1 java 2 platform, enterprise edition (j2ee) an overview 蔡 文 能 交通大學資訊工程學系...
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TRANSCRIPT
2
What Is J2EE ?
• 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
3
Some useful online references
• http://java.sun.com
• http://java.sun.com/j2ee
• http://java.sun.com/j2ee/tutorial/index.html
4J2EE, J2SE, J2ME
J2EE and Other Java 2 Platform EditionsSource: Computer, August 2000
5Source: Sun Microsystems, Inc.
J2EE and Other Java 2 Platform Editions
J2EE, J2SE, J2ME
6Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE
Java Development and Runtime Environment
7Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE
Java 2 Platform Runtime Architecture
8Source: Sun Microsystems, Inc., http://java.sun.com/j2se/1.3/
Java 2 Platform, Standard Edition (J2SE 1.3)
9Source: Sun Microsystems, Inc., http://java.sun.com/j2se/1.4/
Java 2 Platform, Standard Edition (J2SE 1.4)
10
Why J2EE ?
• A stand alone program• Client/Server (2-Tier)
– 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
11Source: Sun Microsystems, Inc., JDBC 3.0 Specification
2-Tier Database Access
• Data Tier – Database Management Services
• Client Tier – Presentation, Business Logic
12Source: Sun Microsystems, Inc., JDBC 3.0 Specification
Traditional(non-component) N-Tier Systems
• Client Tier – Presentation Logic
• Application Tier – Business Logic
• Data Tier – Database Management Services
13
Component N-Tier SystemsJ2EE Architecture
EnterpriseInformation
Services
EnterpriseInformation
Services
Web ContainerWeb Container
JSP
Servlet
EJB ContainerEJB Container
EJB
AppletContainer
AppletContainer
StandaloneClient
StandaloneClient
Connector
Firew
ar
e
Database ServerMachine
J2EE ServerMachineClient
Machine
Web Tier Business Tier EIS Tier
Client Tier
14Source: Sun Microsystems, Inc., J2EE Specification v1.3
J2EE Architecture (1/2) J2EE Component and Container
15
J2EE Architecture (2/2)
• J2EE consists of three major parts:– Components
Hold presentation and business logic– Containers
Provide context for components– Connectors
Provide access to legacy enterprise systems
16
J2EE Components
• Application clients
• Applets
• Web components– Servelets, Java Server Pages (JSP)
– Portlet (see JSR168)
• Business components– Enterprise Java Beans (EJB)
17
J2EE ComponentApplet 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 technology-enabled 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.
18
Applet pro vs. con
• 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
19
J2EE ComponentWeb 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 text-based document that describes how to process a request to create a response
20
Java Servlet
Browser
Class Loader
Invoker
Services
WebServices
HTTP Request
HTTP Response
Servlet Class wasn’t
loaded into System
Load Servlet class
Into System
Servlet Class
was loaded
21
Java Servlet
• 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.
22
JavaServer Pages (JSP)
Browser Invoker
jspServices
WebServices
HTTP Request (.jsp)
HTTP Response
JavaSourceCode
New JSP PageJSP was modified
JavaBytecode
Compiler
Class Loader
Load Servlet class
Into System
JSP isn’t loaded yet.
23
JavaServer Pages (JSP)
• 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.
24
JavaServer PagesObjects
• JSP has 9 objects which developer can use directly without new it.
JSP Object java class scoperequest javax.servlet.ServletRequestrequestresponse javax.servlet.ServletResponse pagpageContext javax.servlet.jsp. PageContext pagesession javax.servlet.http.HttpSession
sessionapplication javax.servlet.ServletContext applicationout javax.servlet.jsp.JspWriter pageconfig javax.servlet.ServletConfig pagepage java.lang.Object pageexception java.lang.Throwable page
25
Portlet and Portal
Portal Server
Browser
JSR168 Portlet Container
JSR168 Portlet
JSR168 Portlet
HTTP
WSRP
• JSR168– Java portlet
standard
• WSRP– Remote portlet
communication protocol
– Portals aggregate remote portlets
(Web Services for Remote Portlets )
26
The Reason For JDBC
• 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
CCTM: Course material developed by James King ([email protected])
27
JDBC• 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
CCTM: Course material developed by James King ([email protected])
28
Rollback and Commit
• 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 changesconnection.rollback() to undo changes since the last commit• You can switch auto commit back on usingconnection.setAutoCommit(true)
CCTM: Course material developed by James King ([email protected])
29
J2EE Compoent (1/2)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.
30
EJB Component (2/2)
• 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 message-driven beans.
31
Enterprise Bean Objects
• Session objects: for a single client, short-lived, …Stateful, Stateless
• Entity objects: object view of data in the database, shared by multiple clients, long-lived, …
• Message-driven objects: triggered by a single client message, short-lived, stateless, …
32
Stateful vs. Stateless Session Beans
• 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
33
Entity Beans: CMP vs. BMP
• 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
34
Entity Bean Characteristics
• Provides an object view of data in the underlying database
• Shared across multiple users
• Long-lived
• Survives container crash
35
To Implement an Enterprise Bean (1/2)
• 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
36
To Implement an EJB (2/2)
• 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)
37
EJB Container
• 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
38
Basic Services Supplied by the EJB Container
• Security
• Transaction management
• Remote Client Connectivity
• Life Cycle Management
• Database Connection Pooling
39
More Services provided by container
• 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
40
Can’t Do in an EJB
• 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
41
EJB Benefits Summary
• 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
42
J2EE Containers (1/2) 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.
43
J2EE Containers (2/2) 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.
44
Tomcat
• 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)
45
Tomcat and Apache
• 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
46
J2EE Connectors
• Contract between container and Enterprise Information Systems (EIS)
• Proprietary and under the hood
• Implementation is available with J2EE specification version 1.3 / 1.4
47
J2EE Standard Services
• 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
48
The Solution: J2EE Application Model
• 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.
49Source: Sun Microsystems, Inc., http://java.sun.com/j2ee/overview2.html
J2EE Application Model
50
Benefits of J2EE Application Model
• 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.
51
J2EE Platform Roles
• J2EE Product Provider
• Application Component Provider
• Application Assembler
• Deployer
• System Administrator
• Tool Provider
52
The Connector Architecture
• Integration of J2EE servers with Enterprise Information Systems (EIS)
• EIS vendor-provided resource adaptors
• Resource adaptor-permitting application servers
53
J2EE Connector
• 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.
54Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification
System Level Pluggability
55Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification
Connector Architecture Overview
56
Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification
Connector Architecture Overview (cont.)
57Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification
Connector Architecture in B2B Scenario
58
Client View of an Enterprise Bean
• 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
59Source: Sun Microsystems, Inc., Enterprise JavaBeans 2.0
Client View of Session Beans
60Source: Sun Microsystems, Inc., J2EE Specification, v1.3
Accessing Enterprise Beans from Servlets/JavaServer Pages
61
Source: Sun Microsystems, Inc., J2EE Specification, v1.3
J2EE Deployment
62Source: Sun Microsystems, Inc., J2EE Connector Architecture Specification
J2EE Application Life Cycle
63Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE
Overview of Enterprise Applications Integration (EAI)
64Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE
Overview of Enterprise Applications Integration (EAI)
65Source: P.J. Perrone and V.S.R.R. Chaganti, Building Java Enterprise Systems with J2EE
EAI with XML
66Source: Sun Microsystems, Inc., The J2EE Tutorial
Enterprise Beans of the Example Design
67
J2EE Platform Technologies 1/3
• 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.
68
J2EE Platform Technologies 2/3
• 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.
69
J2EE Platform Technologies 3/3
• 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.
70
History of J2EE Technologies
• 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
72
J2EE Platform Services
• 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.
73
J2EE Platform Benefits
• 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.
74
J2EE Platform• 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.
75
J2EE Application Assembly
• A J2EE application is packaged into one or more standard units for deployment to any J2EE platform-compliant 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.
76
J2EE Reference Implementation
• 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.
77
J2EE Reference Implementation• Latest version available for download
– JavaTM 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.
78
Application Servers
• 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)
79
The BEA WebLogic Server
• 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
80
Sun ONE Application Server 7
• 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
81
J2SE Component Links – Assistive Technologies– Drag and Drop– Java Access Bridge– JavaBeansTM Technology– Javadoc Tool– Java Foundation Classes (JFC)/Swing– Java HotSpotTM Virtual Machine– Java Platform Debugger Architecture (JPDA)– Java Plug-in for Windows XP– Java 2DTM API product page– Java Web Start– JDBCTM Technology– Pluggable Look and Feel– Remote Method Invocation (RMI)– Security
82
List of J2ME Technologies– Personal Profile– Personal Basis Profile– Java CardTM Technology– Java Embedded ServerTM Technology– JavaPhoneTM API– Java Telematics Technology (JTT)– Java TVTM API– J2ME Wireless Toolkit– PersonalJavaTM Technology– Wireless Developer web site– Connected Limited Device Configuration (CLDC)– Mobile Information Device Profile (MIDP)– Connected Device Configuration (CDC)– Foundation Profile
83
JBoss Application Server
• 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.
84
Introduction to Apache Ant
• What is Ant?– Java-based build tool
• Why use Ant?– Cross-platform– Java domain smart– Fast, extensible, integrated– Alternatives?
• Analogy– Factory automation
85
Typical Things to Build
86
Designing a Build
• What are you building?
• What does it take to build it?
• How are the steps related?
87
High-level Model
HTML /Textfiles
IndexApplication
(EAR)
Source Code
88
Examples of Commercially Used AOP Tools
• AspectWerkz – Supported by BEA
• Spring AOP framework
• JBoss AOP
• CME (Concern Manipulation Environment)– Supported by IBM
89
Technical Architecture
SearchSessionBean
SearchUtil API
Lucene API
EJB Container
Struts - SearchAction
View - JSPStruts - SearchFormCommons Validator
Web Tier
index
Ant build<index>
task
content
90
AOP – Aspect Oriented Programming• 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 posts list (november’04 posts) url
AspectJ
150..210each
aspectj-users at eclipse.org eclipse.org/aspectj
AspectWerkz
user at aspectwerkz.codehaus.org
aspectwerkz.codehaus.org
JBoss AOP aspects/jboss forum jboss.org/products/aop
Spring AOP springframework-user www.springframework.org
abc
1..30
abc-users at comlab.ox.ac.uk abc.comlab.ox.ac.uk
aspect# aspectsharp-users aspectsharp.sourceforge.net
AspectC++ aspectc-user at aspect.org aspectc.org
JAC jac-users at objectweb.org jac.objectweb.org
91
IDE support, libs, and docside editor views debugger other libs docs
AspectJ
eclipse, jdeveloper,jbuilder, netbeans
highlighting, content assist, advice links
outline, visualizer,cross references
plain Java
ajdoc, ajbrowser
-+++
+
AspectWerkz
eclipse
advice links
- - - ++
JBoss AOP
advice links, UI for pointcut creation
aspect manager,advised members
dynamic deployment UI, jboss framework integration
++++
++
Spring AOP -
spring framework integration
+++ +
92
Building AOP programs• What’s it like to adopt AOP on an existing
project?source compiler checking weaving deployment run
AspectJ
extended
.java, or .aj
incremental aspectj compile
full static checking
compile and load-time, produce bytecode
static deployment plain
Java program
AspectWerkz
plain .java, .xml
java compile, post processing
minor static checking, none of pointcuts
hot deployable
JBoss AOP runtime
interception and proxies
framework invoked & managed
Spring AOP
java compile -
93
AOP features
• 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
94
JBoss AOP (1/2)
- 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
95
JBoss AOP (2/2)
96
Web services in JBoss Overview: JBoss.net• Specifies how JBoss server components are exposed as Web
service– Stateless Session Beans– Web components– POJO as servlet
97
JBoss Hibernate
Hibernate IS EJB 3.0 CMPCMP 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
98
HibernatePart 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
99
Tomcat 5.0.x improvements
• 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
100
Tomcat standalone or Tomcat inside JBoss ?
• 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
101
JBoss IDE
• 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)
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What Is JBossCache?• 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
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Feature• 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 ™
• 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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CMS: ease of update for non-techies
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Nukes components
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How to Deploy on JBoss (1/3)
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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How to Deploy in JBoss (2/3)
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 belocated in the META-INF directory in the ear archive. Thisfile tells JBoss which modules are EJBs, which ones areweb modules, and the context paths for the web-modules.
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Sample Application.xml file
<?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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How to Deploy in JBoss (3/3)
5. Deploy your ear file.
Option 1: Copy your ear file to JBOSS_HOME/deploy (wow!)
Write once Deploy AnyWhere!!
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Thank you!
謝謝捧場http://www.csie.nctu.edu.tw/~tsaiwn/java/
蔡文能
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