蔡 文 能
交通大學資訊工程學系 tsaiwn@csie.nctu.edu.tw
1

• Java 2 Enterprise Edition
• There are 3 different specifications within the Java framework (J2SE, J2ME, J2EE)
• Created to provide a simple, unified standard for distributed applications through a component based application model
• Specification is managed by a consortium of industry leaders
2

• http://java.sun.com
• http://java.sun.com/j2ee
• http://java.sun.com/j2ee/tutorial/index.html
3

J2EE and Other Java 2 Platform Editions
Source: Computer , August 2000
J2EE, J2SE, J2ME 4

J2EE and Other Java 2 Platform Editions
J2EE, J2SE, J2ME
Source: Sun Microsystems, Inc.
5

Java Development and Runtime Environment
Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE 6

Java 2 Platform Runtime Architecture
Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE
7

Java 2 Platform, Standard Edition (J2SE 1.3)
Source: Sun Microsystems, Inc., http://java.sun.com/j2se/1.3/ 8

Java 2 Platform, Standard Edition (J2SE 1.4)
Source: Sun Microsystems, Inc., http://java.sun.com/j2se/1.4/
9

• A stand alone program
• Client/Server
– BBS, News, FTP, Telnet, …
• Traditional (non-component) N-Tier Systems
– 3-tier application: Browser – WEB Server – DBMS
• New trend:
– Component N-Tier Systems
(J2EE Architecture)
See figures on next slides
10

• Client Tier – Presentation, Business Logic
• Data Tier – Database Management Services
Source: Sun Microsystems, Inc., JDBC 3.0 Specification 11

Traditional(non-component) N-Tier Systems
• Client Tier – Presentation Logic
• Application Tier – Business Logic
• Data Tier – Database Management Services
12
Source: Sun Microsystems, Inc., JDBC 3.0 Specification

Applet
Container
Web Tier Business Tier
EIS Tier
Client Tier
EJB Container
Connector
Enterprise
Information
Services
EJB
Standalone
Client
Web Container
JSP
Servlet
J2EE Server
Machine Client
Machine
Database Server
Machine
13

J2EE Component and Container
Source: Sun Microsystems, Inc., J2EE Specification v1.3
14

• J2EE consists of three major parts:
–
Components
Hold presentation and business logic
–
Containers
Provide context for components
–
Connectors
Provide access to legacy enterprise systems
15

• Application clients
• Applets
• Web components
– Servelets, Java Server Pages (JSP)
–
Portlet (see JSR168)
• Business components
– Enterprise Java Beans (EJB)
16

Applet Component
• An applet is a program written in the JavaTM programming language that can be included in an
HTML page, much in the same way an image is included. When you use a Java technologyenabled browser to view a page that contains an applet, the applet's code is transferred to your system and executed by the browser's Java Virtual
Machine (JVM).
• An applet is a small program that is intended not to be run on its own, but rather to be embedded inside another application.
17

• Applets : Java code that runs inside browser
• Advantages:
– Extends functionality on the client side
– More complicated GUIs than w/ HTML or JavaScript
– Computation can be off-loaded from server
– Users don’t have to build, install, and configure
• Disadvantages:
– Download time
– “Sandbox” limits functionality (unless signed)
– Window management by browser
18

Web Component
• Servlets
– A servlet is a program that extends the functionality of a Web server. Servlets receive a request from a client, dynamically generate the response (possibly querying databases to fulfill the request), and then send the response containing an HTML or XML document to the client
• JSP
– The JavaServer Pages (JSP) technology provides an extensible way to generate dynamic content for a Web client. A JSP page is a textbased document that describes how to process a request to create a response
19

Browser
HTTP Request
Servlet Class wasn’t loaded into System
Class Loader
Load Servlet class
Into System
Web
Services
Servlet Class was loaded
Invoker
HTTP Response
Services
20

• Java Servlet is the bridge for user to use Java solution in Web Server.
• Java Servlet has better performance than
CGI(Common Gateway Interface).
• Java Servlet can use session to replace cookie and enhance security.
• J2EE Server maintains the session for Java
Servlets.
21

New JSP Page
JSP was modified
Browser
HTTP Request (.jsp)
Web
Services
HTTP Response
Java
Source
Code
Compiler
Java
Bytecode
Load Servlet class
Into System
Class Loader
JSP isn’t loaded yet.
Invoker jspServices
22

• JSP has all features of Servlet.
• JSP is a HTML like document.
• JSP is designed for Web Page Developer.
• JSP will change to Java Servlet source.
• JSP is ran via Servlet mode.
23

• JSP has 9 objects which developer can use directly without new it.
JSP Object request response pageContext session application out config page exception java class javax.servlet.ServletRequest
javax.servlet.ServletResponse
javax.servlet.jsp. PageContext javax.servlet.http.HttpSession
javax.servlet.ServletContext
javax.servlet.jsp.JspWriter
javax.servlet.ServletConfig
java.lang.Object
java.lang.Throwable
scope request pag page session application page page page page
24

• JSR168
– Java portlet standard
Browser
HTTP
Portal
Server
• WSRP (Web Services for Remote Portlets ）
– Remote portlet communication protocol
– Portals aggregate remote portlets
JSR168 Portlet Container
JSR168
Portlet
WSRP
JSR168
Portlet
25

• Despite almost all databases supporting SQL, database vendors
(Microsoft Access, Oracle etc.) provide proprietary (no standard)
Application Programming Interfaces for sending SQL to the server and receiving results from it!
• Languages such as C/C++ can make use of these proprietary
APIs directly
– High performance
– Can make use of non standard features of the database
– All the database code needs to be rewritten if you change database vendor or product
• JDBC (Java DataBase Connectivity) is a vendor independent
API for accessing relational data from different database vendors in a consistent way
26
CCTM: Course material developed by James King (james.king@londonmet.ac.uk)

• JDBC provides an API that hides the vendor specific APIs by
inserting a driver between the Java application and the database API
• JDBC requires a vendor-specific driver
• The driver converts calls from JDBC API to vendor’s API => performance penalty
• The driver does not provide access to vendor specific functionality
• The same Java application can be used with a different vendor’s database by simply switching JDBC driver and changing one line of Java code.
• JDBC 1.0 is included inside JDK 1.1 or higher in a package java.sql
• JDBC 2.0 and 3.0 require updated drivers and an additional package javax.sql
27
CCTM: Course material developed by James King (james.king@londonmet.ac.uk)

• By default connections to the database commit each update as soon as it is completed.
• If you want to make a set of changes and only commit the aggregate result if nothing goes wrong auto commit needs to be switched off connection.setAutoCommit(false)
You can then use
connection.commit() to apply the changes
connection.rollback() to undo changes since the last commit
• You can switch auto commit back on using connection.setAutoCommit(true)
28
CCTM: Course material developed by James King (james.king@londonmet.ac.uk)

EJB Component
• Enterprise JavaBean (EJB)
– The Enterprise JavaBeans (EJB) architecture is a server-side technology for developing and deploying components containing the business logic of an enterprise application.
– Enterprise JavaBeans components, termed enterprise beans , are scalable, transactional, and multi-user secure.
• EJB is an architecture for component-based transactional distributed computing.
29

• An enterprise bean contains business logic that operates on the enterprise’s data.
• Client access is mediated by a Container.
• There are three kinds of enterprise beans: session beans, entity beans, and messagedriven beans .
30

• Session objects: for a single client, shortlived, …Stateful, Stateless
• Entity objects: object view of data in the database, shared by multiple clients, longlived, …
• Message-driven objects: triggered by a single client message, short-lived, stateless, …
31

• Stateful
– Possess Internal State
– One per client
– Need to handle activation/ passivation
• Stateless
– Do not possess state
– Can be pooled to handle multiple clients
– Do not need to be passivated
32

• Container Manager
Persistence
– Container responsible for database accesses/ controls
– Developer focuses on data use
• Bean Managed
Persistence
– Developer must write code to handle database accesses/ controls
– Used for more specialized data mapping strategies
33

• Provides an object view of data in the underlying database
• Shared across multiple users
• Long-lived
• Survives container crash
34

• Any enterprise bean must define two interfaces and one or two classes
– Remote interface
• defines a bean ’ s external interface
• must extend javax.ejb.EJBObject (which in turn extends java.rmi.Remote)
– Home interface
• The home interface defines a bean ’ s “ life cycle ” methods, eg. create bean, remove bean, find bean, etc.
• must extend javax.ejb.EJBHome which also extends java.rmi.Remote
35

• Bean Class
– The java class that actually implements the bean ’ s external interface, e.g. the bean class provides implementations for the bean ’ s “ business methods ”
– An entity bean must implement the javax.ejb.EntityBean interface, while a session bean must implement the (you guessed it) javax.ejb.SessionBean. Both of these interfaces extend javax.ejb.EnterpriseBean
• Primary Key
– The primary key is a very simple class that provides a pointer into a database; Only entity beans need a primary key. This class must implment java.io.Serializable (so the entity bean can automatically be sent to persistent storage)
36

• A container is provided by the Application Server vendor to provide basic services that are required by J2EE specification.
• An EJB programmer places their code here, and is assured a variety of basic services are available
• This means the developer doesn ’ t have to code these services from scratch
• Specification states which services must be supported but not how
37

• Security
• Transaction management
• Remote Client Connectivity
• Life Cycle Management
• Database Connection Pooling
38

• The following basic services will be supported by all J2EE compliant products
– RMI/RMI-IIOP
– Resource Pooling
– Thread Control
– Presentation Logic
– Persistence
– Messaging
– And more …
IIOP: Internet Inter-ORB Protocol
ORB: Object Request Broker
39

•
Can
’ t use threads
•
Can
’ t use the AWT
•
Can
’ t act as network server
•
Can
’ t use java.io package
•
Can
’ t load native libray
•
Can
’ t use this as an argument or return value
40

• Developing distributed applications in Java
– Application developer is spared from following details
• Transaction management
• State management
• Multi-threading
• Connection pooling
• Write once, run anywhere
• Interoperability with other languages
• Compatible with CORBA protocols
41

Web Containers
• Web Component Containers
– 1. Servlet Containers
• A servlet container provides network services (by which requests and responses are sent), decodes requests, and formats responses. All servlet containers must support HTTP as a protocol for requests and responses, but may also support additional request-response protocols such as HTTPS.
– 2. JSP Containers
• A JSP container provides the same services as a servlet container and an engine that interprets and processes a JSP page into a servlet.
– 3. Web Containers
• A
Web container provides the same services as a JSP container and access to the J2EE service and communication APIs.
42

EJB Containers
• EJB Container
– Enterprise beans are hosted by an
EJB container . In addition to standard container services, an EJB container provides a range of transaction and persistence services and access to the J2EE service and communication APIs.
43

•
Tomcat : Java-based web server + servlet container w/ JSP environment
• Execution modes:
–
Standalone : default mode for Tomcat
–
Out-of-process add-on : web server plugin opens JVM outside web server; plugin and
JVM communicate using IPC mechanism
(TCP/IP sockets and special protocol)
44

• Communication mechanism between
Tomcat and Apache: web server adapter” or named as “connector”
• Implemented as shared library (e.g., mod_jserv.so, mod_jk.so)
• Uses/manages TCP connections
• Uses the AJPV12/AJPV13 communication protocol
45

• Contract between container and Enterprise
Information Systems (EIS)
• Proprietary and under the hood
• Implementation is available with J2EE specification version 1.3 / 1.4
46

• HTTP/HTTPS
• Java Transaction API (JTA)
• Java Database Connection (JDBC)
• Java Message Service (JMS)
• Java Authentication and Authorization Service (JAAS)
• J2EE
Connector Architecture (JCA)
• Others: RMI-IIOP, JavaIDL, JavaMail, JavaBeans
Activation Framework (JAF), Java API for XML Parsing
(JAXP)
IIOP: Internet Inter-ORB Protocol
47

• J2EE application model partitions the work needed to implement a multi-tier service into two parts
– the business and presentation logic (implemented by the application developer)
– the standard system services provided by the J2EE platform.
• The developer can rely on the platform to provide the solutions for the hard systems level problems of developing a middle-tier service.
48

Source: Sun Microsystems, Inc., http://java.sun.com/j2ee/overview2.html
49

• The J2EE application model provides the benefits of Write Once, Run Anywhere™ portability and scalability for multi-tier applications.
• This standard model minimizes the cost of developer training while providing the enterprise with a broad choice of J2EE servers and development tools.
50

• J2EE Product Provider
• Application Component Provider
• Application Assembler
• Deployer
• System Administrator
• Tool Provider
51

• Integration of J2EE servers with Enterprise
Information Systems (EIS)
• EIS vendor-provided resource adaptors
• Resource adaptor-permitting application servers
52

• J2EE Connector
– The J2EE
Connector architecture defines a standard architecture for connecting the J2EE platform to heterogeneous EISs. Examples of EISs include ERP, mainframe transaction processing, database systems, and legacy applications not written in the Java programming language. By defining a a set of scalable, secure, and transactional mechanisms, the J2EE
Connector architecture enables the integration of EISs with application servers and enterprise applications.
53

Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification 54

Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification 55

Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification
56

Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification 57

• Home Interface: methods for creating, removing, and finding bean instances
• Remote Interface: methods callable by the client
• Object Identity
• Metadata Interface: mainly for dynamic invocation
• Handle
58

Source: Sun Microsystems, Inc., Enterprise JavaBeans 2.0
59

Accessing Enterprise Beans from Servlets/JavaServer Pages
Source: Sun Microsystems, Inc., J2EE Specification, v1.3
60

J2EE Deployment
Source: Sun Microsystems, Inc., J2EE Specification, v1.3
61

Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification 62

Overview of Enterprise Applications Integration (EAI)
Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE 63

Overview of Enterprise Applications Integration (EAI)
Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE 64

Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE 65

Enterprise Beans of the Example Design
Source: Sun Microsystems, Inc., The J2EE Tutorial
66

• Servlets and JSP
– Java technology servlets and JavaServer Pages are server components that run in a web server that supports dynamic HTML generation and session management for browser clients.
• EJB
– Enterprise JavaBeans is a server component model that provides protability across application servers and implements automatic services on behalf of the application components.
• JTA
– Java Transaction API provides a transaction demarcation API.
• JTS
– Java transaction Service defines a distributed transaction management service based on the CORBA Object Transaction Service.
67

• JNDI
– Java Naming and Directory Interface provides access to naming and directory services, such as DNS, LDAP, NDS, and CORBA Naming.
• RMI-IIOP
– Remote Method Invocation(RMI) creates remote interfaces for Java-to-
Java communication. This extension uses the CORBA standard IIOP communication protocol.
• Java IDL
– Java Interface Definition Language creates remote interfaces to support java-to-CORBA communications.
68

• JDBC
– JDBC database access API provides uniform access to relational databases.
• JMS
– Java Messaging Service supports asynchronous communication using either a reliable queuing or publish/subscribe model.
• JavaMail
– JavaMail provides a protocol-independent framework to build mail and messaging applications.
• JAF
– JavaBeans Activation Framework provides standard services to determine the type of an arbitrary piece of data and activate an appropriate
JavaBeans component to manipulate the data.
69

• Distributed Objects
– CORBA, DCOM, etc.
– Three-tier scenario: presentation, business logic, and backend databases
• Hard to “ get right ” without the proper infrastructure
• Server-Side Components
– Focuses on encapsulating “ business rules ” into objects in the middle tier
• Component Transaction Monitors
– Descendant of CORBA ’ s Object Request Broker
• provides discovery, persistence, event notification, transactions, etc. for three-tier or n-tier applications
70

• Naming Services
– Provide application clients, EJB and Web components with access to a
JNDI naming environment.
• Deployment Services
– Allow components and applications to be customized at the time they are packaged and deployed.
• Transaction Services
– Devide an application into a series of indivisible or atomic units of work.
• Security Services
– Designed to ensure that resources are accessed only by users authorized to use them.
72

• Simplified architecture and development
• Scalability to meet demand variations
• Integration with existing information systems
• Choices of servers, tools, components
• Flexible security model
• The J2EE reduces the cost and complexity of developing these multi-tier services, resulting in services that can be rapidly deployed and easily enhanced as the enterprise responds to competitive pressures
.
73

• The J2EE platform is the standard environment for running J2EE applications. The J2EE platform is composed of the following elements:
–
J2EE deployment specification - a standard that defines a common way of packaging applications for deployment on any
J2EE compatible platform.
– Java technology standards for the J2EE platform - a set of standards that all J2EE platform products must support (JMS ,
JNDI etc)
–
IETF standards for the J2EE platform - a set of standards defined by the Internet Engineering Task Force that all J2EE platform products must support.(eg XML, HTTP, HTML)
– CORBA standards for the J2EE platform - a set of CORBA standards upon which the J2EE platform bases its middle-tier interoperability.
74

• A J2EE application is packaged into one or more standard units for deployment to any J2EE platformcompliant system.
• Each unit contains a functional component or components (enterprise bean, JSP page, servlet, applet, etc.), a standard deployment descriptor that describes its content, and the J2EE declarations which have been specified by the application developer and assembler.
• Once deployed, theses components can then be run.
75

• Its primary role is as an operational definition of the J2EE platform.
• Most importantly, it is used as the standard platform for running the J2EE Compatibility Test
Suite.
• A secondary role for the reference implementation is as a freely available platform for popularizing
Java 2 platform, Enterprise Edition.
76

• Latest version available for download
– Java TM 2 SDK, Enterprise Edition
Version 1.3
– Downloadable at http://java.sun.com/j2ee/
• NOTE :
– This version will require Java 2 SDK, Standard Edition
(J2SE) Version 1.3.1 or higher.
77

• Consists of
– EJB server
– Web server (HTTP)
– Secured web server (HTTPS) …
• J2EE Compliance Test
– Brings vendor neutrality to your applications
– Consists of more than 5000 tests
– Currently 9 application servers have been certified
• BEA WebLogic (BEA)
• iPlanet (Sun + Netscape)
• Websphere (IBM)
• (check out www.javasoft.com/j2ee for latest update)
78

• All Java, clean-room implementation of the J2EE
• Shipping basic APIs since 1997
• One of the most widely-used Application Servers on the market
– Over 12,000 customers
• Associated BEA product: TUXEDO
– Distributed TP Monitor
– Originally developed at Bell Labs in 1984
– Influenced the design of WebLogic
79

•
Provides a comprehensive overview of the Sun ONE
Application Server.
Please note - the tour may take up to 1 minute to complete testing your system before starting to load.
• Sun is the first software vendor to deliver a fully J2EE[tm] platform-certified, commercial application server, free of charge, on all leading OS platforms.
• The new Sun ONE Application Server 7 includes the world's fastest, secure http server, and new "Always On" technology.
Sun ONE Application Server 7 80

– Assistive Technologies
– Drag and Drop
– Java Access Bridge
– JavaBeans TM Technology
– Javadoc Tool
– Java Foundation Classes (JFC)/Swing
– Java HotSpot TM Virtual Machine
– Java Platform Debugger Architecture (JPDA)
– Java Plug-in for Windows XP
– Java 2D TM API product page
– Java Web Start
– JDBC TM Technology
– Pluggable Look and Feel
– Remote Method Invocation (RMI)
– Security
81

– Personal Profile
– Personal Basis Profile
– Java Card TM Technology
– Java Embedded Server TM Technology
– JavaPhone TM API
– Java Telematics Technology (JTT)
– Java TV TM API
– J2ME Wireless Toolkit
– PersonalJava TM Technology
– Wireless Developer web site
– Connected Limited Device Configuration (CLDC)
– Mobile Information Device Profile (MIDP)
– Connected Device Configuration (CDC)
– Foundation Profile 82

• JBoss is a simply powerful J2EE application server.
– JBoss Application Server is the #1 most widely used Java application server on the market. A J2EE certified platform for developing and deploying enterprise Java applications, Web applications, and Portals,
JBoss Application Server provides the full range of J2EE 1.4 features as well as extended enterprise services including clustering, caching, and persistence.
• EJB3.0
– JBoss Application Server includes support for Enterprise Java Beans (EJB)
3.0 which is designed to dramatically simplify the enterprise Java programming model.
• Service Oriented Architecture
– JBoss AS is founded on a service oriented microkernel architecture with an extremely small in footprint that ensures all services are accessed, managed, and integrated in a unified and consistent manner.
83

• What is Ant?
– Java-based build tool
• Why use Ant?
– Cross-platform
– Java domain smart
– Fast, extensible, integrated
– Alternatives?
• Analogy
– Factory automation
84

85

• What are you building?
• What does it take to build it?
• How are the steps related?
86

HTML /
Text files
Source Code
Index
Application
(EAR)
87

Examples of Commercially Used AOP Tools
• AspectWerkz
– Supported by BEA
• Spring AOP framework
•
JBoss AOP
• CME (Concern Manipulation
Environment)
– Supported by IBM
88

Web Tier
View - JSP
Struts - SearchForm
Commons Validator
Struts - SearchAction content
Ant build
<index> task
EJB Container
SearchSessionBean
SearchUtil API
Lucene API index
89

• Which tools are suitable for commercial dev?
– Over a dozen tools are listed on aosd.net
– Early adopters harden new technologies
– How active are the user communities of each? project
AspectJ
AspectWerkz
JBoss AOP
Spring AOP abc aspect#
AspectC++
JAC posts
150..210
each
1..30
list (november’04 posts) aspectj-users at eclipse.org
url eclipse.org/aspectj user at aspectwerkz.codehaus.org
aspectwerkz.codehaus.org aspects/jboss forum jboss.org/products/aop springframework-user abc-users at comlab.ox.ac.uk www.springframework.org abc.comlab.ox.ac.uk aspectsharp-users aspectc-user at aspect.org
jac-users at objectweb.org
aspectsharp.sourceforge.net aspectc.org
jac.objectweb.org
90

AspectJ ide eclipse, jdeveloper, jbuilder, netbeans editor views highlighting, content assist, advice links outline, visualizer, cross references
Aspect
Werkz
JBoss
AOP eclipse advice links advice links,
UI for pointcut creation aspect manager, advised members
Spring
AOP
debugger
other ajdoc, ajbrowser libs docs
++++ plain
Java
++ dynamic deployment
UI, jboss framework integration
++++ ++ spring framework integration
+++ +
91

• What ’ s it like to adopt AOP on an existing project?
AspectJ
Aspect
Werkz
JBoss
AOP
Spring
AOP source extended
.java, or .aj
plain .java
, .xml compiler incremental aspectj compile java compile, post processing checking full static checking weaving minor static checking, none of pointcuts compile and load-time, produce bytecode java compile
runtime interception and proxies deployment static deployment hot deployable run plain Java program framework invoked & managed
92

• AspectJ and AspectWerkz
– AspectJ 5 will feature support for generics in pointcuts. The
@AspectJ syntax will support the AspectWerkz annotation style
• JBoss AOP
– Static typing for parameters, performance improvements, libraries, and more IDE support features
• Spring AOP
– Performance improvements, interoperability with AspectJ's pointcuts, and packaging of some Spring AOP services as
AspectJ aspects
93

-
Lack of static checking for pointcuts
-
Advanced IDE features not yet supported
+
Rich set of enterprise aspects libraries are available and integrated with JBoss and JEMS
+
IDE support lowers adoption and reduces need to hand-code XML
+
Support for dynamic deployment of aspects http://jboss.org/products/aop
94

95

• Specifies how JBoss server components are exposed as Web service
– Stateless Session Beans
– Web components
– POJO as servlet
96

IS
CMP is an API and XML mappings
Hibernate is the actual persistence engine
Hibernate caches are being integrated with
JBossCache
Full distributed data with OR backend on one node
97

Part of JBoss full-time
Gavin King and Christian Bauer on board
Persistence for POJOs (JavaBeans)
• Flexible and intuitive mapping
• Support for fine-grained object models
• Powerful, high performance queries
• Dual-Layer Caching Architecture (HDLCA)
• Support for detached objects (no DTOs)
• Transparent Persistence
• Automatic dirty checking
• Transitive Persistence
• Smart fetching and caching
• Smooth migration to EJB3.0
• Consulting and support available as part of JBoss inc
98

• Tomcat’s Remy Maucherat is on JBoss inc staff
• Performance optimizations and reduced garbage collection
• Optional standalone deployer (validation and precompilation of webapps)
• Scalability and reliability enhancements
• Complete server monitoring using JMX
• Improved Taglibs handling, including advanced pooling and tag plugins
• Embedding of Tomcat using JMX
• Enhanced Security Manager support (now allows very restrictive policies)
• Expanded documentation
• Consulting and support available as part of JBoss inc
99

• Better JBoss deployer
– Hot deployment
– Deployment of nested archives (EARs, SARs)
– Redeployment
– Automatic undeployment
• Advanced clustering
• Integrated J2EE stack within one VM
– Deployment descriptor
– Optimized local calls
– Integrated security
• AOP in JBoss 4.0 available in Tomcat components and webapps
• Easy to use classloader
• Nukes
100

• JBoss IDE is based on Eclipse .
– Series of plugins for Eclipse
• The debugging and monitoring of JBoss servers and the control of their life cycle (start/stop).
• A very comfortable and sophisticated support for XDoclet
– Support completion and generation
– Support for AOP (completion and generation).
• An easy way to configure and deploy the packaging layout of archives
(packed or exploded)
101

• What is JBossCache?
– A transactional replicated cache for JBoss with and without AOP
(aspect-oriented programming)
• A cache for frequently accessed elements
– Stateful Session Beans, HTTPSession
– Caches are used in a number of places in JBoss
• This one provides a central cache service (MBean interface)
• All access goes through the cache
– Write-through (lazy or eager)
– Reads only access the cache (very fast on cache hits)
– Items not in the cache are loaded (e.g. from database)
– Bounded size; old items are removed by eviction policy
• Local (=non-replicated) and replicated caches
– Replicated caches are the interesting part
102

• Transactions
– All modifications done within TX, replication at TX commit. No replication on rollback
• Locking
– Access to nodes serialized by locks
– Lock acquisition timeouts used for deadlock prevention
• Replication
– local: in-VM, no replication
– repl-async: replication done on separate thread
– repl-sync: replication done on user's thread, wait for all acks
• All combinations supported
– From local/no-tx/no-locking to repl/tx/locking
– Ex: repl-async/no-locking/TX
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• Nukes on JBoss is a port of PHP postnukes
– Scalability problems with Zend engine
– Full port to EJB/J2EE.
– Leverage the vast library of nukes modules
• Most of PN modules are ported
• Core : offers the core functionalities to other modules
– Security, lifecycle management, parameterization
• User : enables user management
• Html : stores files, filesystem is abstracted, stored in DB
• Sections : edit/publish articles
• FORUMS!!!!
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1.
Write your beans and package them in an ejb-jar file.
2.
Write your servlets/JSPs and package them in a war file.
3.
Add a Class-Path attribute to your war files
MANIFEST.MF file to reference your beans package. for detailed information on that see
J2EE Deployment specification.
http://www.jboss.org
http://www.jboss.com
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4. Package your application in an ear file.
An ear file is a jar archive which contains:
• Your jar files
• Your war files
• A deployment descriptor for your application.
This file must be named "application.xml", and must be located in the META-INF directory in the ear archive. This file tells JBoss which modules are EJBs, which ones are web modules, and the context paths for the web-modules.
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<?xml version="1.0" encoding="ISO-8859-1"?>
<application> <display-name>My application</display-name>
<module>
<web>
<web-uri>webmodule.war</web-uri> <context root>/servlets</context-root>
</web>
</module>
<module>
<ejb>beans.jar</ejb>
</module>
</application>
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5. Deploy your ear file.
Option 1: Copy your ear file to
JBOSS_HOME/deploy (wow!)
Write once Deploy AnyWhere!!
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謝謝捧場 http://www.csie.nctu.edu.tw/~tsaiwn/java/
蔡文能
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