Knowledge Rack http://elearning.cordinize.com/knowledge/index.php How To Install Android SDk??? http://elearning.cordinize.com/knowledge/index.php?entry=entry091001-033556 System Requirements

1. Supported Operating Systems

* Windows XP (32-bit) or Vista (32- or 64-bit)

* Mac OS X 10.4.8 or later (x86 only)

* Linux (tested on Linux Ubuntu Hardy Heron)


2. Supported Development Environments

* Eclipse 3.4 (Ganymede) or 3.5 (Galileo)

* JDK 5 or JDK 6 (JRE alone is not sufficient)

* Android Development Tools plugin (optional)

* Not compatible with Gnu Compiler for Java (gcj)


3. Other Development Environments or IDEs

* JDK 5 or JDK 6 (JRE alone is not sufficient)

* Apache Ant 1.6.5 or later for Linux and Mac, 1.7 or later for Windows

• Not compatible with Gnu Compiler for Java (gcj)


Install android_sdk_windows_1.6

After downloading the Android SDK, unpack the Android SDK.zip archive to a suitable location on your machine. By default, the SDK files are unpacked into a directory named android_sdk_ <platform>_<release>. Here we are going to install android-sdk-windows-1.6_r1.

Make a note of the name and location of the unpacked SDK directory on your system — you will need to refer to the SDK directory later, when setting up the Android plugin or when using the SDK tools.

Optionally, you may want to add the location of the SDK's primary tools directory to your system PATH. The primary tools/ directory is located at the root of the SDK folder. Adding tools to your path lets you run Android Debug Bridge (adb) and the other command line tools without needing to supply the full path to the tools directory.

• On Windows,

1. Rright-click on My Computer, and select Properties.

2. Under the Advanced tab, hit the Environment Variables button, and in the dialog that comes up,

3. Double-click on Path (under System Variables).

4. Add the full path to the tools/ directory to the path.

Example:
Set variable name as path &
variable value as,like D:\android-sdk-1.6_r1\tools

• On Linux,

1. Edit your ~/.bash_profile or ~/.bashrc file.

2. Look for a line that sets the PATH environment variable and

3. Add the full path to the tools/ directory to it. If you don't see a line setting the path, you can add one:
export PATH=${PATH}:<your_sdk_dir>/tools

• On a Mac,

Look in your home directory for .bash_profile and proceed as for Linux. You can create the .bash_profile if you haven't already set one up on your machine.

Note that, if you update your SDK in the future, you should remember to update your PATH settings to point to the new location, if different.

If you will be using the Eclipse IDE as your development environment, the next section describes how to install the Android Development Tools (ADT) plugin and set up Eclipse. If you choose not to use Eclipse, you can develop Android applications in an IDE of your choice and then compile, debug and deploy using the tools included in the SDK (skip to Next Steps).


Install the ADT Plugin for Eclipse

Android offers a custom plugin for the Eclipse IDE, called Android Development Tools (ADT), that is designed to give you a powerful, integrated environment in which to build Android applications. It extends the capabilites of Eclipse to let you quickly set up new Android projects, create an application UI, add components based on the Android Framework API, debug your applications using the Android SDK tools, and even export signed (or unsigned) APKs in order to distribute your application.
In general, using Eclipse with ADT is a highly recommended approach to Android development and is the fastest way to get started. (If you prefer to work in an IDE other than Eclipse, you do not need to install Eclipse or ADT, instead, you can directly use the SDK tools to build and debug your application—skip to Next Steps.)

Once you have the Eclipse IDE installed, as described in Preparing for Installation, follow the steps below to download the ADT plugin and install it in your respective Eclipse environment.


Eclipse 3.4 (Ganymede)

1. Start Eclipse, then select Help > Software Updates.... In the dialog that appears, click the Available Software tab.

2. Click Add Site...

3. In the Add Site dialog that appears, enter this URL in the "Location" field:
https://dl-ssl.google.com/android/eclipse/

Note: If you have trouble aqcuiring the plugin, try using "http" in the Location URL, instead of "https" (https is preferred for security reasons).

4. Click OK.

5. Back in the Available Software view, you should see the plugin listed by the URL, with "Developer Tools" nested within it. Select the checkbox next to Developer Tools and click Install...

6. On the subsequent Install window, "Android DDMS" and "Android Development Tools" should both be checked. Click Next.

7. Read and accept the license agreement, then click Finish

8. Restart Eclipse


Eclipse 3.5 (Galileo)

1. Start Eclipse, then select Help > Install New Softare.

2. In the Available Software dialog, click Add....

3. In the Add Site dialog that appears, enter a name for the remote site (e.g., "Android Plugin") in the "Name" field.
In the "Location" field, enter this URL:

https://dl-ssl.google.com/android/eclipse/

Note: If you have trouble aqcuiring the plugin, you can try using "http" in the URL, instead of "https" (https is preferred for security reasons).
Click Ok

4. Back in the Available Software view, you should now see "Developer Tools" added to the list. Select the checkbox next to Developer Tools, which will automatically select the nested tools Android DDMS and Android

5 In the resulting Install Details dialog, the Android DDMS and Android Development Tools features are listed. Click Next to read and accept the license agreement and install any dependencies, then click Finish.

6. Restart Eclipse.


Now modify your Eclipse preferences to point to the Android SDK directory:

1. Select Window > Preferences... to open the Preferences panel (Mac: Eclipse > Preferences).

2. Select Android from the left panel.

3. For the SDK Location in the main panel, click Browse... and locate your downloaded SDK directory.

4. Click Apply, then OK.



Done! If you haven't encountered any problems, then you're ready to begin developing Android applications.
]]> WSDL http://elearning.cordinize.com/knowledge/index.php?entry=entry091001-003046 WSDL (Web Services Description Language)

As communications protocols and message formats are standardized in the web community, it becomes increasingly possible and important to be able to describe the communications in some structured way.WSDL addresses this need by defining an XML grammar for describing network services as collections of communication endpoints capable of exchanging messages.

WSDL service definitions provide documentation for distributed systems and serve as a recipe for automating the details involved in applications communication

A WSDL document defines services as collections of network endpoints, or ports. In WSDL, the abstract definition of endpoints and messages is separated from their concrete network deployment or data format bindings. This allows the reuse of abstract definitions: messages, which are abstract descriptions of the data being exchanged, and port types which are abstract collections of operations. The concrete protocol and data format specifications for a particular port type constitutes a reusable binding. A port is defined by associating a network address with a reusable binding, and a collection of ports define a service. Hence, a WSDL document uses the following elements in the definition of network services:

• Types– a container for data type definitions using some type system (such as XSD).

• Message– an abstract, typed definition of the data being communicated.

• Operation– an abstract description of an action supported by the service.

• Port Type–an abstract set of operations supported by one or more endpoints.

• Binding– a concrete protocol and data format specification for a particular port type.

• Port– a single endpoint defined as a combination of a binding and a network address.

• Service– a collection of related endpoints.

It is important to observe that WSDL does not introduce a new type definition language. WSDL recognizes the need for rich type systems for describing message formats, and supports the XML Schemas specification (XSD) [11] as its canonical type system. However, since it is unreasonable to expect a single type system grammar to be used to describe all message formats present and future, WSDL allows using other type definition languages via extensibility.

In addition, WSDL defines a common binding mechanism. This is used to attach a specific protocol or data format or structure to an abstract message, operation, or endpoint. It allows the reuse of abstract definitions.

In addition to the core service definition framework, this specification introduces specific binding extensions for the following protocols and message formats:

• SOAP 1.1
• HTTP GET / POST
• MIME

Structure Of A WSDL Document

<definitions>

<types>

definition of types........

</types>

<message>

definition of a message....

</message>

<portType>

definition of a port.......

</portType>

<binding>

definition of a binding....

</binding>

</definitions>
]]> Android http://elearning.cordinize.com/knowledge/index.php?entry=entry090930-235514 Android is a Linux-based open source platform for mobile cellular handsets. Android was developed by Google and the Open Handset Alliance (OHA), a coalition of hardware, software and telecommunications companies oriented towards advancing mobile telephony standards.


Android platform includes an operating system based upon Linux, a GUI, a Web browser and many other applications considered key to a modern cellular handset. Android allows synchronization to a user's address book, calendar and other personal information management (PIM) programs, though individual software makers will have to customize their offerings.


Android will allow users to browse the Internet more easily, integrate mapping services with local business listings and use many other software features traditionally associated with personal computers rather than cellphones.


Android will run on both of the most widely deployed cellular standards, GSM/HSDPA and CDMA/EV-DO.

Android will also support:

• Bluetooth
• EDGE
• 3G Communication Protocols, like EV-DO and HSDPA
• WiFi
• SMS messaging
• MMS
• Video/Still Digital Cameras
• Touchscreens
• GPS
• Compasses
• Accelerometers
• Accelerated 3D Graphics

Android includes software built by many different entities. For instance, the default Android web browser will be based on Webkit, like Apple's Safari. Webkit was originally based on the Konquerer Web browser for Linux. Its music and video playback software was developed by PacketVideo. Applications are written using Java and are run on Dalvik, a virtual machine that runs on top of a Linux kernel.





]]> Android Architecture http://elearning.cordinize.com/knowledge/index.php?entry=entry090930-071127 Android Architecture


Applications

Android will ship with a set of core applications including an email client, SMS program, calendar, maps, browser, contacts, and others. All applications are written using the Java programming language.

Application Framework

Developers have full access to the same framework APIs used by the core applications. The application architecture is designed to simplify the reuse of components. Any application can publish its capabilities and any other application may then make use of those capabilities (subject to security constraints enforced by the framework). This same mechanism allows components to be replaced by the user.

Underlying all applications is a set of services and systems, including:

• A rich and extensible set of Views that can be used to build an application, including lists, grids, text boxes, buttons, and even an embeddable web browser
• Content Providers that enable applications to access data from other applications (such as Contacts), or to share their own data
• A Resource Manager, providing access to non-code resources such as localized strings, graphics, and layout files
• A Notification Manager that enables all applications to display custom alerts in the status bar
• An Activity Manager that manages the lifecycle of applications and provides a common navigation back stack

Libraries

Android includes a set of C/C++ libraries used by various components of the Android system. These capabilities are exposed to developers through the Android application framework. Some of the core libraries are listed below:

• System C library - a BSD-derived implementation of the standard C system library (libc), tuned for embedded Linux-based devices
• Media Libraries - based on Packet Video’s Open CORE; the libraries support playback and recording of many popular audio and video formats, as well as static image files, including MPEG4, H.264, MP3, AAC, AMR, JPG, and PNG
• Surface Manager - manages access to the display subsystem and seamlessly composites 2D and 3D graphic layers from multiple applications
• LibWebCore - a modern web browser engine which powers both the Android browser and an embeddable web view
• SGL - the underlying 2D graphics engine
• 3D libraries - an implementation based on OpenGL ES 1.0 APIs; the libraries use either hardware 3D acceleration (where available) or the included, highly optimized 3D software.
• Free Type - bitmap and vector font rendering
• SQLite - a powerful and lightweight relational database engine available to all applications

Android Runtime

Android includes a set of core libraries that provides most of the functionality available in the core libraries of the Java programming language.
Every Android application runs in its own process, with its own instance of the Dalvik virtual machine. Dalvik has been written so that a device can run multiple VMs efficiently. The Dalvik VM executes files in the Dalvik Executable (.dex) format which is optimized for minimal memory footprint. The VM is register-based, and runs classes compiled by a Java language compiler that have been transformed into the .dex format by the included "dx" tool.
The Dalvik VM relies on the Linux kernel for underlying functionality such as threading and low-level memory management.

Linux Kernel

Android relies on Linux version 2.6 for core system services such as security, memory management, process management, network stack, and driver model. The kernel also acts as an abstraction layer between the hardware and the rest of the software stack.

]]> Introduction to Android http://elearning.cordinize.com/knowledge/index.php?entry=entry090930-065102 Introduction to Android

Android is a Java-based operating system that runs on the Linux 2.6 kernel, developed by Google and later the Open Handset Alliance. It allows developers to write managed code in a Java-like language that utilizes Google-developed Java libraries, but does not support programs developed in native code. The system is very lightweight and full featured.

Features of Android

• Android apps can be developed on any platform (Windows XP and Vista, Linux, and Mac OS)
• Anyone can develop and launch an Android application.
• Android applications can be available in the Android Market instantly.
• Android supports touch screen, accelerometer, GPS, WiFi, SMS, still camera, MMS, video camera and Bluetooth.
• Android has some fresh ideas like Google Maps "street view" and customizable home page.
• Applications on an Android handset can run in parallel.
• Accelerated 3-D graphics engine (based on hardware support).
• Integrated web browser.
• Third-party applications are executed with the same system priority as those that are bundled with the core system.
]]> Service Oriented Architecture http://elearning.cordinize.com/knowledge/index.php?entry=entry090929-230510 Service Oriented Architecture

A service-oriented architecture is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed (Or) Service-oriented architecture (SOA) is an evolution of distributed computing based on the request/reply design paradigm for synchronous and asynchronous applications. An application's business logic or individual functions are modularized and presented as services for consumer/client applications. What's key to these services is their loosely coupled nature; i.e., the service interface is independent of the implementation. Application developers or system integrators can build applications by composing one or more services without knowing the services' underlying implementations. For example, a service can be implemented either in .Net or J2EE, and the application consuming the service can be on a different platform or language.

SOA is not Web services

"Web services are about technology specifications, whereas SOA is a software design principle. Notably, Web services' WSDL is an SOA-suitable interface definition standard: this is where Web services and SOA fundamentally connect." Fundamentally, SOA is an architectural pattern, while Web services are services implemented using a set of standards; Web services is one of the ways you can implement SOA. The benefit of implementing SOA with Web services is that you achieve a platform-neutral approach to accessing services and better interoperability as more and more vendors support more and more Web services specifications.

Service-oriented architectures have the following key characteristics:

• SOA services have self-describing interfaces in platform-independent XML documents. Web Services Description Language (WSDL) is the standard used to describe the services.

• SOA services communicate with messages formally defined via XML Schema (also called XSD). Communication among consumers and providers or services typically happens in heterogeneous environments, with little or no knowledge about the provider. Messages between services can be viewed as key business documents processed in an enterprise.

• SOA services are maintained in the enterprise by a registry that acts as a directory listing. Applications can look up the services in the registry and invoke the service. Universal Description, Definition, and Integration (UDDI) is the standard used for service registry.

• Each SOA service has a quality of service (QoS) associated with it. Some of the key QoS elements are security requirements, such as authentication and authorization, reliable messaging, and policies regarding who can invoke services.

Why SOA?

The reality in IT enterprises is that infrastructure is heterogeneous across operating systems, applications, system software, and application infrastructure. Some existing applications are used to run current business processes, so starting from scratch to build new infrastructure isn't an option. Enterprises should quickly respond to business changes with agility; leverage existing investments in applications and application infrastructure to address newer business requirements; support new channels of interactions with customers, partners, and suppliers; and feature an architecture that supports organic business. SOA with its loosely coupled nature allows enterprises to plug in new services or upgrade existing services in a granular fashion to address the new business requirements, provides the option to make the services consumable across different channels, and exposes the existing enterprise and legacy applications as services, thereby safeguarding existing IT infrastructure investments.

The vision behind service-oriented computing is extremely ambitious and therefore also very attractive to any organization interested in truly improving the effectiveness of its IT enterprise. A set of common goals and benefits has emerged to form this vision. These establish a target state for an enterprise that successfully adopts service-orientation.

Basic Service Oriented Architecture Diagram



It shows a service consumer at the right sending a service request message to a service provider at the left. The service provider returns a response message to the service consumer. The request and subsequent response connections are defined in some way that is understandable to both the service consumer and service provider. How those connections are defined is explained in Web Services . A service provider can also be a service consumer.

SOA infrastructure

To run and manage SOA applications, enterprises need an SOA infrastructure that is part of the SOA platform. An SOA infrastructure must support all the relevant standards and required runtime containers. A typical SOA infrastructure looks like



A typical SOA infrastructure


WSDL, UDDI, SOAP

WSDL is used to describe the service; UDDI, to register and look up the services; and SOAP, as a transport layer to send messages between service consumer and service provider. While SOAP is the default mechanism for Web services, alternative technologies accomplish other types of bindings for a service. A consumer can search for a service in the UDDI registry, get the WSDL for the service that has the description, and invoke the service using SOAP.

WS-I Basic Profile

WS-I Basic Profile, provided by the Web services Interoperability Organization, is turning into another core piece required for service testing and interoperability. Service providers can use the Basic Profile test suites to test a service's interoperability across different platforms and technologies.

J2EE and .Net

Though the J2EE and .Net platforms are the dominant development platforms for SOA applications, SOA is not by any means limited to these platforms. Platforms such as J2EE not only provide the framework for developers to naturally participate in the SOA, but also, by their inherent nature, bring a mature and proven infrastructure for scalability, reliability, availability, and performance to the SOA world. Newer specifications such as Java API for XML Binding (JAXB), used for mapping XML documents to Java classes, Java API for XML Registry (JAXR), used for interacting with the UDDI registries in a standard manner, and Java API for XML-based Remote Procedure Call (XML-RPC), used for invoking remote services in J2EE 1.4 facilitate the development and deployment of Web services that are portable across standard J2EE containers, while simultaneously interoperating with services across other platforms such as .Net.

Security

The Web Services Security specification addresses message security. This specification focuses on credential exchange, message integrity, and message confidentiality. The attractive thing about this specification is it leverages existing security standards, such as Security Assertion Markup Language (SAML), and allows the usage of these standards to secure Web services messages.

Reliability

In a typical SOA environment, several documents are exchanged between service consumers and service providers. Delivery of messages with characteristics like once-and-only-once delivery, at-most-once delivery, duplicate message elimination, guaranteed message delivery, and acknowledgment become important in mission-critical systems using service architecture. WS-Reliability and WS-ReliableMessaging are two standards that address the issues of reliable messaging. Both these standards are now part of OASIS.

Policy

Service providers sometimes require service consumers to communicate with certain policies. As an example, a service provider may require a Kerberos security token for accessing the service. These requirements are defined as policy assertions. A policy may consist of multiple assertions. WS-Policy standardizes how policies are to be communicated between service consumers and service providers.

Orchestration

As enterprises embark on service architecture, services can be used to integrate silos of data, applications, and components. Integrating applications means that the process requirements, such as asynchronous communication, parallel processing, data transformation, and compensation, must be standardized. BPEL4WS or WSBPEL (Web Services Business Process Execution Language) is an OASIS specification that addresses service orchestration, where business processes are created using a set of discrete services..

Management

As the number of services and business processes exposed as services grow in the enterprise, a management infrastructure that lets the system administrators manage the services running in a heterogeneous environment becomes important. Web Services for Distributed Management (WSDM) will specify that any service implemented according to WSDM will be manageable by a WSDM-compliant management solution.






]]> What is Identity Management? http://elearning.cordinize.com/knowledge/index.php?entry=entry090610-070850
Identity management encompasses all the processes used to create and manage information system user accounts. In the information system world, the creation of private networks, where users had to identify themselves with a user name and password occurred first. Only as systems expanded and the field of computer science grew into the Internet in the early 1990’s, did the role of the public or general user develop.

As a result of this expansion, identity management has evolved from a centrally controlled user ID process managed by a "gatekeeper" into a system of user driven self service. Users are now responsible for password resetting and management, downloading a central function of system maintenance away from the technical staff and placing this role in the hands of the user community. To address this shift in process, complex workflows surrounding the management of user access, approvals and account management has been developed.

With the huge expansion in the use of information systems in everyday life and in the workplace, identify management has become increasingly important. The original concept of a series of independent systems led to an unexpected problem. With the rapid increase in the number of systems, the number of unique user IDs users were required to maintain multiplied.

In response to the fear of security breaches, the required complexity of identify management solutions grew. The minimum number of characters in a password increased, as did the requirement for a combination of letters, numbers and characters. These changes were made in an attempt to reduce the effectiveness of computerized programs designed to break the identity management system. This shift actually reduced the quality of the security provided in an identity management system, as users simply write down the system name, their user ID and the password on paper or in another software tool in an attempt to manage this data.]]> Content Management - Why anymore papers have content at your finger tips http://elearning.cordinize.com/knowledge/index.php?entry=entry090127-064236
How widespread is this problem?
Like what John K. Waters said that more than 80 percent of the information that companies generate is unstructured and that managing it has become critical. "Just about every company is coping with an explosion of [data]," he writes, and finding ways to use that unstructured data has become "a competitive differentiator."

Now the world knows that there is a huge team of people working on a better way to support how information is generated,
maintained and delivered to clients and finally the destruction of these information at the end of thier lifecycle.

ISNT THAT JUST AMAZING .Yes we have a solution now ORACLE CONTENT MANAGEMENT - THE ENTERPRISE 2.0 TECHNOLOGY

What does it do? whats its purpose?
Oracle's content management solution is centered around two new database options. Oracle Content Database (Oracle Content DB) enables customers to manage large volumes of unstructured content in a single Oracle database. Oracle Records Database (Oracle Records DB) provides for the lifecycle management of electronic records, so organizations can fulfill regulatory compliance mandates in an accurate, repeatable way.

Both of these options use Oracle Database 10g as the repository for storing and managing unstructured content. "Customers can now use Oracle Database 10g to store everything: data; files; metadata; text indexes; relationships between objects, security, and access control,"."Everything you need to know about your content is in there, and it's all managed in a consistent, auditable, highly controlled way. Unlike the proprietary content management systems of the past, Oracle has created easy-to-use Windows and Web interfaces to help organizations more easily control, secure, and manage large volumes of structured and unstructured content."

Oracle Content Management offers the most unified, usable enterprise content management (ECM) platform in today’s market. With centralized control across single or multiple repositories, common core functionality, and easily scalable content management capabilities, Oracle provides content management solutions for all content types and all users—wherever they work in the enterprise. And because it’s built on Oracle Fusion Middleware, Oracle Content Management integrates seamlessly with Oracle’s other solutions—including business intelligence, business integration, and process management—making content management an important part of your overall business strategy.

BUT then again the competition on this space is still strong :)with DOCUMENTUM sometimes trying to take the lead. ]]> GWT over AJAX http://elearning.cordinize.com/knowledge/index.php?entry=entry080710-004953 AJAX Overview

AJAX (Asynchronous JavaScript and XML) evolved in an effort to solve difficult problems, by allowing the browser to communicate with the server, behind the scenes, without having to refresh the entire page. It accomplishes this by using JavaScript to only change that portion of the current Web page that needs to be changed. AJAX can make the user's browser behave more like a desktop application, combining server interaction with far greater performance than traditional server-side languages. AJAX is asynchronous in the sense that the needed data is obtained from the server and loaded without interfering with the display and behavior of the current Web page. The data is requested through use of the XMLHttpRequest object, and typically formatted in XML.

But raw AJAX programming can be quite difficult, partly because AJAX code is typically quite daunting, and partly because Web browsers have implemented JavaScript differently, despite a convergence upon ECMAScript standards, promulgated by the European Computer Manufacturers Association (ECMA). As a result, AJAX programmers can spend much of their development time dealing with incompatibilities among browsers and operating systems.

One of the main problems with Ajax development is that you need to master a large stack of heterogeneous technologies. Depending on the nature of your project (for example, business applications), this can be a great drawback.

In addition, different Web browsers don’t support JavaScript and DHTML in the same way. For example, Microsoft Internet Explorer and Mozilla Firefox handle these technologies slightly differently, you’ll need to deal with this if you want your application to run seamlessly on your users’ PCs.

Although most of the Ajax frameworks available today simplify development work, you still need a good grasp of the technology stack. So, if you’re planning to use Ajax to improve only your application’s user experience—if you’re not also using it as a strategic advantage for your business—it may be unwise to spend a lot of money and time on the technology.

GWT to rescue

Google Web Toolkit (GWT), an open source software development framework that allows the programmer to write Java code, which then gets translated into AJAX code. More specifically, the GWT compiler converts the Java classes into browser-compliant HTML and JavaScript code.

The key idea is that GWT is intended to make AJAX programming much easier — especially for programmers already adept with Java.

GWT provides specific APIs to manage the GUI, internationalization, and XML parsing. It also provides a comprehensive library to manage communication between the client and the server. It uses well-known Remote Procedure Call (RPC) principles implemented by a generic servlet (RemoteServiceServlet), which you can specialize for your own needs. You also can use JavaScript Object Notation (JSON) as the data interchange format for your HTTP messages sent with the GWT HTTPRequest class.

GWT also offers an interface, called JavaScript Native Interface (JSNI), which lets you mix your own hand-made JavaScript code with the code generated by the GWT compiler. JSNI uses the keyword native used by Java Native Interface (JNI) to define your own JavaScript functions. The body of these functions is defined inside specifically formatted comments.

The well-known concepts of GUI programming are available with GWT:

* Widgets, including the usual items (such as Button, TextBox, and CheckBox) and more advanced items such as Tree and Menu Bar
* Panels, which contain widgets, with their own layout (panels and layout aren’t separated as in Swing)
* Events generated by widgets. The listeners must implement specific interfaces.

GWT uses Cascading Style Sheets (CSS). Every widget has its own style, which you can change to meet your needs. You must create your own CSS to overload the defaults defined by GWT.]]> Web Services http://elearning.cordinize.com/knowledge/index.php?entry=entry080415-104919 Web Services
A web service is any service that is available over the Internet, uses a standardized XML messaging system, and is not tied to any one operating system or programming language.
There are several alternatives for XML messaging. For example, you could use XML Remote Procedure Calls (XML-RPC) or SOAP. Alternatively, you could just use HTTP GET/POST and pass arbitrary XML documents.

To summarize, a complete web service is , therefore, any service that:
• Is available over the Internet or private (intranet) networks
• Uses a standardized XML messaging system
• Is not tied to any one operating system or programming language
• Is self-describing via a common XML grammar
• Is discoverable via a simple find mechanism

There are currently many competing frameworks and proposals for web services. The three main contenders are Microsoft's .NET, IBM Web Services, and Sun Open Net Environment (ONE). All of the frameworks share a common set of technologies, mainly SOAP, WSDL, and UDDI.

Web Service Architecture
There are two ways to view the web service architecture. The first is to examine the individual roles of each web service actor , the second is to examine the emerging web service protocol stack.

1.Web Service Roles
There are three major roles within the web service architecture:
• Service provider
This is the provider of the web service. The service provider implements the service and makes it available on the Internet.
• Service requestor
This is any consumer of the web service. The requestor utilizes an existing web service by opening a network connection and sending an XML request.
• Service registry
This is a logically centralized directory of services. The registry provides a central place where developers can publish new services or find existing ones. It therefore serves as a centralized clearinghouse for companies and their services.

2.Web Service Protocol Stack
Currently there are four main layers
• Service transport
This layer is responsible for transporting messages between applications. Currently, this layer includes hypertext transfer protocol (HTTP), Simple Mail Transfer Protocol (SMTP), file transfer protocol (FTP), and newer protocols, such as Blocks Extensible Exchange Protocol (BEEP).
• XML messaging
This layer is responsible for encoding messages in a common XML format so that messages can be understood at either end. Currently, this layer includes XML-RPC and SOAP.
• Service description
This layer is responsible for describing the public interface to a specific web service. Currently, service description is handled via the Web Service Description Language(WSDL).
• Service discovery
This layer is responsible for centralizing services into a common registry, and
providing easy publish/find functionality. Currently, service discovery is handled via Universal Description, Discovery, and Integration (UDDI).
As web services evolve, additional layers may be added, and additional technologies may be added to each layer.

]]> Java Virtual Machine http://elearning.cordinize.com/knowledge/index.php?entry=entry080325-152811 What is JVM(Java Virtual Machine) and how it works??

At the heart of the Java platform lies the Java Virtual Machine, or JVM. Most programming languages compile source code directly into machine code, suitable for execution on a particular microprocessor architecture. The difference with Java is that it uses bytecode - a special type of machine code.

java bytecode executes on a special type of microprocessor. Strangely enough, there wasn’t a hardware implementation of this microprocessor available when Java was first released. Instead, the processor architecture is emulated by what is known as a “virtual machine”. This virtual machine is an emulation of a real Java processor - a machine within a machine. The only difference is that the virtual machine isn’t running on a CPU - it is being emulated on the CPU of the host machine.

The Java Virtual Machine is responsible for interpreting Java bytecode, and translating this into actions or operating system calls.

For example, a request to establish a socket connection to a remote machine will involve an operating system call. Different operating systems handle sockets in different ways - but the programmer doesn’t need to worry about such details. It is the responsibility of the JVM to handle these translations, so that the operating system and CPU architecture on which Java software is running is completely irrelevant to the developer.

The Java Virtual Machine forms part of a large system, the Java Runtime Environment (JRE). Each operating system and CPU architecture requires a different JRE. The JRE comprises a set of base classes, which are an implementation of the base Java API, as well as a JVM. The portability of Java comes from implementations on a variety of CPUs and architectures. Without an available JRE for a given environment, it is impossible to run Java software.

Differences between JVM implementations

Though implementations of Java Virtual Machines are designed to be compatible, no two JVMs are exactly alike.

For example, garbage collection algorithms vary between one JVM and another, so it becomes impossible to know exactly when memory will be reclaimed. The thread scheduling algorithms are different between one JVM and another (based in part on the underlying operating system), so that it is impossible to accurately predict when one thread will be executed over another.

Initially, this is a cause for concern from programmers new to the Java language. However, it actually has very little practical bearing on Java development. Such predictions are often dangerous to make, as thread scheduling and memory usage will vary between different hardware environments anyway. The power of Java comes from not being specific about the operating system and CPU architecture - to do so reduces the portability of software.
]]> XML http://elearning.cordinize.com/knowledge/index.php?entry=entry080317-111041 XML

Short for Extensible Markup Language, a specification developed by the World Wide Web Consortium (W3C). XML is a pared-down version of SGML, designed especially for Web documents. It allows designers to create their own customized tags, enabling the definition, transmission, validation, and interpretation of data between applications and between organizations

What is a Markup language?

Markup languages are designed for the processing, definition and presentation of text. The language specifies code for formatting, both the layout and style, within a text file. The code used to specify the formatting are called tags. HTML is a an example of a widely known and used markup language.

What is SGML?

Short for Standard Generalized Markup Language, a system for organizing and tagging elements of a document. SGML was developed and standardized by the International Organization for Standards (ISO) in 1986. SGML itself does not specify any particular formatting; rather, it specifies the rules for tagging elements. These tags can then be interpreted to format elements in different ways.
SGML is used widely to manage large documents that are subject to frequent revisions and need to be printed in different formats. Because it is a large and complex system, it is not yet widely used on personal computers. However, the growth of Internet, and especially the World Wide Web, is creating renewed interest in SGML because the World Wide Web uses HTML, which is one way of defining and interpreting tags according to SGML rules.

What is HTML?

Short for Hyper Text Markup Language, the authoring language used to create documents on the World Wide Web. HTML is similar to SGML, although it is not a strict subset. HTML defines the structure and layout of a Web document by using a variety of tags and attributes. The correct structure for an HTML document starts with <HTML> <HEAD> (enter here what document is about)<BODY> and ends with </BODY></HTML>. All the information you'd like to include in your Web page fits in between the <BODY> and </BODY> tags. Tags are also used to specify hypertext links. These allow Web developers to direct users to other Web pages with only a click of the mouse on either an image or word(s).

Aren't XML, SGML, and HTML all the same thing?

Not quite; SGML is the mother tongue, and has been used for describing thousands of different document types in many fields of human activity, from transcriptions of ancient Irish manuscripts to the technical documentation for stealth bombers, and from patients' clinical records to musical notation. SGML is very large and complex, however, and probably overkill for most common office desktop applications.
XML is an abbreviated version of SGML, to make it easier to use over the Web, to make it easier for you to define your own document types, and to make it easier for programmers to write programs to handle them. It omits all the complex and less-used options of SGML in return for the benefits of being easier to write applications for, easier to understand, and more suited to delivery and interoperability over the Web. But it is still SGML, and XML files may still be processed in the same way as any other SGML file.
HTML is just one of many SGML or XML applications—the one most frequently used on the Web.

Why is XML such an important development?

It removes two constraints which were holding back Web developments:
1.Dependence on a single, inflexible document type (HTML) which was being much abused for tasks it was never designed for.
2.The complexity of full SGML, whose syntax allows many powerful but hard-to-program options.

XML allows the flexible development of user-defined document types. It provides a robust, non-proprietary, persistent, and verifiable file format for the storage and transmission of text and data both on and off the Web; and it removes the more complex options of SGML, making it easier to program for.

Why not just carry on extending HTML?

HTML was already overburdened with dozens of interesting but incompatible inventions from different manufacturers, because it provides only one way of describing your information.

XML allows groups of people or organizations to create their own customized markup applications for exchanging information in their domain (music, chemistry, electronics, hill-walking, finance, surfing, petroleum geology, linguistics, cooking, knitting, stellar cartography, history, engineering, rabbit-keeping, mathematics, genealogy, etc).

HTML is now well beyond the limit of its usefulness as a way of describing information, and while it will continue to play an important role for the content it currently represents, many new applications require a more robust and flexible infrastructure.









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]]> Enterprise Java Beans (EJB) http://elearning.cordinize.com/knowledge/index.php?entry=entry080307-034929 Enterprise Java Beans (EJB)

What is EJB?
Enterprise JavaBeans (EJB) technology is the server-side component architecture for Java Platform, Enterprise Edition (Java EE). EJB technology enables rapid and simplified development of distributed, transactional, secure and portable applications based on Java technology.When compared with other distributed component technologies such as Java RMI and CORBA, the EJB architecture hides most the underlying system-level semantics that are typical of distributed component applications, such as instance management, object pooling, multiple threading, and connection pooling.

Why to use EJB?

If an application is small in scope and is not required to be highly scalable, you can use J2EE components, such as servlets, together with direct JDBC connectivity to build it. However, as the application complexity grows or the number of concurrent users increases, the use of EJBs makes it much easier to partition and scale the application. In this case, using EJBs gives you some significant advantages.

When to use EJB?
EJBs are required in the following scenarios.

i. When the application is distributed: When the resources and data are distributed across multiple sites, then it is ideal to go for an application that is based on EJBs. Choose EJB when you know your application will need to scale beyond initial low usage levels and support multiple, concurrent users.

ii. When the application is performance-centric, use of EJBs and the application server provide high performance and very good scalability.

iii. Declaratively manage transactions. When transaction management is required to ensure data integrity, EJBs may be used. In EJB, you merely specify whether a bean's methods require, disallow, or can be used in the context of a transaction. The EJB container will manage your transaction boundaries appropriately.

iv. Declaratively manage security. The EJB model allows you to indicate a security role that the user must be assigned to in order to invoke a method on a bean.

v. Separation of Business Logic. The most significant difference between a web application using only servlets and one using servlets with EJBs is that the EJB model mandates a separation between display and business logic. This can be achieved using Servlets and DAO also
]]> Abstract class vs Interface http://elearning.cordinize.com/knowledge/index.php?entry=entry080305-100018 Abstract class vs Interface

An abstract class can have shared state or functionality. An interface is only a promise to provide the state or functionality. A good abstract class will reduce the amount of code that has to be rewritten because it's functionality or state can be shared. The interface has no defined information to be shared
In java you can inherit from one (abstract) class to "provide" functionality and you can implement many interfaces to "ensure" functionality

A simple three line concept

Use an abstract class when you want to inherit only from the parent
Use an interface when you want to inherit from multiple sources
Use both when you want a basic behavior from the parent and extra features from other sources.

Is there a performance overhead in using either an abstract class or an interface?

Abstract class is faster than interface
we write a program using abstract class in that abstract class. we declare abstract methods and variables. If we want that methods and variable for another class we extends that abstract class which method and variable we want to declare.

eg: //take an example class shape
abstract class shape
{
int a,b,c;
String s1;
abstract area(int);
abstract area(int a, string s);
}
Here area is used every class ie square, rectangle, triangle etc.. so which shape we want we extends this abstract. so it is simple to compare of interface
In interface we declare all methods if not needed that method that time also we must defined so it will take lot of time and memory usage

Why we are? and when we are using Interfaces ?

Interfaces are useful when you do not want classes to inherit from unrelated classes just to get the required functionality. For example, let bird be a class with a method fly(). It will be ridiculous for an aeroplane to inherit from bird class just because it has the fly() method. Rather the fly() method should be defined as an interface and both bird and aeroplane should implement that interface.

When should I use an interface instead of an abstract class

Abstract class is an incomplete implementation of some concept. This incomplete implementation may be different in different context. Derived class implements the abstract class in its context.
Interface defines contract or standard. Implementation of the interface has to follow the contract or standard. Interfaces are more used to set these types of standards or contracts.

For example, In an application there are different editors. There are different toolbars, which can be used on these editors like navigation tool bar. In order to use this tool bar editor should implement that functionality.

So there can be interfaces like - navigation - search – save and modify.

If an editor implements all three, all toolbars will be enabled. If one, then only one will be enabled and implementation of these interface differs from context to context.

In the same example myAbstractEditor can be a class, which implements basic functionality of the editor. Where setting different controls, getting values from them can be abstract, which will depend on editor to editor. ]]> SOA http://elearning.cordinize.com/knowledge/index.php?entry=entry080106-153601
A Service Oriented Architecture is a collection of self-contained services that can communicate with each other. A Service Oriented Architecture is a collection of self-contained services that can communicate with each other.

Key characteristics of services:
loosely coupled
coarse grained
typically published & available for invocation

Defining services at a “business level” enables quick composition of end-to-end business processes, delivering on the promise of greater IT flexibility and agility
]]> Welcome To Knowledge Rack http://elearning.cordinize.com/knowledge/index.php?entry=entry080101-142209