin
  g-2.0.dtd"gt
• lthibernate-mappinggt
• ltclassname"hello.Message"table"MESSAGES"gt
• ltproperty name"text" column"MESSA
  GE_TEXT"/gt
• ltmany-to-one name"nextMessage"
  cascade"all"
• column"NEXT_MESSAGE_ID"/gt
• lt/classgt
• lt/hibernate-mappinggt

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A sample for Hibernate DAO Interface

• package org.research.symposium.dao
• import java.util.List
• import org.research.symposium.model.ResearchDepart
  ment
• public interface ResearchDepartmentDAO
• public void save(ResearchDepartment
  transientInstance)
• public void delete(ResearchDepartment
  persistentInstance)
• public ResearchDepartment findById(java.lang.Inte
  ger id)
• public List findByExample(ResearchDepartment
  instance)

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A sample for Hibernate DAO

• public void delete(ResearchDepartment
  persistentInstance)
• log.debug("deleting ResearchDepartment
  instance")
• try
• getHibernateTemplate().delete(persistentI
  nstance)
• log.debug("delete successful")
• catch (RuntimeException re)
• log.error("delete failed", re)
• throw re

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The benefits of Spring

• Spring can effectively organize your middle tier
  objects, whether or not you choose to use EJB.
• Spring can eliminate the proliferation of
  Singletons seen on many projects.
• Applications built using Spring are very easy to
  unit test.

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The benefits of Spring (Cont.)

• Spring helps you solve many problems without
  using EJB.
• Spring provides a consistent framework for data
  access, whether using JDBC or an O/R mapping
  product such as Hibernate or a JDO implementation.

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Summery of Spring Framework
Spring AOP Aspect Oriented Programming
Spring ORM Hibernate Support JDO Support
Spring Web Web Application Context
Spring Web MVC Web MVC Framework Web Views JSP /
Velocity PDF / Excel
Spring DAO JDBC Support DAO Support
Spring Context UI Support Validation EJB Support
Spring Core Supporting Utilities Bean Container
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What is IoC?

• IoC is short of Inversion of Control.

Interface Finder
Lister
finder
finderByID
listByID
ltimplementsgt
FinderWithConstruct
ltltcreategtgt
listObjectName
FinderWithConstruct finderByID
private Finder finder new FinderWithConstruct()
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What is AOP?
Check Point
Injector
Combination of Aspect
Separation of Aspect
Security
Logging
Tran Mgmt
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Spring Middle Tiles
Web fronted using Struts or WebWork
Spring WEB
Spring AOP
Spring ORM
Transaction Management Using Spring decl. trans
Hibernate Mappings Custom Hibernate DAOs
Spring Core
Spring DAO
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SSH Architecture
Spring Container
Servlet Container
Struts Framework
UI (User Interface) Layer
Spring Framework
Business Layer
Hibernate Framework
Persistence Layer
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SSH Framework - Struts
Spring
Struts-config.xml
Hibernate
web.xml
Action Servlet (Controller)
Web Browser
Action (Business Logic)
Web Server
Action Form (Java Bean Or EJB)
Other Action
JSP (View)
S
S
H
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SSH Framework - Spring
Hibernate
Struts
Action (Business Logic)
ServiceImpl
Web Browser
Action Form (Java Bean Or EJB)
AbstractService
Other Action
ApplicationContext.xml
S
S
H
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SSH Framework - Hibernate
Struts
Spring
DAOImpl
ModelImpl
Web Browser
AbstractDAO
AbstractModel
XXX.hbm.xml
S
S
H
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Spring integration with Struts

• Use Spring's ActionSupport
• Override the RequestProcessor
• Delegate action management to Spring
• A much better solution is to delegate Struts
  action management to the Spring framework.
• You can do this by registering a proxy in the
  struts-config action mapping.
• The proxy is responsible for looking up the
  Struts action in the Spring context.
• Because the action is under Spring's control, it
  populates the action's JavaBean properties and
  leaves the door open to applying features such as
  Spring's AOP interceptors.

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Spring integration with Struts (Cont.)

• Delegation method of Spring integration
• ltaction path"/searchSubmit"
  type"org.springframework.web.struts.DelegatingAct
  ionProxy"
• input"/searchEntry.do"
• name"searchForm"gt
• lt/actiongt
• ltplug-in className"org.springframework.web.struts
  .ContextLoaderPlugIn"gt ltset-property
  property"contextConfigLocation"
  value"/WEB-INF/beans.xml"/gt
• lt/plug-ingt

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Spring integration with Struts (Cont.)

• Register a Struts action in the Spring context
• ltbeansgt
• ltbean name"/searchSubmit"
• class"ca.nexcel.books.actions.SearchSubmi
  t"gt
• ltproperty name"bookService"gt
• ltref bean"bookService"/gt
• lt/propertygt
• lt/beangt
• lt/beansgt

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Spring integration with Hibernate

• Two approaches
• Inversion of Control with a HibernateTemplate and
  Callback.
• Extending HibernateDaoSupport and Applying an AOP
  Interceptor.
• Configure the Hibernate SessionFactory
• Extend your DAO Implementation from
  HibernateDaoSupport
• Wire in Transaction Support with AOP

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Spring integration with Hibernate (Cont.)

• Configuring the Hibernate SessionFactory in
  Spring
• ltbean id"sessionFactory" class"org.springframewo
  rk.orm.hibernate3.LocalSessionFactoryBean"gt
• ltproperty name"mappingResources"gt
• ltlistgt ltvaluegtcom/zabada/springrecipes/base/Widget
  .hbm.xml
• lt/valuegt
• lt/listgt
• lt/propertygt
• lt/beangt

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Spring integration with Hibernate (Cont.)

• Extending HibernateDaoSupport for the Actual DAO
  Implementation.
• public class WidgetDAOHibernateImpl
• extends HibernateDaoSupport
• implements WidgetDAO
• public Collection getWidgets()
• return getHibernateTemplate().loadAll(Widget.c
  lass)
• public Widget saveWidget(Widget widget)
• getHibernateTemplate().saveOrUpdate(widget)
• return widget

47
Spring integration with Hibernate (Cont.)

• Using AOP to Wire Up the DAO and Transaction
  Management
• ltbean id"hibernateInterceptor"
• class"org.springframework.orm.hibernate3.Hibernat
  eInterceptor"gt
• ltproperty name"sessionFactory"gt
• ltref bean"sessionFactory"/gt
• lt/propertygt
• lt/beangt
• ltbean id"widgetDaoTarget"
• class"com.zabada.springrecipes.hibernate.WidgetDA
  OHibernateImpl"gt
• ltproperty name"sessionFactory"gt
• ltref bean"sessionFactory"/gt
• lt/propertygtlt/beangt

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Spring integration with Hibernate (Cont.)

• ltbean id"widgetDAO"
• class"org.springframework.aop.framework.ProxyFact
  oryBean"gt
• ltproperty name"proxyInterfaces"gt
• ltvaluegtcom.zabada.springrecipes.base.WidgetDAOlt/va
  luegt
• lt/propertygt
• ltproperty name"interceptorNames"gt
• ltlistgt
• ltvaluegthibernateInterceptorlt/valuegt
• ltvaluegtwidgetDaoTargetlt/valuegt
• lt/listgt
• lt/propertygt
• lt/beangt

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The Packaging for the Whole Project

• WebRoot
• WEB-INF
• Classes
• Config (applicationContext.xml,
  struts-config.xml)
• Jsp (JSP Files)
• Lib (Struts, Spring, Hibernate Libs)
• Tld (Tlds for JSTL or struts)
• Validator (validator-rules.xml validation.xml)
• META-INF
• MANIFEST.MF

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Issues of System.out.println ()

• Output format for logging info isnt so flexible.
• Programmer has to recompile the source if there
  has some changes.
• The efficiency of application can be decrease if
  there are so many println()

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Loggers Level

• Off The OFF Level has the highest possible rank
  and is intended to turn off logging.
• Fatal The FATAL level designates very severe
  error events that will presumably lead the
  application to abort.
• Error The ERROR level designates error events
  that might still allow the application to
  continue running.
• Warn The WARN level designates potentially
  harmful situations.
• Info The INFO level designates informational
  messages that highlight the progress of the
  application at coarse-grained level.
• Debug The DEBUG Level designates fine-grained
  informational events that are most useful to
  debug an application.
• All The ALL Level has the lowest possible rank
  and is intended to turn on all logging.

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Solutions for managing Log4j

• User can enable, disable and switch the logging
  level between (INFO, WARN, DEBUG, ERROR, FATAL,
  OFF, ALL) the various levels at run-time in my
  web application.

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Log4j.xml Configuration

• lt?xml version"1.0" encoding"UTF-8" ?gt
• lt!DOCTYPE log4jconfiguration SYSTEM "log4j.dtd"gt
• ltlog4jconfiguration xmlnslog4j"http//jakarta.a
  pache.org/log4j/"gt
• ltappender name"CONSOLE" class"org.apache.log
  4j.ConsoleAppender"gt
• ltlayout class"org.apache.log4j.PatternLay
  out"gt
• ltparam name"ConversionPattern"
  value"p - C1.M(L) mn"/gt
• lt/layoutgt
• lt/appendergt
• ltlogger name"org.springframework"gt
• ltlevel value"WARN"/gt
• lt/loggergt
• ltlogger name"com.nanumsem"gt
• ltlevel value"DEBUG"/gt
• lt/loggergt
• ltrootgt
• ltlevel value"WARN"/gt

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Log4j DEMO

• protected final Log logger LogFactory.getLog(get
  Class())
• if (logger.isDebugEnabled())
• logger.debug("entering 'list' method...")

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P6SPY

• P6Log intercepts and logs the database statements
  of any application that uses JDBC.
• This application is particularly useful for
  developers to monitor the SQL statements produced
  by EJB servers Or ORM.
• P6Spy is designed to be installed in minutes and
  requires no code changes.

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Integrate P6SPY With Hibernate

• ltbean id"dataSource"
• class"org.apache.commons.dbcp.BasicDataSource"gt
• ltproperty name"driverClassName"gt
• ltvaluegtcom.p6spy.engine.spy.P6SpyDriverlt/valuegt
  
• lt/propertygt
• ltproperty name"url"gt
• ltvaluegtjdbcmysql//localhost3306/lt/v
  aluegt
• lt/propertygt
• ltproperty name"username"gt
• ltvaluegtusernamelt/valuegt
• lt/propertygt
• ltproperty name"password"gt
• ltvaluegtpasswordlt/valuegt
• lt/propertygt
• lt/beangt

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SQL Profiler DEMO
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Reference

• http//www.java.com
• http//struts.apache.org/
• http//sourceforge.net/
• http//db.apache.org/ojb/
• http//logging.apache.org/log4j/
• http//jakarta.apache.org/velocity/
• http//jakarta.apache.org/commons/
• http//www.hibernate.org/
• http//www.springframework.org/
• http//www.p6spy.com/

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Thank You !